4 National Management Measures to
Control Nonpolnt Source Pollution
from Hydromodification
e?
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'"
United States Environmental Protection Agency
Office of Water
Washington, DC 20460
(4503T)
EPA 841-B-07-002
July 2007
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National Management Measures
to Control Nonpoint Source Pollution from Hydromodification
Nonpoint Source Control Branch
Office of Wetlands, Oceans and Watersheds
U.S. Environmental Protection Agency
Office of Water
July 2007
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Disclaimer
This document provides technical guidance to states, territories, authorized tribes, and the
public for managing hydromodification and reducing associated nonpoint source
pollution of surface and ground water. At times, this document refers to statutory and
regulatory provisions, which contain legally binding requirements. This document does
not substitute for those provisions or regulations, nor is it a regulation itself. Thus, it does
not impose legally-binding requirements on EPA, states, territories, authorized tribes, or
the public and may not apply to a particular situation based upon the circumstances. EPA,
state, territory, and authorized tribe decision makers retain the discretion to adopt
approaches to manage hydromodification and reduce associated NPS pollution of surface
and ground water on a case-by-case basis that differ from this guidance where
appropriate. EPA may change this guidance in the future.
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Table of Contents
Table of Contents
Chapter 1: Introduction 1-1
What is Hydromodification? 1-1
Why is NFS Guidance on Hydromodification Important? 1-2
Purpose and Scope of the Guidance 1-4
Document Organization 1-4
Activities to Control NFS Pollution 1-5
Historical Perspective 1-5
Federal Programs and Funding 1-5
Introduction to Management Measures 1-7
Channelization and Channel Modification (Chapters) 1-8
Dams (Chapter 4) 1-9
Streambank and Shoreline Erosion (Chapter 5) 1-9
Chapter 2: Background 2-1
Key Geomorphic Functions of Streams 2-1
Discharge, Slope, and Sinuosity 2-1
Erosion, Transport, and Deposition of Sediment 2-2
Dynamic Equilibrium 2-2
Longitudinal View of Channels 2-4
Disruption of Dynamic Equilibrium 2-6
General Impacts of Channelization and Channel Modifications 2-6
Physical Impacts 2-6
Chemical Impacts 2-7
Biological and Habitat Impacts 2-8
Impacts Associated with Specific Hydromodification Actions 2-10
Channel Straightening and Deepening 2-10
Channel Lining 2-10
Channel Narrowing 2-11
Channel Widening 2-11
Culverts and Bridges 2-11
Urbanization 2-12
Agricultural Drainage 2-13
Shorelines 2-14
Shoreline Processes 2-14
Deposition and Erosion 2-15
Common Natural and Anthropogenic Causes of Coastal Land Loss 2-16
Impacts Associated with Dams 2-16
Water Quality in the Impoundment/Reservoir 2-18
Water Quality Downstream of a Dam 2-21
Suspended Sediment and Reduced Discharge 2-21
Biological and Habitat Impacts 2-22
Impacts Associated with Dam Removal 2-23
Physical Changes: Upstream Impacts 2-24
Physical Changes: Downstream Impacts 2-24
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Table of Contents
Biological Changes: Upstream Impacts 2-25
Biological Changes: Downstream Impacts 2-26
Chapter 3: Channelization and Channel Modification 3-1
Management Measure 1: Physical and Chemical Characteristics of Channelized or
Modified Surface Waters 3-2
Management Practices for Management Measure 1 3-3
Planning and Evaluation 3-3
Operation and Maintenance Programs 3-4
Grade Control Structures 3-4
Levees, Setback Levees, and Floodwalls 3-5
Noneroding Roadways 3-5
Streambank Protection and Instream Sediment Load Controls 3-6
Vegetative Cover 3-7
Summary of Physical and Chemical Practices 3-8
Management Measure 2: Instream and Riparian Habitat Restoration 3-10
Management Practices for Management Measure 2 3-10
Planning and Evaluation 3-11
Biological Methods/Models 3-11
Temperature Restoration Practices 3-12
Geomorphic Assessment Techniques 3-13
Expert Judgment and Checklists 3-16
Operation and Maintenance Activities 3-16
Chapter 4: Dams 4-1
Management Measure 3: Erosion and Sediment Control for the Construction of New
Dams and Maintenance of Existing Dams 4-4
Management Practices for Management Measure 3 4-5
Erosion Control Practices 4-5
Runoff Control 4-7
Erosion and Sediment Control (ESC) Plans 4-8
Management Measure 4: Chemical and Pollutant Control at Dams 4-10
Management Practices for Management Measure 4 4-11
Management Measure 5: Protection of Surface Water Quality and Instream and
Riparian Habitat 4-12
Management Practices for Management Measure 5 4-14
Practices for Improving Water Quality 4-14
Watershed Protection Practices 4-15
Reservoir Aeration Practices 4-16
Practices to Improve Oxygen Levels in Tailwaters 4-16
Practices to Restore or Maintain Aquatic and Riparian Habitat 4-17
Practices to Maintain Fish Passage 4-18
Removal of Dams 4-19
Chapter 5: Streambank and Shoreline Erosion 5-1
Management Measure 6: Eroding Streambanks and Shorelines 5-3
Management Practices for Management Measure 6 5-5
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Vegetative Practices 5-5
Structural Approaches 5-7
Integrated Systems 5-8
Planning and Regulatory Approaches 5-9
Chapter 6: Guiding Principles 6-1
Using a Watershed Approach 6-3
Smart Growth 6-6
Low Impact Development 6-7
Project Design Considerations 6-8
General Design Factors 6-8
Assessment 6-9
Engineering Considerations 6-10
Incorporating Monitoring and Maintenance of Structures 6-11
Chapter 7: Practices for Implementing Management Measures 7-1
Advanced Hydroelectric Turbines 7-7
Bank Shaping and Planting 7-9
Beach Nourishment 7-10
Behavioral Barriers 7-12
Branch Packing 7-14
Breakwaters 7-15
Brush Layering 7-17
Brush Mattressing 7-19
Bulkheads and Seawalls 7-21
Check Dams 7-22
Coconut Fiber Roll 7-23
Collection Systems 7-25
Construct Runoff Intercepts 7-26
Constructed Spawning Beds 7-27
Construction Management 7-28
Dormant Post Plantings 7-29
Encourage Drainage Protection 7-30
Equipment Runoff Control 7-31
Erosion and Sediment Control (ESC) Plans 7-32
Erosion Control Blankets 7-35
Establish and Protect Stream Buffers 7-37
Fish Ladders 7-38
Fish Lifts 7-40
Flow Augmentation 7-41
Fuel and Maintenance Staging Areas 7-43
Gated Conduits 7-44
Groins 7-45
Identify and Address NFS Contributions 7-46
Soil Erosion Control 7-46
Mine Reclamation 7-46
Animal Waste Control 7-47
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Correcting Failing Septic Systems 7-47
Land Use Planning 7-47
Identify and Preserve Critical Areas 7-48
Conservation Easements 7-48
Leases 7-49
Deed Restrictions 7-49
Covenants 7-49
Transfer of Development Rights (TDRs) 7-49
Joint Planting 7-50
Labyrinth Weir 7-51
Levees, Setback Levees, and Floodwalls 7-52
Live Crib walls 7-54
Live Fascines 7-56
Live Staking 7-58
Locate Potential Land Disturbing Activities Away from Critical Areas 7-60
Marsh Creation and Restoration 7-61
Modifying Operational Procedures 7-62
Mulching 7-63
Noneroding Roadways 7-64
General Road Construction Considerations 7-64
Road Shape and Composition 7-65
Slope Stabilization 7-65
Wetland Road Considerations 7-66
Pesticide and Fertilizer Management 7-67
Phase Construction 7-69
Physical Barriers 7-70
Pollutant Runoff Control 7-72
Preserve Onsite Vegetation 7-73
Reregulation Weir 7-74
Reservoir Aeration 7-75
Retaining Walls 7-77
Return Walls 7-78
Revegetate 7-79
Revetment 7-80
Riparian Improvements 7-82
Riprap 7-83
Root Wad Revetments 7-84
Rosgen's Stream Classification Method 7-86
Scheduling Projects 7-88
Sediment Basins/Rock Dams 7-89
Sediment Fences 7-91
Sediment Traps 7-92
Seeding 7-93
Selective Withdrawal 7-94
Setbacks 7-95
Shoreline Sensitivity Assessment 7-97
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Table of Contents
Environmental Sensitivity Mapping 7-97
USGS Coastal Classification (Coastal & Marine Geology Program) 7-98
USGS National Assessment of Coastal Vulnerability to Sea-Level Rise 7-98
Site Fingerprinting 7-99
Sodding 7-100
Soil Protection 7-101
Spill and Water Budgets 7-102
Spill Prevention and Control Program 7-103
Spillway Modifications 7-104
Surface Roughening 7-105
Toe Protection 7-106
Training—ESC 7-107
Transference of Fish Runs 7-108
Tree Armoring, Fencing, and Retaining Walls or Tree Wells 7-109
Tree Revetments 7-110
Turbine Operation 7-112
Turbine Venting 7-113
Vegetated Buffers 7-114
Vegetated Filter Strips 7-115
Vegetated Gabions 7-116
Vegetated Geogrids 7-118
Vegetated Reinforced Soil Slope (VRSS) 7-120
Water Conveyances 7-121
Wildflower Cover 7-122
Wind Erosion Controls 7-123
Wing Deflectors 7-124
Chapter 8: Modeling Information 8-1
Available Models and Assessment Approaches 8-2
Examples of Channel Modification Activities and Associated Models/Practices 8-15
Modeling for Impoundments 8-15
Modeling for Estuary Tidal Flow Restrictions 8-15
Modeling for Estuary Flow Regime Alterations 8-16
Temperature Restoration Practices 8-16
Selecting Appropriate Models 8-17
Chapter 9: Dam Removal Requirements, Process, and Techniques 9-1
Requirements for Removing Dams 9-1
Dam Removal Process 9-2
Sediment Removal Techniques 9-3
References Cited References-1
Additional Resources Resources-1
Appendix A: U.S. Environmental Protection Agency Contacts A-l
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Table of Contents
Figures
Figure 2.1 Cross-section of a Stream Channel 2-1
Figure 2.2 Factors Affecting Channel Degradation and Aggradation 2-3
Figure 2.3 Example of Aggradation 2-4
Figure 2.4 Three Longitudinal Profile Zones 2-5
Figure 2.5 Overview of a Pool, Riffle, and Run 2-5
Figure 5.1 Shoreline Erosion: Before and After Photos 5-1
Figure 7.1 Dune Nourishment 7-10
Figure 7.2 Dry Beach Nourishment 7-10
Figure 7.3 Profile Nourishment 7-11
Figure 7.4Nearshore Bar Nourishment 7-11
Figure 7.5 Branch Packing 7-14
Figure 7.6 Breakwaters - View of Presque Isle, Pennsylvania 7-15
Figure 7.7 Single and Multiple Breakwaters 7-16
Figure 7.8 Brush Layering: Plan View 7-17
Figure 7.9 Brush Layering: Fill Method 7-18
Figure 7.10 Brush Mattress 7-20
Figure 7.11 Typical Bulkhead Types 7-21
Figure 7.12 Coconut Fiber Roll 7-23
Figure 7.13 Coconut Fiber Roll 7-24
Figure 7.14 Live Posts 7-29
Figure 7.15 Erosion Control Blanket 7-35
Figure 7.16 Fish Ladder at Feather River Hatchery, Oroville Dam, CA 7-38
Figure 7.17 Possible Planform Shapes for Groins 7-45
Figure 7.18 Transition from Groin Field to Natural Shoreline 7-45
Figure 7.19 Joint Planting 7-50
Figure 7.20 Live Crib wall 7-55
Figure 7.21 Live Fascine 7-57
Figure 7.22 Live Staking 7-59
Figure 7.23 Types of Road Surface Shapes 7-65
Figure 7.24 Revetment Alternatives 7-81
Figure 7.25 Riprap Diagram 7-83
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Table of Contents
Figure 7.26 Root Wad, Log, and Boulder Revetment with Footer: Plan View 7-84
Figure 7.27 Rootwad, Log, and Boulder Revetment with Footer: Section 7-85
Figure 7.28 Tree Revetment 7-110
Figure 7.29 Tree Revetment: Section View 7-111
Figure 7.30 Vegetated Gabion 7-116
Figure 7.31 Vegetated Geogrid 7-119
Figure 7.32 VRSS Structure After Construction 7-120
Figure 7.33 Established VRSS Structure 7-120
Tables
Table 1.1 Leading Sources of Water Quality Impairment Related to Human Activities for
Rivers, Lakes, and Estuaries 1-3
Table 2.1 Common Causes of Coastal Land Loss 2-16
Table 4.1 Types of Dams 4-2
Table 4.2 Examples of Erosion and Sediment Control Plan Requirements for Select States 4-8
Table 7.1 Practices for Hydromodification Management Measures 7-2
Table 8.1 Models Applicable to Hydromodification Activities 8-2
Table 8.2 Assessment Models and Approaches 8-10
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Chapter 1: Introduction
Chapter 1: Introduction
The Nation's aquatic resources are among its most valuable assets. Although environmental
protection programs in the United States have improved water quality during the past 35 years,
many challenges remain. Significant strides have been made in reducing the impacts of discrete
pollutant sources, but some aquatic ecosystems remain impaired, due in part to complex
pollution problems caused by nonpoint source (NFS) pollution.1 Of special concern are the
problems in our streams, lakes, estuaries, aquifers, and other water bodies caused by runoff that
is inadequately controlled or treated. These problems include changes in flow, increased
sedimentation, higher water temperature, lower dissolved oxygen, degradation of aquatic habitat
structure, loss offish and other aquatic populations, and decreased water quality due to increased
levels of nutrients, metals, hydrocarbons, bacteria, and other constituents.
What is Hydromodification?
USEPA (1993) defines hydromodification as the "alteration of the hydrologic characteristics of
coastal and non-coastal waters, which in turn could cause degradation of water resources."
Examples of hydromodification in streams include dredging, straightening, and, in some cases,
complete stream relocation. Other examples include construction in or along streams,
construction and operation of dams and impoundments, channelization in streams, dredging, and
land reclamation activities. Hydromodification can also include activities in streams that are
being done to maintain the stream's integrity such as removing snags.2 Some indirect forms of
hydromodification, such as erosion along streambanks or shorelines, are caused by the
introduction or maintenance of structures in or adjacent to a waterbody and other activities,
including many upland activities, that change the natural physical properties of the waterbody.
EPA has grouped hydromodification activities into three categories: (1) channelization and
channel modification, (2) dams, and (3) streambank and shoreline erosion. The following
definitions are offered to clarify the hydromodification activities associated with these three
categories:
Channelization and channel modification include activities such as straightening,
widening, deepening, and clearing channels of debris and sediment. Categories of
channelization and channel modification projects include flood control and
drainage, navigation, sediment control, infrastructure protection, mining, channel
and bank instability, habitat improvement/enhancement, recreation, and flow
control for water supply (Watson et al., 1999). Channelization activities can play
a critical role in NFS pollution by increasing the timing and delivery of pollutants,
including sediment, that enter the water. Channelization can also be a cause of
higher flows during storm events, which potentially increases the risk of flooding.
1 For more information on NFS pollution, go to EPA's website at http://www.epa.gov/owow/nps.
2 A tree or branch embedded in a lake or stream bed and constituting a hazard to navigation; a standing dead tree.
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Chapter 1: Introduction
Dams3 are artificial barriers on waterbodies that impound or divert water and are
built for a variety of purposes, including flood control, power generation,
irrigation, navigation, and to create ponds, lakes, and reservoirs for uses such as
livestock watering, municipal water supply, fish farming, and recreation. While
these types of dams are constructed to provide benefits to society, they can
contribute to NFS pollution. For example dams can alter flows, which ultimately
can cause impacts to water quality (changes to temperature or dissolved gases)
and biological/habitat (disruption of spawning or altering of plant and benthic
communities) above and below the dam.
Streambank and shoreline erosion are the wearing away of material in the area
landward of the bank along non-tidal streams and rivers. Streambank erosion
occurs when the force of flowing water in a river or stream exceeds the ability of
soil and vegetation to hold the banks in place. Eroded material is carried
downstream and redeposited in the channel bottom or in point bars located along
bends in the waterway. Shoreline erosion occurs in large open waterbodies, such
as the Great Lakes or coastal bays and estuaries, when waves and currents sort
coarser sands and gravels from eroded bank materials and move them in both
directions along the shore away from the area undergoing erosion. While the
underlying forces causing the erosion may be different for Streambank and
shoreline erosion, the results (erosion and its impacts) are usually similar. It is
also important to note that Streambank and shoreline erosion are natural processes
and that natural background levels of erosion also exist. However, human
activities along or adjacent to streambanks or shorelines may increase erosion and
other nonpoint sources of pollution.
Why is NPS Guidance on Hydromedification Important?
Hydromodification is one of the leading sources of impairment in our nation's waters. According
to the National Water Quality Inventory: 2000 Report to Congress (USEPA, 2002a), there are
almost 3.7 million miles of rivers and streams4 in the United States. Approximately 280,000
miles of assessed rivers and streams in the United States are impaired for one or more designated
uses, which include aquatic life support, fish consumption, primary and contact recreation,
drinking water supply, and agriculture. Many of the pollutants causing impairment are delivered
to surface and ground waters from diffuse sources, such as agricultural runoff, urban runoff,
hydrologic modification, and atmospheric deposition of contaminants. The leading causes of
3 Dams are defined according to Title 33 of the Code of Federal Regulations, section 222.6(h) (2003) as all artificial
barriers together with appurtenant works which impound or divert water and which (1) are 25-feet or more in height
or (2) have an impounding capacity of 50 acre-feet or more. Barriers that are six-feet or less in height, regardless of
storage capacity or barriers that have a storage capacity at maximum water storage elevation of fifteen acre-feet or
less regardless of height are not included. Federal regulations define dams for the purpose of ensuring public safety.
For example, 33 CFR 222.6 states objectives, assigns responsibilities, and prescribes procedures for implementation
of a National Program for Inspection of Non-Federal Dams. Most states use this or a very similar definition, which
creates a category of dams that requires some form of inspection to ensure that they are structurally sound. Dams
smaller than those defined above, such as those used to create farm ponds, are authorized under the NRCS program.
4 Approximately 700,000 miles (19%) of the total 3.7 million miles of rivers and streams in the United States were
assessed for the National Water Quality Inventory: 2000 Report to Congress (USEPA, 2002a).
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Chapter 1: Introduction
beneficial use impairment (partially or not supporting one or more uses) are nutrients, sediment,
pathogens (bacteria), metals, pesticides, oxygen-depleting materials, and habitat alterations
(USEPA, 2002a).
The National Water Quality Inventory: 2000 Report to Congress (USEPA, 2002a) identified
hydrologic modifications (i.e., hydromodification) as a leading source of water quality
impairment in assessed surface waters. Of the 11 pollution source categories listed in the report,
hydromodification was ranked as the second leading source of impairment in assessed rivers,
second in assessed lakes, and sixth in assessed estuaries (Table 1.1). Three major types of
hydromodification activities—channelization and channel modification, dams, and streambank
and shoreline erosion—change a waterbody's physical structure as well as its natural functions.
Many hydromodification activities are necessary because of human activities. For example,
hardening of streambanks to correct headcutting and streambank erosion is often necessary
because of changes in landuse that increase impervious surfaces. While hydromodification
activities are intended to provide some form of benefit (e.g., levees for reducing flooding,
electricity from hydroelectric dams, or bulkheads to reduce shoreline erosion and protect
valuable property), there may be unintended consequences resulting from the activity. To
illustrate, levees may provide local flood reduction by keeping storm flows from spreading onto
flood plains. However, these same levees may alter riparian wetland habitat that once relied on
seasonal flooding.
Table 1.1 Leading Sources of Water Quality Impairment Related to Human Activities for
Rivers, Lakes, and Estuaries (USEPA, 2002a)
Sources3
Rivers and Streams
Agriculture (48%)b
Hydrologic Modification (20%)c
Habitat Modification (14%)d
Urban Runoff /Storm Sewers
(13%)
Forestry (1 0%)
Municipal Point Sources (10%)
Resource Extraction (1 0%)
Lakes, Ponds, and Reservoirs
Agriculture (41%)
Hydrologic Modification (18%)
Urban Runoff/Storm Sewers
(18%)
Nonpoint Sources (14%)
Atmospheric Deposition (1 3%)
Municipal Point Sources (12%)
Land Disposal (1 0%)
Estuaries
Municipal Point Sources (37%)
Urban Runoff/Storm Sewers
(32%)
Industrial Discharges (26%)
Atmospheric Deposition (23%)
Agriculture (18%)
Hydrologic Modification (14%)
Resource Extraction (12%)
a Excluding unknown, natural, and "other" sources.
b Values in parentheses represent the approximate percentage of surveyed river miles, lake acres, or estuary square
miles that are classified as impaired due to the associated sources.
0 Hydrologic modifications include flow regulation and modification, dredging, and construction of dams. These
activities may alter a lake's habitat in such a way that it becomes less suitable for aquatic life (USEPA, 2002a).
d Habitat modifications result from human activities, such as flow regulation, logging, and land-clearing
practices. Habitat modifications—changes such as the removal of riparian (stream bank) vegetation—can make a
river or stream less suitable for the organisms inhabiting it (USEPA, 2002a).
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Chapter 1: Introduction
Purpose and Scope of the Guidance
National summaries, such as those shown in Table 1.1, are useful in providing an overview of
the magnitude of problems associated with hydromodification. Solutions, however, are usually
applied at the local level. For example, in Maryland, the Shore Erosion Task Force, after
investigating shore erosion in the state, published recommendations to be implemented under a
Comprehensive Shore Erosion Control Plan. To initiate statewide planning, the Maryland
Department of Natural Resources established partnerships with two coastal counties that were
significantly affected by shoreline erosion. These state-local partnerships enable the state to
better identify and correct shoreline erosion problems throughout Maryland (MDNR, 2001).
State and local elected officials and agencies, landowners, developers, environmental and
conservation groups, and others play a crucial role in working together for protecting,
maintaining, and restoring water resources that are impacted by hydromodification activities.
These local efforts, in aggregate, form the basis for changing the status of hydromodification as a
national problem.
This guidance document provides background information about NFS pollution and offers a
variety of solutions for reducing NFS pollution resulting from hydromodification activities. The
background information provided in Chapter 2 includes a discussion of sources of NFS pollution
associated with hydromodification and how the generated pollutants enter the Nation's waters.
Chapter 3 (Channelization and Channel Modification), Chapter 4 (Dams), and Chapter 5
(Streambank and Shoreline Erosion) present technical information about how certain types of
NFS pollution can be reduced or eliminated.
Since hydromodification is not associated with localized impacts and solutions, Chapter 6
provides a discussion on the broad concept of assessing and addressing water quality problems
on a watershed level. Chapter 7 provides detailed information for practices that can be used to
implement the management measures presented in this guidance. Chapter 8 provides a discussion
of available models and assessment approaches that could be used to determine the effects of
hydromodification activities. Chapter 9 summarizes additional dam removal information,
including permitting requirements, process, and techniques for dam removal. The primary goal
of this guidance document is to provide technical assistance to states, territories, tribes, local
governments, and the public for managing hydromodification and reducing associated NFS
pollution.
Document Organization
This document is divided into the following chapters:
• Chapter 1: Introduction
• Chapter 2: Background
• Chapter 3: Channelization and Channel Modification
• Chapter 4: Dams
• Chapter 5: Streambank and Shoreline Erosion
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Chapter 1: Introduction
• Chapter 6: Guiding Principles
• Chapter 7: Practices for Implementing Management Measures
• Chapter 8: Modeling Information
• Chapter 9: Dam Removal Requirements, Process, and Techniques
• References Cited
• Additional Resources
• Appendix A: Federal, State, Nonprofit, and Private Financial and Technical Assistance
Programs
• Appendix B: U.S. Environmental Agency Contacts
Activities to Control NPS Pollution
Historical Perspective
During the first 15 years of the national program to abate and control water pollution (1972-
1987), EPA and the states focused most of their water pollution control activities on traditional
point sources, which are stationary locations or fixed facilities from which pollutants are
discharged; any single identifiable source of pollution (e.g., a pipe, ditch). EPA and the states
have regulated these point sources through the National Pollutant Discharge Elimination System
(NPDES) permit program established by section 402 of the Clean Water Act (CWA).5 The
NPDES program functions as the primary regulatory tool for assuring that state water quality
standards are met. NPDES permits, issued by an authorized state or EPA, contain discharge
limits designed to meet water quality standards and national technology-based effluent
regulations.
In 1987, in view of the progress achieved in controlling point sources and the growing national
awareness of the increasingly dominant influence of NPS pollution on water quality, Congress
amended the CWA to focus greater national efforts on nonpoint sources.
Federal Programs and Funding
The CWA establishes several reporting, funding, and regulatory programs that address pollutants
carried in runoff that is not subject to confinement or treatment. These programs relate to
watershed management and nonpoint source control. Readers are encouraged to use the
information contained in this guidance to develop nonpoint source management programs/plans
that comprehensively address the following EPA programs:
• Section 319 Grant Program. Under section 319 of the CWA, EPA awards funds to states
and eligible tribes to implement NPS management programs. These funds can be used for
projects that address nonpoint source related sources of pollution, including
hydromodification.6
• Clean Water State Revolving Fund. The Clean Water State Revolving Fund (CWSRF)
program is an innovative method of financing environmental projects. Under the
5 For more information on the NPDES program, refer to EPA's NPDES website at http://cfpub.epa.gov/npdes.
6 More information about the section 319 program is provided at http://www.epa.gov/owow/nps/cwact.html.
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Chapter 1: Introduction
program, EPA provides grants or "seed money" to all 50 states plus Puerto Rico to
capitalize state loan funds. The states, in turn, make loans to communities, individuals,
and others for high-priority water quality activities. As money is paid back into the
revolving fund, new loans are made to other recipients. When funded with a loan from
this program, a project typically costs much less than it would if funded through the bond
market. Many states offer low or no interest rate loans to small and disadvantaged
communities. In recent years, state programs have begun to devote an increasing volume
of loans to nonpoint source, estuary management, and other water-quality projects.
Eligible NPS projects include almost any activity that a state has identified in its nonpoint
source management plan. Such activities include projects to control runoff from
agricultural land; conservation tillage and other projects to address soil erosion;
development of streambank buffer zones; and wetlands protection and restoration.7
• Total Maximum Daily Loads. Under section 303(d) of the CWA, states are required to
compile a list of impaired waters that fail to meet any of their applicable water quality
standards. This list, called a 303(d) list, is submitted to Congress every 2 years, and states
are required to develop a Total Maximum Daily Load (TMDL) for each pollutant causing
impairment for waterbodies on the list.8
• Water Quality Certification. Section 401 of the CWA requires that any applicant for a
federal license or permit to conduct any activity that "may result in any discharge" into
navigable waters must obtain a certification from the state or tribe in which the discharge
originates that the discharge will comply with various provisions of the CWA, including
sections 301 and 303. The federal license or permit may not be issued unless the state or
tribe has granted or waived certification. The certification shall include conditions, e.g.,
"effluent limitations or other limitations" necessary to assure that the permit will comply
with the state's or tribe's water quality standards or other appropriate requirements of
state or tribal law. Such conditions must be included in the federal license or permit.
• National Estuary Program. Under the National Estuary Program, states work together to
evaluate water quality problems and their sources, collect and compile water quality data,
and integrate management efforts to improve conditions in estuaries. To date, 28 estuaries
have been accepted into the program. Estuary programs can be an excellent source of
water quality data and can provide information on management practices.9
• Safe Drinking Water Act. Many areas, especially urban fringe areas, need to maintain or
improve the quality of surface and ground waters that are used as drinking water sources.
This act requires states to develop Source Water Assessment Reports and implement
Source Water Protection Programs. Low- or no-interest loans are available under the
Drinking Water State Revolving Fund (SRF) Program.10
7 Additional information about CWSRF is available at http://www.epa.gov/OWM/cwfinance/cwsrf/index.htm.
8 More information on the TMDL program and 303(d) lists is provided at http://www.epa.gov/owow/tmdl.
9 More information on the National Estuary Program is provided at http://www.epa.gov/nep.
10 More information about the Safe Drinking Water Act and Source Water Protection Programs can be found at
http://www.epa.gov/safewater/sdwa/index.html and http://www.epa.gov/safewater/protect.html.
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Chapter 1: Introduction
• Wildlife Habitat Incentives Program (WHIP). WHIP11 is a voluntary program authorized
by the Farm Security and Rural Investment Act of 2002 (Farm Bill)12 that enables
landowners to apply for technical and financial assistance to improve wildlife habitat.
The program is administered by the Natural Resources Conservation Service (NRCS),
which works with private landowners and operators, conservation districts, and federal,
state, and tribal agencies to improve terrestrial and aquatic habitats. NRCS and
participants work together to create a wildlife habitat development plan that includes a
cost-share agreement. Continued assistance after habitat development includes
monitoring, review of management guidelines, and technical advice. WHIP funds may
also be used for dam removal. Additional information is available from an NRCS WHIP
fact sheet.13
Two excellent resources for learning more about the CWA and the many programs established
under it are The Clean Water Act: An Owner's Manual (Killam, 2005) and The Clean Water Act
Desk Reference (WEF, 1997).
Introduction to Management Measures
Management measures may be implemented as part of state, tribal, or local programs to control
nonpoint source pollution for a variety of purposes, including protection of water resources,
aquatic wildlife habitat, and land downstream from increased pollution and flood risks. They can
be used to guide in the development of a runoff management program. Management measures
establish performance expectations and, in many cases, specify actions that can be taken to
prevent or minimize nonpoint source pollution from hydromodification activities. Management
measures might control the delivery of NFS pollutants to receiving water resources by:
• Minimizing pollutants available (source reduction)
• Retarding the transport and/or delivery of pollutants, either by reducing water
transported, and thus the amount of the pollutant transported, or through deposition of the
pollutant
• Remediating or intercepting the pollutant before or after it is delivered to the water
resource through chemical or biological transformation
Management measures are generally designed to control a particular type of pollutant from
specific activities and land uses. The intent of the six management measures in this guidance
document is to provide information for addressing and considering the NFS pollution potential
associated with hydromodification activities. Implementation of management measures can
minimize and control hydromodification NFS pollution through erosion and sediment control,
chemical and pollutant control, management of instream and riparian habitat restoration, and
protection of surface water quality.
11 http://www.nrcs.usda.gov/programs/whip
12 http://www.nrcs.usda.gov/programs/farmbill/2002
13 http://www.nrcs.usda.gov/programs/farmbill/2002/pdf/WHIPFct.pdf
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Chapter 1: Introduction
Activities associated with these management measures may be regulated by federal, state, or
local law (e.g., section 404 of the Clean Water Act). These measures do not supersede such
requirements. Sometimes regulatory authorities may appear to conflict, as is sometimes the case
of the CWA and water use and distribution. CWA sections 101(g) and 510 specifically allow for
resolution of the conflict by placing water use and its distribution under the authority of the
states, thus protecting any state agreements on "water rights." Users of this NFS guidance should
recognize that the applicability of the guidance provided in this document will remain subject to
state statutes, interstate compacts, and international treaties. As such, this guidance does not
recommend or require any management measures or practices that hinder a state's ability to
exercise existing water rights, which provide water for municipal, industrial, and agricultural
needs. For further information regarding specific state policies on water rights and regulations of
water use, contact the appropriate state water agency. Contact information is generally provided
on state government Web sites.
This document also lists and describes management practices for each management measure.
Management practices are specific actions taken to achieve, or aid in the achievement of, a
management measure. A more familiar term might be best management practice (BMP). The
word "best" has been dropped for the purposes of this guidance (as it was in the Coastal
Management Measures Guidance (USEPA, 1993)) because the adjective is too subjective. The
"best" practice in one area or situation might be entirely inappropriate in another area or
situation. The practices listed in this document have been found by EPA to be representative of
the types of practices that can be applied successfully to achieve the management measures. EPA
recognizes that there is often site-specific, regional, and national variability in the selection of
appropriate practices, as well as in the design constraints and pollution control effectiveness of
practices. The practices presented for each management measure are not all-inclusive. States or
local agencies and communities might wish to apply other technically and environmentally
sound practices to achieve the goals of the management measures.
Channelization and Channel Modification (Chapter 3)
Channelization can cause a variety of instream flow changes and may result in the faster delivery
of pollutants to downstream areas. Channel modification might result in a combination of
harmful effects (higher flows or increased risk of downstream flooding) and beneficial effects
(local flood control or enhanced flushing in a stream channel). The management measures for
channelization and channel modification are intended to protect waterbodies by ensuring proper
planning before a proposed project is implemented. Planning and evaluation can help to identify
and prevent local and downstream problems before a project is started. An added benefit of
planning and evaluation is to correct or prevent detrimental changes to the instream and riparian
habitat associated with the project. Implementation of the management measures can also ensure
that operation and maintenance programs for existing projects improve physical and chemical
characteristics of surface waters and restore or maintain instream and riparian habitat when
possible.
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Chapter 1: Introduction
Management Measure 1: Physical and Chemical Characteristics of Surface Water:
Ensure that the planning process for new hydromodification projects addresses changes
to physical and chemical characteristics of surface waters that may occur as a result of the
proposed work. For existing projects, ensure that operation and maintenance programs
use any opportunities available to improve the physical and chemical characteristics of
surface waters.
Management Measure 2: Instream and Riparian Habitat Restoration: Correct or
prevent detrimental changes to instream and riparian habitat from the impacts of
channelization and channel modification projects, both proposed and existing.
Dams (Chapter 4)
Because of their instream locations, any construction activities associated with dams have the
potential to introduce sediment and other pollutants into adjacent waterbodies. Construction
activities, chemical spills during dams operation or maintenance, and changes in the quantity and
quality of water held and released by a dam may alter the nature of the waterbody. The
management measures for dams are intended to be applied to the construction of new dams, as
well as any construction activities associated with the maintenance of existing dams. They can
also be applied to dam operations that result in the loss of desirable surface water quality, and
instream and riparian habitat.
Management Measure 3: Erosion and Sediment Control: Prevent sediment from
entering surface waters during the construction or maintenance of dams.
Management Measure 4: Chemical and Pollutant Control: Prevent downstream
contamination from pollutants associated with dam construction and operation and
maintenance activities.
Management Measure 5: Protection of Surface Water Quality and Instream and
Riparian Habitat: Protect the quality of surface waters and aquatic habitat in reservoirs
and in the downstream portions of rivers and streams that are influenced by the quality of
water contained in the releases (tailwaters) from reservoir impoundments.
Streambank and Shoreline Erosion (Chapter 5)
NPS pollution might result from the rapid increase in erosion of streambanks caused by
increased flow rates associated with urbanization in a watershed. Not only is the land adjacent to
these eroding streambanks unnaturally carried away, but these eroded soils are carried
downstream and deposited in often undesirable locations. Shorelines erode more severely as the
result of poorly planned and implemented shoreline protection projects located nearby. Habitats
can be buried and wetlands can be filled. As runoff upstream increases, more erosion results on
downstream streambanks. The streambank and shoreline erosion management measure promotes
the necessary actions required to correct streambank and shoreline erosion where it must be
controlled. Because erosion is a natural process, this management measure is not intended to be
applied to all erosion occurring on streambanks and shorelines.
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Chapter 1: Introduction
Management Measure 6: Eroding Streambanks and Shorelines: Protect streambanks
and shorelines from erosion and promote institutional measures that establish minimum
setback requirements or measures that allow a buffer zone to reduce concentrated flows
and promote infiltration of surface water runoff in areas adjacent to the shoreline.
Channelization and channel modification and dams represent forms of hydromodification that
are direct results of human activities—someone performs a construction activity directly in or
along a stream, river, or shoreline. For example, a town constructs concrete lined channels along
a stream passing through the city limits to reduce stream meandering and prevent flooding.
Another example is the construction (many years ago) of a dam in a stream for hydropower at a
grist mill. Streambank and shoreline erosion are forms of hydromodification that result from
direct and indirect human activities. For example, a streambank is eroding at a much faster rate
because of recent development activities on shore that result in increased runoff, which is
causing increased bank erosion. Another example is a concrete seawall that is protecting property
at one location, but causing increased erosion on adjacent properties.
This distinction between forms of hydromodification and impacts from hydromodification is
important when contrasting the relationship between Chapter 3 (Channelization and Channel
Modification) and Chapter 5 (Streambank and Shoreline Erosion). Many of the operation and
maintenance solutions presented in Chapter 3 are also practices that can be used to stabilize
streambanks and shorelines as presented in Chapter 5. For example, a stream channel that has
been hardened with vertical concrete walls to prevent local flooding and limit the stream to its
existing channel (to protect property built along the stream channel), may benefit from operation
and maintenance practices that use opportunities to replace the concrete walls with an
appropriate vegetative or combined vegetative and non-vegetative structures along the
streambank when possible. These same practices may be applicable to stabilize downstream
streambanks that are eroding and creating a nonpoint source pollution problem because of the
upstream development and hardened streambanks.
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Chapter 2: Background
Chapter 2: Background
There are differing views on defining the stability of a stream channel and other waterbodies.
From a navigation perspective, a stream channel is considered stable if shipping channels are
maintained to enable safe movement of vessels. Landowners with property adjacent to a stream
or shoreline might consider the waterbody to be stable if it does not flood and erosion is minimal.
Ecologists might find some erosion of streambanks and meandering channels to be a part of
natural evolution (i.e., changes that are not induced by humans) and consider long-term changes
like these to be quite acceptable (Watson et al., 1999). In any case, new and existing
channelization projects, construction and maintenance of dams, and streambank and shoreline
erosion problems should be evaluated with these differing perspectives in mind and a balance of
these perspectives should be taken into account when constructing or maintaining a project.
Often, multiple priorities can be maintained with good up-front planning and communication
among the different stakeholders involved.
Key Geomorphic Functions of Streams
Discharge, Slope, and Sinuosity
Figure 2.1 is a cross-section of a typical stream channel. The thalweg is the deepest part of the
channel. The sloped bank is known as the scarp. The term discharge is used to describe the
volume of water moving down the channel per unit time (usually described in the United States
as cubic foot per second (cfs)). Discharge is the product of the area through which the water is
flowing (in square feet) and the average velocity of the water (in feet per second). If discharge in
a channel increases or decreases, there must be a corresponding change in streamflow velocity
and/or flow area.
thalweg
Figure 2.1 Cross-section of a Stream Channel (FISRWG, 1998)
Channel slope is an especially key concept when dealing with hydromodification projects. It is
the difference in elevation between two points in the stream divided by the stream length
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Chapter 2: Background
between the two points. Stream sinuosity greatly affects stream slope. Sinuosity is the stream
length between two points on a stream divided by the valley length between the two points. A
meandering stream moving through a valley has a lower slope than a straight stream.
Erosion, Transport, and Deposition of Sediment
All streams accomplish three basic geomorphic tasks:
• Erosion—the detachment of soil particles along the stream bed and banks
• Sediment transport—the movement of eroded soil particles in streamflow
• Sediment deposition—the settling of eroded soil particles in the water or on land as water
recedes
These processes largely determine the size and shape of the channel, both laterally and
longitudinally. The ability to accomplish these geomorphic tasks is related to stream power, the
product of slope and discharge. Slope directly affects flow velocity. Consequently, a shallow,
meandering stream with low slope generates less stream power, and has lower erosion and
sediment-transport capacity, than a deep, straight stream.
In addition to sinuosity, roughness along the boundaries of a stream area is also important in
determining streamflow velocity and stream power. The rougher the channel bottom and banks,
the more they are able to slow down the flow of water. The level of roughness is determined by
many conditions including:
• Type and spacing of bank vegetation
• Size and distribution of sediment particles
• Bedforms
• Bank irregularities
• Other miscellaneous obstructions
Tractive stress, also known as shear stress, describes the lift and drag forces that work to create
erosion along the stream bed and banks. In general, the larger the sediment particle, the more
stream power is needed to dislodge it and transport it downstream. When stream power decreases
in the channel, larger sediment particles are deposited back to the stream bed.
Dynamic Equilibrium
One of the primary functions of a stream is to move particles out of the watershed. Erosion,
sediment transport, and deposition occur all the time at both large and small scales within a
channel. A channel is considered stable when the average tractive stress maintains a stable
streambed and streambanks. That is, sediment particles that erode and are transported
downstream from one area are replaced by particles of the same size and shape that have
originated in areas upstream. Lane (1955) qualitatively described this relationship as:
Qs * D oc Qw * S
Where: Qs = Sediment discharge, D = Sediment particle size, Qw = Streamflow,
S = Stream slope
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Chapter 2: Background
When all four variables are in balance, the channel is stable, or in dynamic equilibrium.
Lane's channel variable relationships can be visualized as a pan balance with sliding weights
(Figure 2.2). Sediment discharge is placed on one pan and streamflow on the other. The hook
holding the sediment load pan can slide back and forth based on changes in sediment size.
Likewise, the hook holding the streamflow can slide according to changes in slope.
If a disturbance or stream modification occurs that causes a variable to change, one or more of
the other variables must change in order to maintain the balance. During an imbalanced phase,
the scale indicator will point to either degradation or aggradation. This indicates that the channel
will try to adjust and regain equilibrium by either increasing sediment discharge by scouring the
bottom or eroding its banks (degradation) or decreasing sediment discharge by depositing
sediment on the bottom (aggradation), depending on the circumstance.
For example, if stream slope is decreased and streamflow remains the same (i.e., streamflow pan
slides toward the center), the balance will tip and aggradation will occur (Figure 2.3).
Alternatively, if streamflow increases and slope remains the same (i.e., more weight on the
streamflow pan), degradation will occur. No matter the scenario, this basic relationship between
the variables will hold true and aggradation or degradation will cease only when the system
reaches equilibrium. This can occur naturally over time, or through management practices
designed to deal with the "balancing" issue.
I. i i i i i—i
sediment size (D)
Figure 2.2 Factors Affecting Channel Degradation and Aggradation (FISRWG, 1998)
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Chapter 2: Background
Figure 2.3 Example of Aggradation (Adapted from FISRWG, 1998)
Longitudinal View of Channels
The geomorphic processes that define the size and shape of channels can be observed in large
and small scale longitudinal views. The overall longitudinal view of many streams can be
divided into three general zones (Schumm, 1977):
• Headwater zone—characterized by steep slopes with sediment erosion as the most
dominant geomorphic process.
• Transfer zone—characterized by more sinuous channel patterns and wider floodplains
with sediment transfer as the most dominant geomorphic process.
• Deposition zone—characterized by lower slope and higher channel sinuosity than the
other zone and is the primary deposition area for watershed sediment.
Key characteristics of each zone are summarized in Figure 2.4.
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Chapter 2: Background
Mountain headwater streams
tlow swiftly down steep
slopes and cut a deep
V-shaped valley.
Rapids and
waterfalls are
common.
Low-elevation streams
merge and flow down
gentler slopes, The
valley broadens and
the river begins to
meander.
At an even lower
elevation a river wanders
and meanders slowly
across a broad, nearly flat
valley. At its mouth it may
divide into many separate
channels as it flows across
a delta built up of river-
borne sediments and into
the sea.
Figure 2.4 Three Longitudinal Profile Zones (FISRWG, 1998)
At a smaller scale, natural-forming channels are usually characterized by a series of riffles,
pools, and runs. These structures are primarily associated with the thalweg, which meanders
within the channel (Figure 2.5).
Riffles are shallow, turbulent,
and swiftly flowing stretches of
water that flow over partially or
totally submerged rocks.
Deeper areas at stream bends
are the pools and can be
classified as large-shallow,
large-deep, small-shallow, and
small-deep. Runs are the
sections of a stream with little
or no surface turbulence that
connect pools and riffles.
The distribution in streamflow
velocity and stream power
throughout the riffle/pool/run POOL
sequence impact the
geomorphic tasks. The stream Figure 2.5 Overview of a Pool, Riffle, and Run (USEPA, 1997b)
bottom of a riffle is at a higher
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Chapter 2: Background
elevation than the stream areas surrounding it. Consequently, the water flowing in a run from
riffle to pool has the highest velocity near the center of the channel just under the surface (i.e.,
away from the roughness associated with channel boundaries). On reaching a bend, angular
momentum forces the highest velocity flow to the outside of the bend and, given enough tractive
stress, causes erosion to the bank (cutbanks). Meanwhile on the inside of the bend deposition
often occurs because of decreasing flow velocity. Importantly, these and other characteristics of
the riffle/pool/run sequence create unique habitats which allow different species to live,
reproduce, and feed.
Disruption of Dynamic Equilibrium
Changes caused by (or exacerbated by) hydromodification projects and other human activities
can lead to a disruption of the dynamic equilibrium of the stream channel. If, for example, a
modification occurs that causes a change in sediment discharge, channel slope, or streamflow,
one or more of the other variables will be imbalanced and the channel will usually try to adjust
and regain equilibrium by either increasing sediment discharge by scouring the bottom or
eroding its banks (degradation) or decreasing sediment discharge by depositing sediment on the
bottom (aggradation) (Biedenharn et al., 1997; Watson et al., 1999). In some cases, alterations to
a stream channel can result in local or system-wide channel instability (FISRWG, 1998).
General Impacts of Channelization and Channel Modifications
Channelization and channel modifications are undertaken for many purposes including flood
control, navigation, drainage improvement, and reduction of channel migration potential.
Modifications also occur in association with the installation of culverts and bridges, urbanization
of the watershed, and agricultural drainage. These changes may result in several physical and
chemical impacts.
Physical Impacts
The most significant physical impact of channelization and channel modifications is the
movement or deposition of sediment. Sediment erodes from stream banks and beds, is washed
downstream in faster moving water, deposited in areas of slower flows, and transported into new
areas of streams or other receiving waters. Critical habitat can be changed when channelization
or channel modification projects alter the dynamic equilibrium of a stream and change sediment
transport or deposition characteristics. Re-establishing equilibrium may take some time to occur
and have long-lasting effects to habitat and water quality conditions.
Channel modification and channelization can lead to increased erosion in some areas of the
stream, which produces sediment. Sediment can be dislodged and transported directly from the
waterbody's shoreline, bank, or bottom. Sediment being transported by a stream is referred to as
the sediment load, which is further classified as the bed load (those particles moving on or near
the bed, or bottom of the channel) and the suspended load (those particles moving in the water
column). Hydromodification typically results in more uniform channel cross-sections, steeper
stream gradients, and reduced average pool depths.
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Chapter 2: Background
An increase in the sediment load could lead to increased turbidity, which then may cause an
increase in stream temperature because the darker sediment particles absorb heat (USEPA,
1997b). Changes in water temperature can influence several abiotic chemical processes, such as
dissolved oxygen concentrations, sorption of chemicals onto particles, and volatilization rates.
Water temperature influences reaeration rates of oxygen from the atmosphere. Dissolved oxygen
concentrations in water are inversely related to temperature; solubility of oxygen decreases with
increasing water temperature. In addition, sorption of chemicals to particulate matter and
volatilization rates are influenced by changes in water temperature. Sorption often decreases with
increasing temperature and volatilization increases with increasing temperature (University of
Texas, 1998).
An increased sediment load that contains significant organic matter can increase the sediment
oxygen demand (SOD). The SOD is the total of all biological and chemical processes in
sediment that consume oxygen (USEPA, 2003a). These processes occur at or just below the
sediment-water interface. Most of the SOD at the surface of the sediment is due to the biological
decomposition of organic material and the bacterially facilitated nitrification of ammonia, while
the SOD several centimeters into the sediment is often dominated by the chemical oxidation of
species such as iron, manganese, and sulfide (Walker and Snodgrass, 1986 from USGS, 1997;
Wang, 1980). Increases in SOD can lead to lower levels of dissolved oxygen, which can be
harmful to aquatic life.
A channel that is deepened or widened can result in slower and/or shallower flow. Reduced
stream velocities can result in more sediment deposits to a stream segment. When more sediment
is deposited in an area of a stream, critical habitats can be buried, channels may become
unstable, and flooding increases. In tidal areas, channel modification activities, such as
deepening a channel to allow for larger ships to access a shoreline, may require frequent
maintenance to remove accumulating sediment because of changes in flow patterns.
Chemical Impacts
A variety of chemicals can be introduced into surface waters when channelization and channel
modification activities alter flow and sediment transport characteristics. Nutrients, metals, toxic
organic compounds, pesticides, and organic materials can enter the water in eroding soils along
banks and move throughout a stream as flow characteristics change. Changing temperatures and
dissolved oxygen levels may lead to alterations in the bioavailability of metals and toxic
organics. Complex chemical conditions can significantly change when stream flow and
sedimentation characteristics change, resulting in new and/or potentially harmful forms of
chemicals affecting instream or benthic organisms.
It is important to remember that many of the physical and chemical changes are interrelated. For
a more detailed discussion of the impacts associated with chemical and physical changes to
surface waters, see Restoration of Aquatic Ecosystems (NRC, 1992). The following discussion
provides examples of impacts that may be present as a result of different kinds of channelization.
For a more detailed discussion of types of channelization projects and potential impacts, see
Watson etal. (1999).
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Chapter 2: Background
Biological and Habitat Impacts
Pools, riffles, and runs create a mixture of flows and depths and provide a variety of habitats to
support fish and invertebrate life (USEPA, 1997b). The shallow, turbulent, and swiftly flowing
stretches of riffle water are well oxygenated and have a "patchy distribution of organisms,"
which means that different types of organisms are naturally found in different parts of the riffle.
Pools can also be large or small and shallow or deep and support a wide variety of aquatic
species. Sediments can deposit in pools, which can lead to the formation of islands, shoals, or
point bars.
Changes in habitat and biological communities following hydromodification of a channel can be
highly site-specific and complex. The physical and chemical alterations resulting from
channelization impact various habitats and biological communities, including instream algae,
fish, macroinvertebrate populations, and bank or floodplain vegetation. Mathias and Moyle
(1992) compared unchannelized and channelized sections of the same stream and found a much
higher diversity of many organisms, including aquatic invertebrates, fish, and riparian
vegetation, in the unchannelized sections of the stream. Adams and Maughan (1986) compared
the benthic community in a small headwater stream, prior to and after channelization. They
found that the pathways of organic input shifted from materials associated with leaf fall and
runoff to materials associated with periphyton production. Accompanying this change was a shift
of the assemblage from shredder domination to grazer domination and a decrease in diversity.
Biological and habitat impacts caused by channelization can result from increased stream
velocity, decreases in pool and riffle habitat complex, decrease in canopy cover, increase in the
solar radiation reaching the channel, channel incision, and increases in sediment.
Channelization of a stream may increase velocity due to increased channel slope and decreased
friction with the bank and bed material. Changes in the velocity may cause an impact to
organisms within the channel. For example, fish may have to expend more energy to stay in
swifter currents and their source of food may be swept downstream. Studies have demonstrated
that fisheries associated with channelized streams can be far less productive that those of non-
channelized streams (Jackson, 1989). Increased rates of erosion as a result of increased velocities
downstream of a channelization feature can also create unstable streambanks, which could lead
to increased streambank erosion, higher risks of flooding, and ultimately negative impacts to
aquatic organisms.
Channelization can result in a more uniform stream channel that is void of the pool and riffle
habitat complex or obstructions, such as woody debris inputs. As repeatedly observed, this can
result in changes to the biological community. Negishi et al. (2002) observed a decrease in the
total density of macroinvertebrates in the middle of a channelized stream and a decrease in taxon
richness in the middle and edge of a channelized stream. An overall reduction in habitat
heterogeneity is likely responsible for the reduction in species diversity and the increased
abundance of those species favored by the altered flows that is typically observed (Allan, 1995).
On medium-sized, unregulated rivers, Benke (2001) found that habitat-specific invertebrate
biomass was highest on snags, followed by the main channel and then the floodplain. It was
concluded that invertebrate productivity from these habitats has likely been significantly
diminished as a result of snag removal, channelization, and floodplain drainage (Benke, 2001).
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Chapter 2: Background
The survival of the Gulf Coast walleye (Stizostedion vitreum) relies on the availability of
appropriate spawning habitat, such as large woody debris, that locally reduce current velocity.
Channelization and the removal of structures have been identified as activities of concern that
could threaten the survival of the species (VanderKooy and Peterson, 1998). In one experiment,
an assessment of water quality using environmental indices, such as macroinvertebrate
communities, found that channelization and deforestation resulted in a completely different and
less varied biocommunity (Bis et al., 2000). A lower persistence of the macroinvertebrate
assemblage in the channelized stream was attributed to the lower availability of flow such as
backwaters and inundated habitats (Negishi et al., 2002). In a study by Kubecka and
Vostradovsky (1995), low fish populations were attributed to channelization of the riverbed.
The channelization of a river can also result in a decrease in canopy cover and an increase in the
solar radiation reaching the channel. Bis et al. (2000) found that an increase in incident radiation
on a river resulted in increased algal productivity and a significant decrease in scrapers, a
macroinvertebrate that feeds on periphyton or algae growing on plant surfaces. Increased water
temperatures can also lead to a shift in the algal community to predominately planktonic algal
communities, which disrupts the aquatic food chain (Galli, 1991). The combination of increased
water temperatures and loss of riparian vegetation falling into the stream (which provides both
food and cover) may be responsible for the decrease in macroinvertebrates. Increased solar
radiation on a channelized stream can act to decrease productivity by reaching the level of
photoinhibition; a decrease in productivity due to excessive amounts of solar radiation. The
temperature of the water can also be increased to the extent that it adversely impacts organisms.
Elevated temperatures disrupt aquatic organisms that have narrow temperature limits, such as
trout, salmon, and many aquatic insects.
Incision of a channel, a common impact of channelization, disconnects the channel from the
floodplain by lowering the riverbed relative to the floodplain and decreasing the occurrence of
overbank flow. Channel incision or downcutting has rarely been found to directly affect the
biotic ecosystem, but indirect changes in habitat conditions are significant. Channel incision
decreases habitat heterogeneity and, as a result, biodiversity (Tachet, 1997). An analysis of forest
overstory, understory, and herbaceous strata along a channelized and unchannelized stream
showed that there was a difference in terms of size-class structure and woody debris quantity
(Franklin et al., 2001). Loss of woody vegetation along riparian zones on a channel that is
incised because of upstream channelization was attributed to a decrease in over bank flooding
and a lowering of the water table as the stream became incised (Steiger et al., 1998). A
comparison of a regulated and an unregulated river in Colorado's Green River Basin found a
difference in riparian vegetation composition. The regulated river supported banks with wetland
species that survive in anaerobic soils and terraces with desert species adapted to xeric soil
conditions. The unregulated river supported riparian vegetation that changed along a more
gradual environmental continuum from a river channel to a high floodplain (Merritt and Cooper,
2000).
Sediment affects the use of water in many ways. When the rate of erosion changes, transport and
deposition of sediment also changes. Excessive quantities of sediment can bury benthic
organisms and the habitat offish and waterfowl. Suspended solids in the water reduce the
amount of sunlight available to aquatic plants, cover fish spawning areas and food supplies, fill
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Chapter 2: Background
rearing pools, reduce beneficial habitat structure in stream channels, smother coral reefs, clog the
filtering capacity of filter feeders, and clog and harm the gills offish. Those fish species that rely
on visual means to get food may be restricted by increased turbidity. Sedimentation effects
combine to reduce fish, shellfish, coral, and plant populations and decrease the overall
productivity of lakes, streams, estuaries, and coastal waters.
Impacts Associated with Specific Hydromodification Actions
Channel Straightening and Deepening
Channels are straightened for a multitude of reasons, such as directing water away from a
particular structure or area and reducing local flooding. Channelization that involves
straightening of the stream channel increases the slope of the channel, which results in higher
discharge velocities. Impacts associated with increased water velocities include more streambank
and streambed erosion, higher sediment loads, changes in pools, riffle, and run structure, and
increased transport of nutrients and other pollutants (FISRWG, 1998; Simons and Senturk,
1992).
Channelization can also result in alterations to the base level of the stream, including channel
downcutting or incision of a section of the stream, which raise the height of the floodplain
relative to the riverbed and decrease the frequency of overbank flow. When streams reach flood
stage and flow into the floodplain, velocities decrease. The reduction in overbank flow reduces
sediment deposition and the sediment storage potential of the floodplain (Wyzga, 2001). A
change in the downstream base level of a stream can create an unstable stream system
(Biedenharn et al., 1997).
Headcutting is the deepening of a waterway caused by channelization or localized stream-bed
mining. Headcutting severely impacts the physical integrity of a stream, as streambanks become
unstable and are more prone to eroding and sloughing. Bank failures may result, removing
streamside vegetation and introducing significant amounts of sediment into the waterway. As
sediments build on the stream bottom, natural substrate is covered and stream depth decreases.
Water quality often diminishes as temperatures rise due to less shading by riparian vegetation
and increased water surface area with decreased depth. The rapid alteration to stream habitat
caused by headcutting is usually detrimental to aquatic wildlife. Various organizations, such as
the U.S. Army Corps of Engineers, the Natural Resources Conservation Service (NRCS), and the
Missouri Department of Conservation, are involved in projects to reduce headcutting (CSU, n.d.;
MDC, 2007; USGS, 2000).
Channel Lining
The sides of channels can be lined with materials such as metal sheeting, concrete, wood, or
stone to prevent erosion of a particular section of stream channel or stream bank. The artificially
lined areas can reduce the friction between the channel and flowing water, leading to an increase
in velocity. The increased velocity and thus the increased erosive potential of the flowing water
are not able to erode the artificially lined channel area and can result in augmented erosion
downstream as well as increased downstream flooding (Brookes, 1998). Lining the channel also
removes aquatic habitat and important substrates that are essential to aquatic life.
EPA841-B-07-002 2-10 July 2007
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Chapter 2: Background
Channel Narrowing
Narrowing of a stream channel often occurs when flood control measures such as levees and
floodwalls are implemented. By narrowing a stream channel, the water is forced to flow through
a more confined area and thus travels at an increased velocity (FISRWG, 1998). The increased
velocity in turn increases the stream's erosive potential and ability to transport sediment. This
can lead to increased erosion of the streambank and shoreline in downstream locations.
When a channel is made narrower, the water depth increases and the surface area exposed to the
solar radiation and ambient temperature decreases, especially in the warmer months. This can
cause a decrease in the water temperature. Increased depth may also reduce the surface area of
the water in contact with the atmosphere and affect the transfer of oxygen into the water.
In a naturally flowing stream, floods are responsible for such processes as redistributing
sediment from the river bottom to form sandbars and point bar deposits. Stream channel
modifications to reduce flood damage, such as levees and floodwalls, often narrow the stream
width, increasing the velocity of the water and thus its erosive potential. This can lead to
increased erosion of the streambank and shoreline in downstream locations (FISRWG, 1998).
Channel Widening
Channel widening is often performed to increase a channel's ability to transport a larger volume
of water. The design is often based on volumes of water that occur during flood events. The
design of a channel modification project to increase the channel's ability to transport a large
volume of water will determine the characteristic of the water flow. The widening of a channel
can result in a channel with a capacity to transport water that far exceeds the typical daily
discharge. This results in a typical flow that is shallow and wide. As a result of increased contact
with the streambed and streambank, there is increased friction and a decreased water velocity.
The decrease in velocity causes sediment to settle out of the water column and accumulate within
the stream channel. This accumulation of sediment can decrease the capacity of the stream
channel. The decreased depth and increased surface area of the water exposed to solar radiation
and ambient air temperatures can lead to an increase in water temperature. A change in water
temperature can influence dissolved oxygen concentrations as dissolved oxygen solubility
decreases with increasing water temperature.
Where tidal flow restrictors cause impoundments, there may be a loss of streamside vegetation,
disruption of riparian habitat, changes in the historic plant and animal communities, and decline
in sediment quality. Restricted flows can impede the movement offish or other aquatic life. Flow
alteration can reduce the level of tidal flushing and the exchange rate for surface waters within
coastal embayments, with resulting impacts on the quality of surface waters and on the rates and
paths of sediment transport and deposition.
Culverts and Bridges
The presence of culverts and bridges along a channel can have an impact on the physical and
chemical qualities of the water. A culvert can be in the form of an arch over a channel or a pipe
that encircles a channel, and it functions to direct flow below a roadway or other land use. A
culvert or the supports of a bridge can confine the width of a channel forcing the water to flow in
a smaller area and thus at a higher velocity. Impacts associated with a higher flow velocity
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Chapter 2: Background
include increased erosion. An arch culvert maintains the natural integrity of the stream bottom.
In addition, as compared with the natural substrate that can be found using an arch culvert
without concrete inverts (floors), a pipe culvert may create less friction with the water flow and
result in an increased flow velocity. The chemical and physical changes associated with
increased erosion and sediment transport capacity would then result.
The culvert acts as a fixed point with a fixed elevation within the stream channel and as the
stream attempts to adjust over time, the culvert remains stationary. Placement of this type of
structure disturbs the natural equilibrium of a channel. A culvert sometimes may have beneficial
attributes when it acts as a grade control structure, and as such, may serve to prevent upstream
migrating incision (headcutting) from moving further up the channel. Depending on the
watershed processes, the culvert may act to preserve the natural equilibrium of a channel.
Urbanization
As humans develop watersheds, the proportions of pervious and impervious land within the
watershed change (most often increasing impervious areas and decreasing pervious areas).
Development also results in reductions in vegetative cover in exchange for increases in houses,
buildings, roads, and other non-vegetative cover. The result is a change in the fate of water from
rainfall events. Generally, as imperviousness increases and vegetative cover is lost:
• Runoff increases
• Soil percolation decreases
• Evaporation decreases
• Transpiration decreases
Increased volumes of runoff resulting from some types of watershed development can result in
hydraulic changes in downstream areas including bank scouring, channel modifications, and
flow alterations (Anderson, 1992; Schueler, 1987). The resulting changes to the distribution,
amount, and timing of flows caused by flow alterations can affect a wide variety of living
resources. As urbanization occurs, changes to the natural hydrology of an area are inevitable.
During urbanization, pervious spaces, including vegetated and open forested areas, are converted
to land uses that usually have increased areas of impervious surface, resulting in increased runoff
volumes and pollutant loadings. Hydrologic and hydraulic changes occur in response to site
clearing, grading, and change in landscape. Water that previously infiltrated the ground and was
slowly released runs off quickly into stream networks. Development, with corresponding
increases in imperviousness, can lead to:
• Increased magnitude and frequency of bankfull and subbankfull floods
• Dimensions of the stream channel that are no longer in equilibrium with its hydrologic
regime
• Enlargement of channels
• Highly modified stream channels (from human activity)
• Upstream channel erosion that contributes greater sediment load to the stream
• Reduced dry weather flow to the stream
• Decreased wetland perimeter of the stream
• Degraded in-stream habitat structure
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Chapter 2: Background
• Reduced large woody debris
• Increased stream crossings and potential fish barriers
• Fragmented riparian forests that are narrower and less diverse
• Decline in water quality
• Increased summer stream temperatures
• Reduced aquatic diversity
The hydraulic changes associated with urbanization have often been addressed with
channelization and channel modification as a solution. Evaluating impacts from urbanization on
a watershed scale and planning solutions on the same watershed scale can often prevent the
transference of upstream problems to downstream locations. There are a variety of management
activities that can reduce the impacts associated with urban development. When these urban
impacts are reduced, additional hydromodification impacts, such as channelization and channel
modification or streambank and shoreline erosion effects, may be reduced. Changes in urban
development practices that result in reduced sediment in runoff can enhance reservoir quality and
lessen the need for management activities to reduce nonpoint source impacts associated with the
operation of dams.l
Agricultural Drainage
Some activities, including channelization and channel modification, that take place within a
watershed, can lead to unintended adverse effects on watershed hydrology. Even when the
intended effect of the watershed activity is to reduce pollution or erosion for an area within a
watershed, the impact of the project to the entire watershed's hydrology should be evaluated.
Since hydrology is important to the detachment, transport, and delivery of pollutants, better
understanding of these effects can lead to reduction of nonpoint source pollution problems
(USEPA, 2003b).
One example of an activity that has been shown to provide localized nonpoint source benefits,
but can negatively affect the hydrology of a watershed, is an agricultural drainage system. The
main purpose of agricultural drainage is to provide a root environment suitable for plant growth,
but it can also be used as a means of reducing erosion and improving water quality. Despite the
localized positive effects of drainage, when drainage water is poor in quality or contains elevated
levels of pollutants, adverse impacts may occur downstream within a watershed. Concentrations
of salts, nutrients, and other crop-related chemicals, such as fertilizers and pesticides can damage
downstream aquatic ecosystems. Many agricultural drainage systems include drain tiles placed
strategically throughout a field to create a network of gravity fed drains. The drain tiles empty
into a collection pipe that drains to a waterbody nearby. With the drain system in place and
operating, water will leave the affected area quicker and at one or more focused points. Water
from the drainage system may erode the banks of unlined surface drains, contribute to flashier
runoff events in the receiving water or downstream, and increase the load of sediment in
drainage water (USEPA, 2003b).
For additional information on hydrologic problems associated with urbanization and management practices that
address urbanization issues, refer to National Management Measures to Control Nonpoint Source Pollution from
Urban Areas (USEPA, 2005d): http://www.epa.gov/owow/nps/urbanmm/index.html.
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Chapter 2: Background
Because of these adverse effects, drainage planners should analyze effluents from these systems
for nutrients and pesticides to determine possible downstream impacts. Care should also be taken
with drainage water so that it does not negatively alter the hydrology of a watershed (F AO,
1997). The degree to which management activities, such as agricultural drainage systems, affect
watersheds beyond their intended purpose should be evaluated. In some cases, a thorough
assessment and thoughtful discussion with key stakeholders is enough to evaluate the potential
impacts of a project on hydrology. However, in many instances, some form of modeling is
probably needed to integrate various small and large impacts of watershed activities. For more
information on agricultural drainage and management practices related to agricultural drainage,
refer to National Management Measures for the Control ofNonpoint Pollution from Agriculture
(USEPA, 2003b).2
Shorelines
A shoreline is defined as the areas between low tide and the highest land affected by storm
waves. The shape and position of shorelines are constantly being modified by the processes of
erosion and deposition by waves and currents (Tarbuck and Lutgens, 2005). NOAA's Coastal
Services Center defines shoreline as "the line of contact between the land and a body of water.
On Coast and Geodetic Survey nautical charts and surveys the shoreline approximates the mean
high water line" (NOAA, 2006).
The shoreline can be divided into three major areas:
1) Coast—the land inland from the base of the sea cliff (produced by the undercutting of
bedrock at sea level by wave erosion).
2) Beach (shore)—the area between low tide level and dunes, sea cliff, or permanent
vegetation. This can be separated into backshore and foreshore.
3) Offshore—the area continuously underwater, which can include a wave build platform.
Shoreline Processes
As mentioned above, the shape and position of shorelines are constantly modified by erosion and
deposition by waves and currents. Waves are agents of erosion, transportation, and deposition of
sediments. Waves can be formed by the following processes (Tulane University, n.d.; University
of Alabama, 2006):
• Wind-generated waves—formed by shear stress between water and air when the wind
speed is higher than about 3 km/hr. Factors that determine the size of waves are wind
velocity, wind duration, and fetch (distance the wind blows over a continuous water
surface).
• Displacement of water—can be caused by activities such as landslides.
• Displacement ofseafloor—can be caused by faulting and volcanic eruptions.
2 Available online at: http://www.epa.gov/owow/nps/agmm/index.html.
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Chapter 2: Background
Wave refraction occurs where wave fronts approach the shore at an angle, but are bent to become
more parallel to the shoreline by frictional drag on the bottom. The part of the wave in shallow
water slows down because of bottom friction, while the part in the deep water keeps moving at
regular speed. Wave refraction causes headland erosion and deposition in bays (Tulane
University, n.d.; University of Alabama, 2006).
Nearshore currents occur in the area from the shoreline to beyond the surf zone and consist of
(Tulane University, n.d.; University of Alabama, 2006):
• Longshore currents move parallel to shore in the same general direction as the
approaching waves. They are produced by the movement of oblique waves in the surf
zone, and can transport large amounts of sediment by longshore drift.
• Rip currents are strong, narrow currents of surface water that flow seaward through the
surf into deeper water. The currents develop in areas with lower wave heights (deeper
water depths).
Deposition and Erosion
Wave erosion and rivers that open into the ocean or lakes can deposit sediment, transported by
longshore currents, developing the following deposit!onal features (Tulane University, n.d.;
University of Alabama, 2006):
1) Beaches—Any strip of sediment that extends from the low-water line inland to a cliff or
zone of permanent vegetation, which is built of material eroded by waves from the
headlands, and material brought down by rivers that carry the products of weathering and
erosion from the land masses. Beaches are protected from the full force of water waves
but are continually modified by wave and current erosion.
2) Spits—A narrow ridge or embankment of sediment forming a finger-like projection from
the shore into the open ocean. Spits typically develop when the sediment being carried by
long-shore drift is deposited where water becomes deeper, such as the mouth of a bay.
3) Baymouth bars—Sand bars that form as a result of longshore drift and completely cross a
bay, sealing it off from the open ocean.
4) Tombolo—A ridge of sand that connects two islands or an island with the mainland,
formed as the result of wave refraction around an island.
5) Tidal inlet—A break in a spit or baymouth bar, caused by storm erosion, through which
tidal currents rush.
6) Barrier islands—Low offshore ridges of sediments that parallel the coast and are
separated from the mainland by lagoons.
Wave erosion can also wear away land features, causing the following types of features to form
(Tulane University, n.d.; University of Alabama, 2006):
1) Sea cliffs—formed by storm wave erosion which undercuts higher land, making it
susceptible to mass wasting. Sea cliffs can erode very slowly or rapidly, depending on the
rock type and wave energy.
2) Wave-cut terrace or platform—produced by the retreat of a sea cliff which slopes gently
in a seaward direction.
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Chapter 2: Background
3) Headlands—occur due to the seaward projections of shore eroded by wave refraction.
Common Natural and Anthropogenic Causes of Coastal Land Loss
Primary causes of coastal land loss, including both natural and anthropogenic causes, are
summarized in Table 2.1 below (USGS, 2004).
Table 2.1 Common Causes of Coastal Land Loss
Agent
Examples
Natural Causes
Erosion
Sediment reduction
Submergence
Wetland deterioration
Waves and currents, storms, landslides
Climate change, stream avulsion, source depletion
Land subsidence, sea-level rise
Herbivory, freezes, fires, saltwater intrusion
Anthropogenic Causes
Transportation
Coastal construction
River modification
Fluid extraction
Climate alteration
Excavation
Wetland destruction
Boat wakes, altered water circulation
Sediment deprivation (bluff retention), coastal structures (jetties,
seawalls)
groins,
Control and diversion (dams, levees)
Water, oil, gas, sulfur
Global warming and ocean expansion, increased frequency and
storms
Dredging (canals, pipelines, drainage), mineral extraction (sand,
mines)
intensity of
shell, heavy
Pollutant discharge, traffic, failed reclamation, burning
Shorelines can also experience increased rates of erosion as a result of hydromodification
activities. Alterations to the sediment sources for beaches can result in erosion. The sediment
supplied to beaches or shorelines can come from a variety of sources including rivers, cliff and
rocky foreshores, the seafloor, or windblown dune materials. Beaches and shorelines at the
mouth of a river are often replenished by fluvial sediment. When changes within the river system
decrease the sediment load carried to the mouth of the river, the result may be decreased
sediment supplies to the shoreline or beach. While the design of each hydromodification system
determines the impacts that will ensue, streambank and shoreline erosion is a common
consequence.
Impacts Associated with Dams
The physical presence and operation of dams can result in changes in water quality and quantity.
Some of the water quality impacts include changes in erosion, sedimentation, temperature,
dissolved gases, and water chemistry. Examples of biological and habitat impacts, which may
result from a combination of physical and chemical changes, include loss of habitat for existing
or desirable fish, amphibian, and invertebrate species; changes from cold water to warm water
species (or inversely, changes from warm water to cold water species); blockage offish passage;
or loss of spawning or necessary habitat.
The impacts associated with dams occur above (upstream) and below (downstream) the dam.
Upstream impacts occur primarily in the impoundment/reservoir created by the presence and
operation of the dam. The area and depth of the impoundment will determine the extent and
EPA841-B-07-002 2-16 July 2007
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Chapter 2: Background
complexity of the upstream and downstream impacts. For example, small, low-head dams with
little impounded areas will exhibit different impacts than large storage dams. Sedimentation and
fish passage issues at the smaller, low-head dam contrast with sedimentation, temperature, fish
passage, flow regulation, and water quality issues that may be associated with the larger storage
dam. The existence of the dam and associated impoundment results in much different water
quality interactions than those associated with the preexisting naturally flowing streams or rivers.
Above dams, activities within the watershed can have significant impacts on water quality within
impoundments and in releases from dams to downstream areas. Watershed activities, such as
agricultural land use, unpaved rural roads, forestry harvesting, or urbanization can lead to
changes in runoff water quantity and quality. Agricultural and forestry practices that lead to
sediment-laden runoff may result in increased sediment accumulation within an impoundment.
Chemicals (e.g., pesticides and nutrients) that are applied on agricultural crops can be carried
with sediment in runoff. Increases in urbanization that result in more impervious areas within a
watershed often result in dramatic changes in the quantity and timing of runoff flows. These
external sources are integrated by the dam and may result in short- and long-term water quality
changes within an impoundment and dam releases.
Water quality in reservoirs and releases from dams are closely linked and scrutinized to uses of
the water. Often, there are multiple potential users who may have differing quality needs and
perceptions. Management of dams includes balancing dam operations, watershed activities,
reservoirs, and downstream water and uses. Dortch (1997) provides an excellent assessment on
water quality considerations in Reservoir Management. Dortch (1997) notes the following about
water quality:
• Temperature regulates biotic growth rates and life stages and defines fishery habitat
(warm, cool, and cold water).
• Oxygen sustains aquatic life.
• Turbidity affects light transmission and clarity.
• Nutrient enrichment is linked to primary productivity (algal growth) and can cause
oxygen depletion, poor taste, and odor problems.
• Organic chemicals and metals may be toxic and accumulate when bound to sediment that
settles in the reservoir.
• Total dissolved solids may be problematic for water supplies and other users.
• Total suspended solids are a transport mechanism for nutrients and contaminants. Solids
may settle in reservoirs and displace water storage volume.
• pH regulates many chemical reactions.
• Dissolved iron, manganese, andsulfide can accumulate in reservoir hypolimnions that
are depleted of oxygen and can cause water quality problems in the reservoir and release
water.
• Pathogens include bacteria, viruses, and protozoa that can cause public health problems.
Water uses include water supply, flood control, hydropower, navigation, fish and wildlife
conservation, and recreation (Dortch, 1997). All of the uses have varying water quality
requirements, ranging from almost none for flood control to high quality needs for water supply,
fish and wildlife conservation, and recreation.
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Chapter 2: Background
Dams act as a barrier to the flow of water, as well as to materials being transported by the water.
This can impact water quality both in the impoundment/reservoir created by the dam and
downstream of the dam. Alteration to the chemical and physical qualities of water held behind a
dam is often a function of the retention time of a reservoir or the amount of time the water is
retained and not able to flow downstream. Water held in a small basin behind a run-of-river dam
may undergo minimal alteration. In contrast, water stored for months or even years behind a
large storage dam can undergo drastic changes that impact the downstream environment when
released (McCully, 2001). A storage dam that impounds a large reservoir of water for an
extended time period will cause more extensive impacts to the physical and chemical
characteristics of the water than a smaller dam with little storage capacity.
Several physical changes are possible when dams are introduced into a stream or river, including
changes in:
• Instream water velocities
• Timing and duration of flows
• Flow rates
• Sediment transport capacities
• Turbidity
• Temperature
• Dissolved gasses
Similarly, changes to water chemistry are possible as a result of damming rivers and streams,
including changes to:
• Nutrients
• Alkalinity and pH
• Metals and other toxic pollutants
• Organic matter
The nature and severity of impacts will depend on the location in the river or stream, in relation
to the upstream or downstream side of the dam, the storage time of the impounded water, and the
operational practices at the dam. Many of the above impacts are also interrelated. For example,
changes in temperature may result in changes in dissolved oxygen levels or changes to pH may
result in changes to nutrient dynamics and the solubility of metals.
Water Quality in the Impoundment/Reservoir
As water approaches a dam from upstream, the stream velocity slows down considerably,
creating a lake-like environment. The water builds up behind the dam and forms a basin (i.e.,
impoundment, reservoir) that is deeper than the previous stream flow. The height of the dam and
its operational characteristics will determine how much water is stored and the length of storage.
The extent of impacted stream area above the dam is influenced by the size of the dam installed,
how much water is released, and how often water is released. For example, a small run-of-the
river dam constructed to divert water for a millrace will have minimal storage capacity and may
only store water for several hours or less. In this case, instream water velocities may decrease,
EPA841-B-07-002 2-18 July 2007
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Chapter 2: Background
but with minimal upstream and downstream effects. Thus, the length of upstream channel that is
impacted should be relatively small.
In contrast, a large flood control dam and reservoir may have many months of storage and
severely alter instream velocities for long distances upstream. Topography surrounding the
original stream channel and storage volume will be important parameters determining the length
of stream channel affected by the large dam. The volume and frequency of discharges from the
dam will also determine how much of the upstream channel is impacted with lower instream
velocities as a result of the dam.
Dams act as a physical barrier to the movement of suspended sediments and nutrients
downstream (McCully, 2001). When the stream flow behind a dam slows, the sediment carrying
capacity of the water decreases and the suspended sediment settles onto the reservoir bottom.
Any organic compounds, nutrients, and metals that are absorbed to the sediment also settle and
can accumulate on the reservoir bottom.
Turbidity associated with sediment varies, depending on particle sizes of the sediment and the
length of time water is held. Longer holding times in the reservoir could result in periodic
episodes of high turbidity from upstream storm events that carry sediment rich stormwater,
especially if the sediment is predominantly very fine clay particles. Turbidity may also increase
as a result of planktonic algal growth in a reservoir.
The increased depth of the water in reservoirs reduces the volume of water exposed to solar
radiation and ambient temperatures. Once the flow is controlled by the operation of the dam and
the reservoir is mixed primarily by winds, temperature variations can become established within
the reservoir. This can cause thermal stratification where, compared to the bottom, surface layers
become warmer in the summer and cooler in the winter. In deeper reservoirs, the deepest layers
may become nearly constant in temperature throughout the year. Changes in temperature can
impact water quality and biological processes in the reservoir, including changes in predominant
fish species. Since the density of water is a function of water temperature, thermal stratification
creates density gradients within the impoundment. As density gradients become established,
exchanges of gases and chemicals between gradients decrease. In a stratified impoundment well
aerated surface waters often do not mix with hypolimnetic water and result in poorly oxygenated
strata below the surface waters.
Nutrient transport is affected by dams, which can trap the nutrients in the
impoundment/reservoir. When nutrients accumulate, the reservoir might become nutrient
enriched (i.e., eutrophic). In warmer seasons, concentrated nutrients in waters exposed to light
can promote growth of algae and other aquatic plants, which consume nutrients and release
oxygen (during photosynthesis) and carbon dioxide (during respiration). When algae and other
aquatic plants complete their growth cycles, they die and sink to the bottom of an impoundment.
Microbial decomposition of the highly organic dead plant materials may release nutrients back
into the water column. Microbial decomposition of the dead plant and algal cells in aerobic
conditions consumes oxygen, which can rapidly deplete bottom waters of dissolved oxygen.
Under anaerobic conditions, microbial decomposition can produce potentially toxic
concentrations of gases, such as hydrogen sulfide.
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Chapter 2: Background
The operational characteristics of a dam will influence nutrient levels in water releases. For
example, water released from the surface of an impoundment may contain seasonally varying
forms and levels of nutrients. During periods of algal growth, releases may contain lower levels
of dissolved nutrients and higher levels of organic materials (algae) containing nutrients. When
algal growth is not occurring, releases may contain higher levels of dissolved nutrients.
Anaerobic (oxygen-depleted) environments, which are typical of deeper waters in reservoirs, can
result in several changes to the water chemistry. For example, as by-products of organic matter
decomposition in an anaerobic environment, ammonia and hydrogen sulfide concentrations can
become elevated (Freeman, 1977; Pozo et al., 1997). Highly acidic (or highly alkaline) waters
tend to convert insoluble metal sulfides to soluble forms, which can increase the concentration of
toxic metals in reservoir waters (FISRWG, 1998).
Changes in one water quality parameter in a reservoir/impoundment can impact other water
quality parameters, causing a cycling of events to occur. For example, increased sedimentation
(from internal or external sources) can lead to more organic matter remaining in the reservoir,
resulting in more biochemical oxygen demand, potentially lower dissolved oxygen, and other
changes to water chemistry, such as pH and metal solubility. Periodic growth and then die-off of
aquatic plants and algae creates additional variable cycling of organic matter in the reservoir.
The following references may provide additional detail on the complex water quality changes
that can occur in impoundments and reservoirs:
• Holdren, C., W. Jones, and J. Taggart. 2001. Managing Lakes and Reservoirs. North
American Lake Management Society and Terrene Institute, in cooperation with the
Office of Water, Assessment and Watershed Protection Division, U.S. Environmental
Protection Agency, Madison, WI.
• Thornton, K.W., B.L. Kimmel, and F.E. Payne. 1990. Reservoir Limnology: Ecological
Perspectives. John Wiley & Sons, Inc., New York.
• U.S. Army Corps of Engineers. N.d. The WES Handbook on Water Quality Enhancement
Techniques for Reservoirs and Tailwaters. U.S. Army Corps of Engineer Research and
Development Center Waterways Experiment Station, Vicksburg, MS.
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Chapter 2: Background
Water Quality Downstream of a Dam
The physical and chemical changes that occur to the water quality in an impoundment/reservoir
have a large impact on the water released downstream of a dam. As previously stated, the
presence of a dam can alter water velocities above and below the dam. In smaller dams with little
storage capacity, velocities may slow locally and recover to an undisturbed state shortly
downstream from the dam. When dams store large volumes of water in a reservoir, the operation
of the dam will have a major impact on the downstream velocities and flows. Unless the dam is
operated to consistently release water at flows
near pre-dam levels, downstream areas will have
flows and velocities that are directly related to
.11 f , , , • , • temperatures fluctuated more diurnally with
the volume of water released in a given time coo^r nighttime temperatures as compared
period. The downstream flow characteristics will
become a function of the operation of the dam,
including the timing and duration of releases, the
depth of reservoir intakes, and other physical
characteristics of the release.
On the Columbia River, research found that
prior to construction of dams, average water
with the existing average water temperatures.
With the dams in place, cooler weather tends
to cool the free flowing river but have little
effect on the average temperature of the
impounded river (USEPA, 2003c).
When dams trap sediment upstream, water released from the dam may be starved of sediment
and have an increase in erosive capacity. Along with trapping sediment, nutrients may also be
trapped above the dam. When the nutrients are trapped and unavailable, sensitive downstream
habitats and populations may be affected.
Whether the water is released from the surface or bottom of the reservoir can have a large impact
on the characteristics of the water. The impacts of water outflows below a dam are an outcome of
the seasonal temperature fluctuations and the outflow positioning. Seasonal temperature profiles
in reservoirs are highly variable and dependent upon a complex set of factors including tributary
inflow, basin morphometry, drawdown and discharge characteristics, and the degree of
stratification (Wetzel, 2001). Compared to natural temperatures, in summer elevated
temperatures in surface water releases can increase downstream river temperatures, whereas
bottom water releases can be expected to decrease water temperatures. The opposite effect is
generally observed in the winter due to changes in the water temperature gradient (USAGE, 1999
in Fidler and Oliver, 2001).
Suspended Sediment and Reduced Discharge
Whether the release water originates from the surface or the bottom of the reservoir, the
suspended sediment has typically settled out of the water column and thus the water released
from behind the dam is usually relatively free from sediment (Simons and Senturk, 1992). This
sediment-free water can easily pick up and carry a sediment load and have an increase in erosive
capacity. Because of the rock lined channels of bank stabilization and navigation projects that
usually occur below these reservoirs, the only place that the clear waters can find the sediments
they need is in the streambed or navigation channel. This leads to channel deepening or bed
degradation, which in turn lowers water tables and drains floodplain channels and backwaters
(Rasmussen, 1999). Streambed and streambanks will continue to erode until an equilibrium
suspended sediment load is established. Without sediment from upstream sources, downstream
streambanks, streambeds, sandbars, and beaches can erode away more quickly (FISRWG, 1998).
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Chapter 2: Background
A reduction in the discharge and sediment load generally results in degradation of the channel
close to the dam and sedimentation downstream due to the increased supply from the erosion
near the dam. Degradation may eventually migrate downstream, but is typically most dramatic
the first few years following construction of the dam (Biedenharn et al., 1997). In addition, the
physical impact of the discharge will depend, in part, on the channel substrate. A fine silt and
sand channel bottom may experience more extensive erosion than a bed rock or cobble substrate.
Lower flow conditions below a dam within a tidally influenced basin can lead to changes in
water chemistry. The impact of lower freshwater flow into estuaries was extensively studied in
San Francisco Bay. Nichols et al. (1986) provide a detailed history of changes to freshwater
inflows to San Francisco Bay. They also provide a summary of the impacts, which include the
ecological and water quality effects. A study comparing an unregulated river and a dam
regulated river found a significant difference in the water quality chemistry, including an
analysis of levels of sodium, potassium, calcium, phosphorus, electrical conductivity, and pH in
the middle and lower reaches of the rivers. These differences were attributed to increased tidal
influence as a result of lower outflow volumes of fresh water from the dam (Colonnello, 2001).
In addition, a decreased discharge from the dam and increased tidal influence can prolong the
flushing time or the time it takes water to move through a system. This causes the nutrients and
pollutants within the water to remain concentrated in areas below the dam near an estuary.
Biological and Habitat Impacts
The presence of a dam may cause physical and chemical changes to the water quality. These, in
turn, can have an impact on the entire biological community including fish, macroinvertebrates,
algae, and streamside vegetation. Impacts to the biological community differ upstream and
downstream of a dam. Dams may disrupt spawning, increase mortalities from predation, change
instream and riparian habitat, and alter plant and benthic communities. Resulting fish populations
after dam construction may thrive and become well established, but could be very different than
populations prior to installing the dam. For example, upstream of the dam, a fish population may
change from a cold-water salmonid fishery to one that is dominated by cool- or warm-water
species. A once thriving native trout population may become a largemouth bass (Micropterus
salmoides) and bluegill (Lepomis macrochirus) dominated system. Similarly, downstream
conditions may also change. In southern states, streams that once supported catfish and other
tolerant warm-water species may now be able to support a trout fishery because of cold-water
releases from bottom waters behind a dam. Although the trout fishery may be viewed as positive
by some, the displaced native warmwater species may not be perceived as beneficial.
Dams prevent the movement of organisms throughout the river system (Morita and Yamamoto,
2002). Researchers found that fragmenting habitat by damming a river caused the disappearance
of a fish species in several upstream locations and further disappearances were predicted (Morita
and Yamamoto, 2002). Recently, some individual cases involving movement of invasive, non-
native aquatic species note the presence of dams as a positive factor. In these cases, dams have
blocked the movement of potentially harmful invasive species.
Flood control and hydropower projects influence a river's hydrograph. For example, in some
regions normal river hydrographs featured a rise in water level elevation corresponding to spring
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Chapter 2: Background
rains. Other geographic areas had stream hydrographs corresponding to snowmelt in the
mountains, or fall rainfall. Native species evolved under these scenarios and used such water
level rises to trigger spawning movements onto floodplains and in the case of birds, for nesting
on islands. Additionally, the stream water level fluctuations were important in providing feeding
and resting areas for spring and fall waterfowl migrations. Under managed scenarios for
commercial navigation, river water level elevations are raised in the spring and held stable
throughout the navigation season, virtually eliminating the triggering mechanisms native species
used to reproduce and complete their life cycles. Because of this, many native riverine species
often fail to spawn or nest, and are becoming increasingly threatened (Rasmussen, 1999).
Additionally, stabilization of periodic flooding has also lead to the loss of ephemeral wetlands
and may lead to the accumulation of sediments in nearshore areas, thus negatively affecting fish
spawning areas (NRC, 1992).
Dams may lead to increased predation offish in several ways. A dam may cause populations of
fish to concentrate on the upstream and downstream sides, which might lead to the likelihood of
increased predation. Changes in the habitat adjacent to a dam can make conditions more suitable
to predation. Dams may cause the migration process to be delayed, which also leads to increased
predation (Larinier, 2000).
The physical and chemical changes to water released from a dam, including reduced streamflow
variability and decreased sediment loads, may also impact benthic communities. Increased water
clarity and reduced streamflow variability just below a dam may result in a greater abundance of
periphyton or other plants as compared with other locations in the river (Stanford and Ward,
1996). A slowed stream flow velocity with decreased turbulence can also encourage the growth
of phytoplankton blooms (Decamps et al., 1988). In contrast, the operation of some hydroelectric
dams with large, sudden releases of water may scour the bottom of the downstream channel to
the extent that there is a nearly complete removal of the plant communities (Allan, 1995).
Impacts Associated with Dam
Removal
Removing a dam affects the flow of
water, movement of sediment and
chemical constituents, and the overall
channel morphology (Academy of
Natural Sciences, 2002) on the
waterway where the dam was located.
The impacts of removing a dam differ
for the upstream and downstream
sections of a waterway.
Changes in the biological community
following the removal of a dam are
difficult to generalize, as they are
highly site specific and can vary in
recovery time from a few months to
The effects of river damming were evaluated in a study
comparing a regulated river to an unregulated river in the
Green River Basin in Colorado. Prior to installation of the
dam in Green River in 1962, Green River and the Yampa
River were similar in riparian vegetation and fluvial
processes. Comparison of the now regulated Green
River and the free-flowing Yampa River found distinctive
vegetation differences between the parks that surround
the rivers. The channel form of Green River has
undergone three stages of morphologic change that have
transformed the historically deep river into a shallow
braided channel. The Yampa River has remained
relatively unchanged. The land surrounding the Green
River now consists of marshes with anaerobic soil that
supports wetland species and terraces with desert
species adapted to xeric soil conditions. The meandering
Yampa River has maintained its original surroundings. Its
frequently flooded bars and high floodplains provide a
wide range of habitats for succession of riparian
vegetation (Merritt and Cooper, 2000).
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Chapter 2: Background
more than a decade. With the removal of a dam, there are changes in the vegetative community
surrounding the stream channel and changes in the biological community within the stream itself.
Physical Changes: Upstream Impacts
The removal of a dam allows the water formerly held behind the dam to flow and will likely
cause the extent of the impoundment area or reservoir area to decrease. As a dam is removed and
the water recedes, sediment is scoured from the bottom and a stream channel returns sometimes
to its pre-dam pathway and sometimes to a newly carved channel. As a channel is formed, areas
that were formerly beneath the impoundment area become exposed. This can leave large areas of
unvegetated and unstable land exposed, which makes these areas likely to undergo erosion and
gully development, increasing the sediment load to the stream.
In time, vegetation will stabilize the newly formed stream banks, reducing erosion and allowing
sediment transport levels to return to natural levels. The nutrient and metal constituents
associated with the sediment will also return to natural levels. As the newly established channel-
like flow develops and the stagnant and deep conditions are removed, the natural temperature
and oxygen levels will be reestablished.
Physical Changes: Downstream Impacts
Once the physical barrier of the dam is removed, a river can flow unrestricted. As the channel is
reformed, the water discharge volume and the stream channel can reach equilibrium. As a result,
a more natural stream flow rate is maintained.
With the removal of a dam, the fate of the trapped sediments is of concern because flooding and
downstream pollution problems can result. On a short-term time scale, the redistribution of the
fine silt and sand sediments that accumulated behind the dam wall may cause an increase in
turbidity and water quality problems. In addition, the impact can be greater if the sediments
contain toxic pollutants, such as metals or bioaccumulative compounds such as mercury or
PCBs. On a short-term time scale, the redistribution of the fine silt and sand sediments increases
the turbidity and can damage spawning grounds, water quality, habitat, and food quality
(American Rivers, 2002a). Suspended sediment loads can have a negative impact on a biological
community and reach lethal levels during dam removal if preventive measures are not
implemented (Doyle et al., 2000).
After a dam is removed and the sediment that has been trapped behind the dam is redistributed,
natural sediment transport levels return. As a result, the constituents typically sorbed to sediment,
including nutrients and metals, are no longer found localized in excess. Normal sediment
transport levels typically result in a river bottom with a higher percentage of rocky substrate.
Gravel and cobblestones located below the sediment may be exposed or may be transported from
upstream locations as the flow rate of the river increases. This unrestricted flow and transport of
sediment and gravel may also play a key role in restoring sediments to downstream locations and
coastal beaches (USDOI, 1995). The removal of a dam and the return of natural flow rates
should also help to restore a river's natural water temperature range and oxygen levels.
Short-term chemical changes to the water quality, including the possibility of supersaturation of
nitrogen gas directly following the removal of a dam, can cause aquatic animals to experience
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Chapter 2: Background
adverse conditions. This can include gas bubble disease, in which nitrogen bubbles form in the
blood and tissues and block capillaries by embolism (Colt, 1984; Soderberg, 1995). Adverse
effects can be seen when the dissolved nitrogen level reaches 102% and at 105% widespread fish
mortalities are possible (Dryden Aqua, 2002). Supersaturation was an issue in the 1992 removal
of Little Goose Dam on the Snake River (American Rivers, 2002a). If a reservoir is drawn down
slowly, the severity of the impact of supersaturation on aquatic organisms can be lessened
(American Rivers, 2002a).
Biological Changes: Upstream Impacts
Following the removal of a dam, a return to the normal temperature range, flow rates, and
oxygen levels supports the return of native aquatic vegetation species. Still water impoundments
support aquatic vegetation that is free floating or that does not need to be strongly rooted, while
free-flowing systems support plants that are rooted strongly enough to resist being uprooted by
the water current (WRM, 2000).
As the water recedes and the formerly impounded area becomes exposed, vegetation can begin to
colonize the area. Sometimes, the exposed area may be colonized by invasive plant species,
which are able to remain for several years and prevent other vegetation from becoming
established.
The removal of a dam and the subsequent drawdown of water from the impoundment area can
affect the wetlands formerly bordering the impoundment area. As the dam is removed, the water
table typically begins to drop. The elevation of the wetlands and the extent of the water table
drawdown determine whether the wetland areas dry up and what changes will occur in the
wetland species composition. Wetlands that develop alongside the newly carved channel are
likely to be different than the wetlands formerly bordering the impoundment area in terms of
plant and animal species composition.
The biological changes associated with the removal of a dam can be described in phases, as the
waterbody makes the transition from reservoir to river. This includes a pattern of relatively rapid
recovery for invertebrates or short-lived taxa, followed by a second phase of slower recovery for
fish or longer-lived taxa if the dam removal is not an especially large or disruptive event.
Overall, the initial impacts, such as colonization by invasive species, typically determine the
ecological recovery that follows (Doyle et al., 2000).
Dam removal can allow for improved fish passage and unrestricted fish movement that provides
access to spawning habitat upstream. For coastal rivers, the removal of a dam may enable tidal
waters to reach upper portions of the stream that were formerly cut off by the dam, creating a
spawning environment preferred by certain fish species. Access to upstream sections is
particularly beneficial for some anadromous fish that live most of their lives in saltwater and
swim upstream toward freshwater to spawn (Massachusetts River Restore Program, 2002).
A dam can also act as a barrier between upstream and downstream fish populations. If a
downstream community offish is an invasive fish species the dam serves as a physical barrier to
separate the invasives from the upstream community (American Rivers, 2002a). Thus, the
removal of the dam can negatively impact the ecosystem if it allows for the movement of a
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Chapter 2: Background
population of an invasive species that was previously prevented from traveling to a section of the
stream because of the presence of a dam.
Biological Changes: Downstream Impacts
Downstream of the former dam, wetlands are likely to reappear along side the stream channel
where they occurred prior to the construction of the dam (WRM, 2000). Revegetation of river
beds and banks typically occurs within one growing season, following removal of a dam
(Massachusetts River Restore Program, 2002).
Recolonization of the stream banks by vegetation affects the biological community within the
stream by providing shade, reducing water temperatures, and supplying a source of woody debris
and organic matter to the stream.
As streamside vegetation begins to recover and suitable habitat is restored, fish begin to return.
Changes in flow as a result of dam removal lead to the development of side channels and ponds
that provide habitat for fish and wildlife. Increased flow rates also allow for the transport of
larger debris, including gravel and logs, which create spawning beds and pool and riffle habitat
(River Recovery, 2001). In addition, the rocky substrate environment, which is typically exposed
as a result of dam removal, provides habitat for aquatic insects and spawning fish. In the long
term, the return to natural stream temperatures, oxygen levels, and flow rates all contribute to the
reestablishment of a healthy aquatic and riparian ecosystem.
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Chapter 3: Channelization and Channel Modification
Chapter 3: Channelization and Channel Modification
Channelization and channel modification describe river and stream channel engineering
undertaken for flood control, navigation, drainage improvement, and reduction of channel
migration potential. Activities that fall into this category include straightening, widening,
deepening, or relocating existing stream channels and clearing or snagging operations. These
forms of hydromodification typically result in more uniform channel cross-sections, steeper
stream gradients, and reduced average pool depths. Channelization and channel modification
also refer to the excavation of borrow pits, canals, underwater mining, or other practices that
change the depth, width, or location of waterways, or embayments within waterways.
Channelization and channel modification activities can play a critical role in nonpoint source
pollution by increasing the downstream delivery of pollutants and sediment that enter the water.
Some channelization and channel modification activities can also cause higher flows, which
increase the risk of downstream flooding.
Channelization and channel modification can:
• Disturb stream equilibrium
• Disrupt riffle and pool habitats
• Create changes in stream velocities
• Eliminate the function of floods to control channel-forming properties
• Alter the base level of a stream (streambed elevation)
• Increase erosion and sediment load
Many of these impacts are related. For example, straightening a stream channel can increase
stream velocities and destroy downstream pool and riffle habitats. As a result of less structure in
the stream to retard velocities, downstream velocities may continue to increase and lead to more
frequent and severe erosion.
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Chapter 3: Channelization and Channel Modification
Management Measure 1: Physical and Chemical Characteristics of
Channelized or Modified Surface Waters
Management Measure 1
1) Evaluate the potential effects of propose4 channelization an4 channel
moc[ification on the physical an4 chemical characteristics of surface waters.
2) Plan an4 4esign channelization an4 channel mo4ification to re4uce un4esirab>Ie
impacts.
3) Develop an operation an4 maintenance program for existing mo4ifie4 channels
that inclu4es identification an4 implementation of opportunities to improve
physical an4 chemical characteristics of surface waters in those channels.
This management measure applies to proposed channelization or channel modification projects
and is intended to occur concurrently with the implementation of Management Measure 2
(Instream and Riparian Habitat Restoration). The intent of the management measure is for
project planners to consider potential changes in surface water characteristics when evaluating
proposed channelization or channel modification projects. Also, for existing modified channels,
the planning process can include consideration of opportunities to improve the surface water
characteristics necessary to support desired fish and wildlife.
The purpose of the management measure is to ensure that the planning process for new
hydromodification projects addresses changes to physical and chemical characteristics of surface
waters that may occur as a result of proposed work. For existing projects, this management
measure can be used to ensure the operation and maintenance program uses any opportunities
available to improve the physical and chemical characteristics of the surface waters.
Changes created by channelization and channel modification activities are problematic if they
unexpectedly alter environmental parameters to levels outside normal or desired ranges. The
physical and chemical characteristics of surface waters that may be influenced by channelization
and channel modification include sedimentation, turbidity, salinity, temperature, nutrients,
dissolved oxygen, oxygen demand, and contaminants. Changes in natural sediment supplies,
reduced freshwater availability, and accelerated delivery of pollutants are examples of the types
of changes that can be associated with channelization and channel modification.
Published case studies of existing channelization and channel modification projects describe
alterations to physical and chemical characteristics of surface waters (Burch et al., 1984;
Petersen, 1990; Reiser et al., 1985; Roy and Messier, 1989; Sandheinrich and Atchison, 1986;
Sherwood et al., 1990; Shields et al., 1995). Frequently, the post-project conditions are
intolerable to desirable fish and wildlife. The literature also describes instream benefits for fish
and wildlife that can result from careful planning of channelization and channel modification
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Chapter 3: Channelization and Channel Modification
projects (Bowie, 1981; Los Angeles River Watershed, 1973; Sandheinrich and Atchison, 1986;
Shields et al., 1990; Swanson et al., 1987; USAGE, 1989).
Management Practices for Management Measure 1
Implementation of this management measure should begin during the planning process for new
projects. For existing projects, implementation of this management measure can be included as
part of a regular operation and maintenance program. The approach is two-pronged and should
include:
1. Planning and evaluation, with numerical models for some situations, of the types of
nonpoint source (NFS) pollution related to instream changes and watershed development.
2. Operation and maintenance programs that apply a combination of nonstructural and
structural practices to address some types of NFS problems stemming from instream
changes or watershed development.
Use models/methodologies as one
means to evaluate the effects of
proposed channelization and channel
modification projects on the physical and
chemical characteristics of surface
waters. Evaluate these effects as part of
watershed plans, land use plans, and
new development plans.
Planning and Evaluation
In planning-level evaluations of proposed
hydromodification projects, it is critical to
understand that the surface water quality and
ecological impact of the proposed project will be
driven primarily by the alteration of physical
transport processes. In addition, it is critical to
realize that the most important environmental
consequences of many hydromodification projects
will occur over a long-term time scale of years to decades.
The key element in the selection and application of models for the evaluation of the
environmental consequences of hydromodification projects is the use of appropriate models to
adequately characterize circulation and physical transport processes. Appropriate surface water
quality and ecosystem models (e.g., salinity, sediment, cultural eutrophication, oxygen, bacteria,
fisheries, etc.) are then selected for linkage with the transport model to evaluate the
environmental impact of the proposed hydromodification project. There are several sophisticated
two-dimensional (2D) and three-dimensional (3D) time-variable hydrodynamic models available
for environmental assessments of hydromodification projects. Two-dimensional depth or
laterally averaged hydrodynamic models can be routinely applied to assist with environmental
assessments of beneficial and adverse effects on surface water quality by knowledgeable teams
of physical scientists and engineers (Hamilton, 1990). Three-dimensional hydrodynamic models
are also beginning to be more widely applied for large-scale environmental assessments of
aquatic ecosystems (e.g., EPA/USACE-WES Chesapeake Bay 3D hydrodynamic and surface
water quality model).
Refer to Chapter 8 for a list of some models available for studying the effects of channelization
and channel modification activities (Table 8.1). Chapter 8 also provides examples of
channelization and channel modification activities and associated models that can be used in the
planning process.
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Chapter 3: Channelization and Channel Modification
Operation and Maintenance Programs
Several management practices can be implemented to avoid or mitigate the physical and
chemical impacts generated by hydromodification projects. Many of these practices have been
engineered and used for several decades, not only to mitigate human-induced impacts but also to
rehabilitate hydrologic systems degraded by natural processes.
In cases where existing channelization or channel modification projects can be changed to
enhance instream or streamside characteristics, several practices can be included as a part of
regular operation and maintenance programs. New channelization and channel modification
projects that are predicted to cause unavoidable physical or chemical changes in surface waters
can also use one or more practices to mitigate the undesirable changes. Some of the types of
practices include:
• Grade control structures
• Levees, setback levees, and floodwalls
• Noneroding roadways
• Streambank protection and instream sediment load controls
• Vegetative cover
Grade Control Structures
There are two basic types of grade control structures. The first type can be referred to as a bed
control structure because it is designed to provide a hard point in the streambed that is capable of
resisting the erosive forces of the degradational zone. The second type can be referred to as a
hydraulic control structure because it is designed to function by reducing the energy slope along
the degradational zone to the point where the stream is no longer capable of scouring the bed.
The distinction between the operating processes of these two types is important whenever grade
control structures are considered (Biedenharn and Hubbard, 2001).
Design considerations for siting of grade control structures include determining the type,
location, and spacing of structures along the stream, along with the elevation and dimensions of
structures. Siting grade control structures can be considered a simple optimization of hydraulics
and economics. However, these factors alone are usually not sufficient to define optimum siting
conditions. Hydraulic considerations must be integrated with a host of other factors that can vary
from site to site to determine the final structure plan. Some of the more important factors to be
considered when siting grade control structures are discussed more specifically in the U.S. Army
Corps of Engineers' Design Consideration for Siting Grade Control Structures (Biedenharn and
Hubbard, 2001).
When carefully applied, grade control structures can be highly versatile in establishing human
and environmental benefits in stabilized channels. To be successful, application of grade control
structures should be guided by analysis of the stream system both upstream and downstream
from the area to be reclaimed (CASQA, 2003).
In some cases, grade control structures can be designed to allow fish passage. However, some
grade control structures can obstruct fish passage. In many instances, fish passage is a primary
consideration and may lead engineers to select several small fish passable structures in lieu of
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Chapter 3: Channelization and Channel Modification
one or more high drops that would restrict fish passage. In some cases, particularly when drop
heights are small, fish are able to migrate upstream past a structure during high flows. In
situations where structures are impassable, and where the migration offish is an important
concern, openings, fish ladders, or other passageways must be incorporated into the structure's
design (Biedenharn and Hubbard, 2001). Fish passage practices are described in Chapter 7.
A type of grade control structure is a check dam. Refer to Chapter 7 for more information about
this practice.
Levees. Setback Levees, and Floodwalls
Levees are embankments or shaped mounds constructed for flood control or hurricane protection
(USAGE, 1981). Setback levees and floodwalls are longitudinal structures used to reduce
flooding and minimize sedimentation problems associated with fluvial systems. These practices
can be used to reduce the impacts of channelization and channel modification. A more detailed
discussion of levees, setback levees, and floodwalls is available in Chapter 7.
Noneroding Roadways
Disturbances along the streambank that result from activities associated with operation and
maintenance of channelization projects can lead to additional nonpoint source pollution impacts
to the stream. An example of human-induced activities is erosion associated with roadways.
Rural road construction, streamside vehicle operation, and stream crossings usually result in
significant soil disturbance and create a high potential for increased erosion processes and
sediment transport to adjacent streams and surface waters. Erosion during and after construction
of roadways can contribute large amounts of sediment and silt to runoff waters, which can
deteriorate water quality and lead to fish kills and other ecological problems (USEPA, 1995b).
Road construction involves activities such as clearing of existing native vegetation along the
road right-of-way; excavating and filling the roadbed to the desired grade; installation of culverts
and other drainage systems; and installation, compaction, and surfacing of the roadbed.
Although most erosion from roadways occurs during the first few years after construction,
significant impacts may result from maintenance operations using heavy equipment, especially
when the road is located adjacent to a waterbody. In addition, improper construction and lack of
maintenance may increase erosion processes and the risk for road failure. To minimize erosion
and prevent sedimentation impacts on nearby waterbodies during construction and operation
periods, streamside roadway management needs to combine proper design for site-specific
conditions with appropriate maintenance practices. A discussion of how roadways can impact
fish habitat and passage is available from EPA''s National Management Measures to Control
Nonpoint Source Pollution from Forestry (USEPA, 2005a).
More information about suggested practices to consider during design, construction, operation
and maintenance, and general maintenance of noneroding roadways, is available from EPA's
National Management Measures to Control Nonpoint Source Pollution from Forestry (USEPA,
2005a). This EPA guidance document also provides some suggested permanent control BMPs
that may be used to prevent erosion from roadways. Additional information about noneroding
roadways is available in Chapter 7 and the Resources section of this document.
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Chapter 3: Channelization and Channel Modification
Streambank Protection and Instream Sediment Load Controls
Streambank erosion is a natural process that occurs in fluvial systems. Streambank erosion can
also be induced or exaggerated as a result of human activities. There are several factors within a
watershed that can contribute to human induced Streambank erosion. Accelerated Streambank
erosion related to human activity can typically be attributed to three major causes including
channel modifications, reservoir construction, and land use changes (Henderson, 1986). When
possible, Streambank erosion problems should be addressed in the context of the entire
watershed, using a systems approach that considers and accommodates natural stream processes.
Approaches to addressing Streambank erosion problems associated with channelization and
channel modification activities can involve efforts to identify and address all significant
contributing factors in addition to treating the immediate symptom, bank erosion.
In general, the design of Streambank protection may involve the use of several techniques and
materials. Nonstructural or programmatic management practices for the prevention of
Streambank failures include:
• Protection of existing vegetation along streambanks
• Careful use or regulation of irrigation near streambanks, such as rerouting of overbank
drainage
• Minimization of loads on top of streambanks (such as prevention of building within a
defined distance from the streambed)
Several structural practices are used to protect or rehabilitate eroded banks. These practices are
usually implemented in combination to provide stability of the stream system, and they can be
grouped into direct and indirect methods. Direct methods place protecting material in contact
with the bank to shield it from erosion. Indirect methods function by deflecting channel flows
away from the bank or by reducing the flow velocities to nonerosive levels (Henderson, 1986;
Henderson and Shields, 1984). Indirect bank protection requires less bank grading and tree and
snag removal. However, some structural methods like stone toe protection, as discussed below,
can be placed with minimal disturbance to existing slope, habitat, and vegetation.
Feasibility of the practices at a site depends on the engineering design of the structure,
availability of the protecting material, extent of the bank erosion, and specific site conditions
such as the flow velocity, channel depth, inundation characteristics, and geotechnical
characteristics of the bank. The use of vegetation alone or in combination with other structural
practices, when appropriate, could further reduce the engineering and maintenance efforts.
Vegetation can be considered with respect to site-specific characteristics. When vegetation is
combined with low cost building materials or engineered structures, numerous techniques can be
created for Streambank erosion control. It is important to consider the assets and limitations when
planning to use planted vegetation for Streambank protection. Advantages of vegetation include
the following (Allen and Leech, 1997):
• Reinforces soil (increases bank stability).
• Increases resistance to flow and reduces flow velocities (from exposed stalks), causing
the flow to dissipate energy against the plant (rather than the soil).
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Chapter 3: Channelization and Channel Modification
• Intercepts water.
• Enhances water infiltration.
• Depletes soil water by uptake and transpiration.
• Acts as a buffer against the abrasive effect of transported materials.
• Induces sediment deposition (from close-growing vegetation).
• Reduces costs, in some cases, when compared to most structural methods.
• Improves conditions for fisheries and wildlife.
• Improves water quality.
• Protects cultural/archeological resources.
Limits of vegetation include failure to grow; being subject to undermining; being uprooted by
wind, water, and the freezing and thawing of ice; ingestion by wildlife or livestock; and
maintenance requirements. Chapter 3 ofBioengineeringfor Streambank Erosion Control
discusses plant acquisition, handling, and timing of planting (Allen and Leech, 1997).
Streambanks can be protected or restored either by increasing resistance of the bank to erosion or
by decreasing the energy of the water at the point of contact with the bank, for example by
deflecting or interrupting flows (Henderson, 1986). Instream sediment can be controlled by using
several structural, vegetative, or bioengineered practices, depending on the management
objective and the source of sediment. Streambank protection and channel stabilization practices,
including various types of revetments, grade control structures, and flow restrictors, have been
effective in controlling sediment production caused by Streambank erosion. Designs should
match the protection capability of the treatment to the erosion potential of each stream zone. For
example, riprap may be needed at the toe of a slope to protect it from undercutting combined
with tree revetments to deflect flows and provide protection for live stakings that will develop
permanent support. The growing body of research indicates management techniques that emulate
nature and work with natural stream processes are more successful and economical.
Significant amounts of instream sediment deposition can be prevented by controlling bank
erosion processes and streambed degradation. Channel stabilization structures can also be
designed to trap sediment and decrease the sediment delivery to desired areas by altering the
transport capacity of the stream and creating sediment storage areas. In regulated streams,
alteration of the natural streamflow, particularly the damping of peak flows caused by surface
water regulation and diversion projects, can increase streambed sediment deposits by impairing
the stream's transport capacity and its natural flushing power. Sediment deposits and reduced
flow alter the channel morphology and stability, the flow area, the channel alignment and
sinuosity, and the riffle and pool sequence. Such alterations have direct impacts on the aquatic
habitat and the fish populations in the altered streams (Reiser et al., 1985).
Vegetative Cover
Streambank protection using vegetation is a commonly used practice, particularly in areas of low
water velocities. Vegetative cover, also used in combination with structural practices, is often
relatively easy to establish and maintain, and is visually attractive (USAGE, 1983). Emergent
vegetation provides two levels of protection. First, the root system helps hold soil together and
increases overall bank stability by forming a binding network. Second, the exposed stalks, stems,
branches, and foliage provide resistance to streamflow, causing the flow to lose part of its energy
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Chapter 3: Channelization and Channel Modification
by deforming the plants rather than by removing the soil particles. Above the waterline,
vegetation protects against rainfall impact on the banks and reduces the velocity of the overland
flow during storm events.
Vegetative controls are not suitable for all sites, especially those sites with severe erosion due to
high flow rates or channel velocities. Refer to the Washington State Department of
Transportation's (WSDOT's) Hydraulics Manual, Chapter 41 for information on calculating
flow rates or channel velocities. Stabilization measures should only be implemented after a
careful evaluation of the stream and the surrounding area. A knowledgeable fluvial
geomorphologist may be helpful with this evaluation. In addition, plant species should be
selected with care; native plant species should be used whenever possible. Appropriate species
can be determined by consulting horticulturalists and botanists for plant selection assistance. The
USDA-Forest Service guide, A Soil Bioengineering Guide for Streambank andLakeshore
Stabilization provides a list of plants for soil bioengineering associated systems. The
International Erosion Control Association (IECA)3 publishes a products and services directory
listing sources of plant material and professional assistance.
In addition to bank stabilization, vegetation can also offer pollutant filtering capacity. Pollutants
and sediment transported by overland flow may be partly removed as a result of a combination of
processes including reduction in flow pattern and transport capacity, settling and deposition of
particulates, and eventual nutrient uptake by plants.
Summary of Physical and Chemical Practices
All of the following practices can be used to address the effects of channelization and channel
modification activities on the physical and chemical characteristics of a waterbody:
• Bank shaping and planting
• Branch packing
• Brush layering
• Brush mattressing
• Bulkheads and seawalls
• Check dams
• Coconut fiber roll
• Dormant post plantings
• Erosion and Sediment Control (ESC) Plans
• Joint plantings
• Levees, setback levees, and floodwalls
• Live crib walls
• Live fascines
• Live staking
• Noneroding roadways
• Return walls
1 http://www.wsdot.wa.gov/eesc/design/hvdraulics/Manual/Rev3Publications/Chapter%204.pdf
2 http://www.fs.fed.us/publications/soil-bio-guide
3 http://ieca.org
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Chapter 3: Channelization and Channel Modification
• Revetments
• Riprap
• Root wad revetments
• Rosgen's Stream Classification Method
• Setbacks
• Toe protection
• Tree revetments
• Vegetated buffers
• Vegetated gabions
• Vegetated geogrids
• Vegetated reinforced soil slope (VRSS)
• Wing deflectors
Additional information about each of the above practices is available in Chapter 7. The
Additional Resources section provides a number of sources for obtaining information about the
effectiveness, limitations, and cost estimates for these practices.
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Chapter 3: Channelization and Channel Modification
Management Measure 2: Instream and Riparian Habitat
Restoration
Management Measure 2
1) Evaluate the potential effects of propose4 channelization an4 channel
moc[ification on instream an4 riparian habitat.
2) Plan an4 4esign channelization an4 channel mo4ification to re4uce un4esirable
impacts.
3) Develop an operation an4 maintenance program for existing mo4ifie4 channels
that inclu4es identification an4 implementation of opportunities to restore
instream an4 riparian habitat in those channels.
Implementation of this management measure is intended to occur concurrently with the
implementation of the Management Measure for Physical and Chemical Characteristics of
Channelized or Modified Surface Waters (see previous management measure discussion). This
management measure pertains to surface waters where channelization and channel modification
have altered or have the potential to alter instream and riparian habitat, such that historically
present plants, fish, or wildlife are adversely affected. This management measure is intended to
apply to any proposed channelization or channel modification project to determine changes in
instream and riparian habitat and to existing modified channels to evaluate possible
improvements to instream and riparian habitat. The purpose of this management measure is to
correct or prevent detrimental changes to instream and riparian habitat from the impacts of
channelization and channel modification projects.
Management Practices for Management Measure 2
Implementation of this management measure should begin during the planning process for new
projects. For existing projects, implementation of this management measure can be included as
part of a regular operation and maintenance program. Ensuring the involvement and participation
of all partners is a place to start on any restoration project. Determining the extent of the
restoration activity can help identify potential partners and other interested stakeholders. Each
stakeholder may bring a certain expertise, historical information and data, and possibly funding
to a project. Development of a stream corridor restoration plan can help organize the group, set
goals for implementation of management practices, secure funding or other types of support, and
facilitate the sharing of ideas and accomplishments within the group and to others in the
community. The approach is two-pronged and should include:
1. Planning and evaluation, with numerical models for some situations, of the types of NFS
pollution related to instream and riparian habitat changes and watershed development.
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Chapter 3: Channelization and Channel Modification
2. Operation and maintenance activities that restore habitat through the application of a
combination of nonstructural and structural practices to address some types of NFS
problems stemming from instream and riparian habitat changes or watershed
development.
Planning and Evaluation
Several tools can be used to evaluate the instream and riparian health of a stream system. These
approaches include:
• Biological methods/models
• Temperature restoration practices
• Geomorphic assessment techniques
• Expert judgment and checklists
Biological Methods/Models
To assess the biological impacts of channelization, it is
necessary to evaluate both physical and biological
attributes of the stream system. Assessment studies
should be performed before and after channel
modification, with samples being collected upstream
from, within, and downstream from the modified reach to
allow characterization of baseline conditions. It also may
be desirable to identify and sample a reference site within
the same ecoregion as part of the rapid bioassessment procedures discussed below.
Use models/methodologies to
evaluate the effects of proposed
channelization and channel
modification projects on instream
and riparian habitat and to determine
the effects after such projects are
implemented.
There are a number of different methods that can be used to assess the biological impacts of
channelization. Rapid Bioassessment Protocols (RBPs) were developed as inexpensive screening
tools for determining whether a stream is supporting a designated aquatic life use (Barbour et al.,
1999; Plafkin et al., 1989). One component of these protocols is an instream habitat assessment
procedure that measures physical characteristics of the stream reach (Barbour and Stribling,
1991). An assessment of instream habitat quality based on 12 instream habitat parameters is
performed in comparison to conditions at a "reference" site, which represents the "best
attainable" instream habitat in nearby streams similar to the one being studied. The RBP habitat
assessment procedure has been used in a number of locations across the United States. A small
field crew of one or two persons typically can perform the procedure in approximately 20
minutes per sampling site.
Rapid Bioassessment Protocols (Barbour et al., 1999; Plafkin et al., 1989) were designed to be
scientifically valid and cost-effective and to offer rapid return of results and assessments.
Protocol III (RBP III) focuses on quantitative sampling of benthic macroinvertebrates in
riffle/run habitats or on other submerged, fixed structures (e.g., boulders, logs, bridge abutments,
etc.) where such riffles may not be available. The data collected are used to calculate various
metrics pertaining to benthic community structure, community balance, and functional feeding
groups. The metrics are assigned scores and compared to biological conditions as described by
either an ecoregional reference database or reference sites chosen to represent the "best
attainable" biological community in similarly sized streams. In conjunction with the instream
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Chapter 3: Channelization and Channel Modification
habitat quality assessment, an overall assessment of the biological and instream habitat quality at
the site is derived. RBP III can be used to determine spatial and temporal differences in the
modified stream reach. Application of RBP III requires a crew of two persons; field collections
and lab processing require 4 to 7 hours per station and data analysis about 3 to 5 hours, totaling 7
to 12 hours per station. The RBP III has been extensively applied across the United States. More
information about biological assessments is available from EPA's Biological Assessment Web
site.4
Karr et al. (1986) describes an Index of Biological Integrity (IBI), which includes 12 metrics in
three major categories offish assemblage attributes: species composition, trophic composition,
and fish abundance and condition. Data are collected at each site and compared to those collected
at regional reference sites with relatively unimpacted biological conditions. A numerical rating is
assigned to each metric based on its degree of agreement with expectations of biological
condition provided by the reference sites. The sum of the metric ratings yields an overall score
for the site. Application of the IBI requires a crew of two persons; field collections require 2 to
15 hours per station and data analysis about 1 to 2 hours, totaling 3 to 17 hours per station. The
IBI, which was originally developed for Midwestern streams, can be readily adapted for use in
other regions. It has been used in several states across the country to assess a wide range of
impacts in streams and rivers.
Habitat Evaluation Procedures (HEPs) can be used to document the quality and quantity of
available habitat, including aquatic habitat, for selected wildlife species. HEPs provide
information for two general types of instream and riparian habitat comparisons:
• The relative value of different areas at the same point in time
• The relative value of the same area at future points in time
By combining the two types of comparisons, the impact of proposed or anticipated land and
water use changes on instream and riparian habitat can be quantified (Ashley and Berger, 1997).
Additional information about the assessment methods discussed above, as well as other methods
for assessing biological impacts is available in Table 8.2 of Chapter 8.
Temperature Restoration Practices
Channelization and channel modification activities can greatly impact stream temperature. All
other factors remaining unchanged, when a channel is narrowed, the water depth increases and
the surface area exposed to solar radiation and ambient temperature decreases. This can decrease
water temperature. When a channel is widened, the opposite occurs; shallower depths and
increased temperatures occur. Temperature may also be increased from increased turbidity
because the sediment particles absorb heat. It is important to model how temperature will change
in a stream, as a result of channelization and channel modification activities, to determine what
other changes and impacts might occur in the stream.
1 http://www.epa.gov/owow/monitoring/bioassess.html
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Chapter 3: Channelization and Channel Modification
Stream temperature has been widely studied, and heat transfer is one of the better-understood
processes in natural watershed systems. Most available approaches use energy balance
formulations based on the physical processes of heat transfer to describe and predict changes in
stream temperature.
More information about temperature restoration models and practices is provided in Chapter 8
(Modeling).
Geomorphic Assessment Techniques
Fluvial geomorphology is the study of stream form and function. Geomorphic assessment
focuses on qualitative and quantitative observations of stream form. It provides a "moment-in-
time" characterization of the existing morphology of the stream. In addition, geomorphic
assessment includes a stability component. Stability assessments place the stream in the context
of past, present, and anticipated adjustment processes. Geomorphic assessments can be useful in
predicting changes that could be created by channelization and channel modification activities.
Stream classification is a technique that is used to show the relationship between streams and
their watersheds. There are several techniques for stream classification, all of which have
advantages and limitations. Advantages of geomorphic assessment include (adapted from
FISRWG, 1998):
• Promotes communication.
• Enables extrapolation of data collected on a few streams to a number of channels over a
broader geographical area.
• Helps the restoration practitioner consider the landscape context and determine expected
ranges of parameters.
• Enables practitioners to interpret the channel-forming or dominant processes active at the
site.
• Uses reference reaches as the desired outcome of restoration.
• Provides an important cross-check to verify if the selected design values are within a
reasonable range.
Limitations of geomorphic assessment include (adapted from FISRWG, 1998):
• Determination of bankfull or channel-forming flow depth may be difficult or inaccurate.
• The dynamic condition or the stream is not indicated in stream classification systems.
• River response to a perturbation or restoration action is normally not determined by
classifying it alone.
• Biological health is not directly determined.
• Classifying a stream should not be used alone to determine the type, location, and
purpose of restoration activities.
Schumm (1960) identified straight, meandering, and braided channels and related both channel
pattern and stability to modes of sediment transport. Schumm recognized that stable straight and
meandering channels have mostly suspended sediment loads and cohesive bank materials, as
opposed to unstable braided streams characterized by mostly bedload sediment transport and
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Chapter 3: Channelization and Channel Modification
wide sandy channels with noncohesive bank materials. Meandering mixed-load channels are
found at an intermediate condition (FISRWG, 1998).
Montgomery and Buffington (1993) proposed a classification system similar to Schumm for
alluvial, colluvial, and bedrock streams in the Pacific Northwest. This system addresses channel
response to sediment inputs throughout the drainage network. Six classes of alluvial channels
were identified—cascade, step-pool, plane-bed, riffle-pool, regime, and braided. The stream
types are differentiated based on channel response to sediment inputs. For example, steeper
channels maintain their morphology while transporting sediment. Streams with lower gradients
make more morphological adjustments with increased sediment loads (FISRWG, 1998).
A conceptual model of channel evolution in response to channelization (CEM-channel evolution
model) was developed by Simon and Hupp (1986, 1987), Hupp and Simon (1986, 1991), and
Simon (1989a, 1989b). The model identifies six geomorphic stages of channel response and was
developed and extensively applied to predict empirical stream channel changes following large-
scale channelization projects in western Tennessee. Data required for model application include
bed elevation and gradient, channel top-width, and channel length before, during, and after
modification. Gauging station data can be used to evaluate changes through time of the stage-
discharge relationship and bed-level trends. Riparian vegetation is dated to provide ages of
various geomorphic surfaces and thereby to deduce the temporal stability of a reach.
A component of Simon and Hupp's (1986, 1987) channel response model is the identification of
specific groups of woody plants associated with each of the six geomorphic channel response
stages. Their findings for western Tennessee streams suggest that the site preference or
avoidance patterns of selected tree species allow their use as indicators of specific bank
conditions. This method might require calibration for specific regions of the United States to
account for differences in riparian zone plant communities, but it would allow simple vegetative
reconnaissance of an area to be used for a preliminary estimate of stream recovery stage (Simon
and Hupp, 1987).
Restoring or maintaining streams to a stable form through natural channel design requires
detailed information about surface water hydrology and the interactions between rainfall and
overland flow or runoff. The Rosgen classification system, developed by David L. Rosgen, and
presented in Applied River Morphology., is currently the most comprehensive and widely used
quantitative assessment method for geomorphology. It represents a compilation of much of the
early work in applied fluvial geomorphology and relies largely on the identification of bankfull
field indicators. The bankfull discharge is the flow event that fills a stable alluvial channel up to
the elevation of the active floodplain (Rosgen, 1996). Dunne and Leopold (1978) first developed
hydraulic geometry relationships for the bankfull stage, also called regional curves. Most river
engineers and hydrologists work under the assumption that the bankfull discharge is equivalent
to the channel forming or dominant discharge in geomorphic classification and in analog and
empirical design methods. The bankfull discharge is the only discharge that can be easily
identified in the field using physical indicators; therefore it is one of the most commonly used in
natural channel design. Additional information about Rosgen is available in Chapter 7.
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Chapter 3: Channelization and Channel Modification
Moment-in-time stream classifications provide insights into the existing form of the stream and
can help to define design parameters and understand potential modifications in reference to
existing conditions. Stream classification offers a way to categorize streams based on channel
morphology. The older classification systems were largely qualitative descriptions of stream
features and landforms and were difficult to apply universally. In 1994, Rosgen published^
Classification of Natural Rivers. Because of its relative simplicity and usefulness in stream
restoration, the Rosgen classification system has become popular among hydrologists, engineers,
geomorphologists, and biologists working to restore the biological function and stability of
degraded streams. The classification consists of 41 major stream types for which stream channel
stability and stream bank erosion potential can be assessed. From the assessment, structures for
in-stream and stream bank restoration or modification can be selected. When planning stream
restoration projects, it is important for the planning team to use a multidisciplinary approach that
includes consideration of hydraulics, hydrology, water quality, geomorphological processes, and
biological interactions to develop and implement a successful restoration. Chapter 7 provides
additional detailed information on stream classification practices.
In site selection, geomorphic assessments can determine if a site is unstable and in need of some
form of restoration activity. During design, geomorphic assessments can be used in combination
with hydrologic, hydraulic, and/or sediment transport analyses to define design elements such as
channel slope and hydraulic geometry.
Sediment transport analysis in rivers and streams is used to approximate the amount of sediment
being moved by flow event scenarios and to determine where it will be deposited. Modeling the
sediment transport capacity of a channel and its predicted sediment deposition patterns are
important for assessing existing and proposed channel design projects to estimate potential
project impacts. Sediment transport analysis is also useful for determining restoration
opportunities in existing channelization and channel modification projects. Sediment transport
analysis is often coupled with stable channel analyses methods to refine channel geometries to
estimate optimal scour and deposition characteristics (Schulte et al., 2000). A good source of
technical information on sediment transport analysis can be found in River Engineering for
Highway Encroachments (FHWA, 2001).
Sediment transport analysis has been used in many projects, including:
• Channel design projects (Schulte et al., 2000)
• Stream restoration design (Copeland et al., 2001; Shields et al., 2003)
• Flood control projects (USACE, 1994)
• Highway projects that include stream crossings (FHWA, 2001)
In the design of new channelization projects and analysis of existing projects, channels are
typically evaluated using channel stability methods and then the analysis is refined using
sediment transport models. Sediment transport analysis is used to refine geometry so that scour
and deposition are minimized. It is also used to determine the optimum grade control structure
elevation and placement and to find the excavation depths in depositional zones to minimize
operational costs for maintaining the channel geometry (Schulte et al., 2000).
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Chapter 3: Channelization and Channel Modification
The methods and techniques used to accomplish a geomorphic assessment should be project-
specific and conducted by personnel trained in applied fluvial geomorphology. Geomorphic
assessment of streams has evolved rapidly over the past 10-15 years. Initial methodologies
tended to be tailored for localized applications and required extensive data collection and
validation. Rosgen's methodology provides a more universal approach to stream classification
that represents trade-offs between data collection needs and ease of application for many
different stream types. The challenge to this type of modeling and assessment has always been to
balance the complexity and need for extensive data collection with ease of use and reliability of
the results. The key is that the geomorphic assessment must provide a fundamental
understanding of the linkage between river form and process. The assessment should provide
insight into where the stream has been, is now, and in what direction it is moving. It should also
place the project reach in the context of broader system wide adjustment processes. Geomorphic
assessment can be used to select sites for restoration and develop designs.
Expert Judgment and Checklists
Approaches using expert judgment and checklists developed based on experience acquired in
previous projects and case studies may be very helpful in integrating environmental goals into
project development. The USAGE used this concept of incorporating environmental goals into
project design (Shields and Schaefer, 1990) in the development of a computer-based system for
the environmental design of waterways (ENDOW). The ENDOW system is composed of three
modules: a streambank protection module, a flood control channel module, and a streamside
levee module. The three modules require the definition of the pertinent environmental goals to be
considered in the identification of design features. Depending on the environmental goals
selected for each module, ENDOW will display a list of comments or cautions about anticipated
impacts and other precautions to be taken into account in the design.
Another example of using expert judgment is the Proper Functioning Condition (PFC) technique.
PFC was developed by the Bureau of Land Management (BLM) to rapidly assess whether a
stream riparian area is functioning properly in terms of hydrology, landform/soils, channel
characteristics, and vegetation. The assessment is performed by an interdisciplinary team and
involves completing a checklist evaluating 17 factors concerning hydrology, vegetation, and
erosional/depositional characteristics. The PFC field technique is not quantitative, but with
adequate training, results are reproducible to a high degree (FISRWG, 1998).
Operation and Maintenance Activities
Implementation practices for instream and riparian habitat restoration in planned or existing
modified channels are consistent with those management practices for physical and chemical
characteristics of channelized or modified surface waters. To prevent future impacts to instream
or riparian habitat or to solve current problems caused by channelization or channel modification
projects, include one or more of the following practices to mitigate the undesirable changes:
• Bank shaping and planting
• Branch packing
• Brush layering
• Brush mattressing
• Bulkheads and seawalls
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Chapter 3: Channelization and Channel Modification
• Check dams
• Coconut fiber roll
• Dormant post plantings
• Erosion and Sediment Control (ESC) Plans
• Establish and protect stream buffers
• Joint plantings
• Levees, setback levees, and floodwalls
• Live crib walls
• Live fascines
• Live staking
• Marsh creation and restoration
• Noneroding roadways
• Return walls
• Revetments
• Riparian improvements
• Riprap
• Root wad revetments
• Rosgen's Stream Classification Method
• Setbacks
• Toe protection
• Tree revetments
• Vegetated buffers
• Vegetated gabions
• Vegetated geogrids
• Vegetated reinforced soil slope (VRSS)
• Wing deflectors
Additional information about each of the above practices is available in Chapter 7. The
Additional Resources section provides a number of sources for obtaining information about the
effectiveness, limitations, and cost estimates for these practices.
Operation and maintenance programs should weigh the benefits of including practices such as
those for mitigating any current or future impairments to instream or riparian habitat. Additional
information about these practices can be found in Chapter 7. Also, Fischenich and Allen (2000)
provide a comprehensive summary of practices that can be evaluated for use in operation and
maintenance programs.
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Chapter 4: Dams
Chapter 4: Dams
Dams are a common form of hydromodification. The National Research Council estimated that
there were more than 2.5 million dams in the United States in 1992 (NRC, 1992). These dams
range in size from berms across small streams that create farm ponds to large concrete structures
across major rivers for hydropower and flood control. The USAGE estimates (of these 2.5
million dams in the United States) about 79,000 are large enough to be included in the National
Inventory of Dams (USAGE, n.d.b.).1
Dams generally were built to store and provide water for mechanical power generation (e.g.,
waterwheels to mill grain), industrial cooling, hydroelectric power generation, agricultural
irrigation, municipal water supplies for human consumption, and impoundment-based recreation
(e.g., boating and sport fishing). Dams are also used for flood control and to maintain channel
depths for barge transportation.
Dams can be associated with a number of effects, including changes to hydrology, water quality,
habitat, and river morphology. Lakes and reservoirs integrate many processes that take place in
their contributing watersheds, including processes that contribute energy (heat), sediment,
nutrients, and toxic substances. Human activities, such as agricultural and urban land use,
contribute to contaminant and sediment loads to reservoirs. The presence and operation of dams
can determine the fate of these pollutants in a reservoir or impoundment and potentially
downstream as water is released from the dam. For example, the presence of a dam may lead to
sediment accumulation in a reservoir. However, there are management practices that can mitigate
this integrative effect of a reservoir. One example is selective withdrawals, which are an
operational technique that can be used by some dam operators to provide water quality and
temperatures necessary to sustain downstream fish populations.
When dams are built, depending on size and design, they may alter the river system structure,
causing it to change from a river (flowing) to lake (static) and back to a river (flowing) system.
1 With the National Dam Inspection Act (P.L. 92-367) of 1972, Congress authorized the U.S. Army Corps of
Engineers (USACE) to inventory U.S. dams. The Water Resources Development Act of 1986 (P.L 99-662)
authorized USACE to maintain and periodically publish an updated National Inventory of Dams (NID).
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Chapter 4: Dams
Dams with large storage capacities will, by design, retain water longer than those with little
storage. This can change system flow patterns, which can affect water quality and habitat
upstream and downstream of the dam. Most effects from dams are observed downstream. Table
4.1 provides a description of several common types of dams.
Table 4.1 Types of Dams (FEMA, 2003)
Type of Dam
Ambursen dam
Arch dam
Buttress dam
Crib dam
Diversion dam
Double curvature
arch dam
Earth dam
Embankment dam
Gravity dam
Hollow gravity dam
Hydraulic fill dam
Industrial waste
dam
Masonry dam
Mine tailings dam
(or tailings dam)
Multiple arch dam
Overflow dam
Regulating dam
(or afterbay dam)
Rock-fill dam
Roller compacted
concrete dam
Rubble dam
Saddle dam (or
dike)
Description
A buttress dam in which the upstream part is a relatively thin, flat slab usually
made of reinforced concrete
A concrete, masonry, or timber dam with the alignment curved upstream so as
to transmit the major part of the water load to the abutments
A dam consisting of a watertight part supported at intervals on the downstream
side by a series of buttresses
A gravity dam built up of boxes, crossed timbers, or gabions, filled with earth or
rock
A dam built to divert water from a waterway or stream into a different
watercourse
An arch dam that is curved both vertically and horizontally
An embankment dam in which more than 50% of the total volume is formed of
compacted earth layers that are generally smaller than 3-inch size
Any dam constructed of excavated natural materials, such as both earthfill and
rockfill dams, or of industrial waste materials, such as a tailings dam
A dam constructed of concrete and/or masonry, which relies on its weight and
internal strength for stability
A dam constructed of concrete and/or masonry on the outside but having a
hollow interior and relying on its weight for stability
An earth dam constructed of materials, often dredged, which are conveyed and
placed by suspension in flowing water
An embankment dam, usually built in stages, to create storage for the disposal
of waste products from an industrial process
Any dam constructed mainly of stone, brick, or concrete blocks pointed with
mortar
An industrial waste dam in which the waste materials come from mining
operations or mineral processing
A buttress dam comprised of a series of arches for the upstream face
A dam designed to be overtopped
A dam impounding a reservoir from which water is released to regulate the flow
downstream
An embankment dam in which more than 50% of the total volume is comprised
of compacted or dumped cobbles, boulders, rock fragments, or quarried rock
generally larger than 3-inch size
A concrete gravity dam constructed by the use of a dry mix concrete transported
by conventional construction equipment and compacted by rolling, usually with
vibratory rollers
A stone masonry dam in which the stones are unshaped or uncoursed
A subsidiary dam of any type constructed across a saddle or low point on the
perimeter of a reservoir
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Chapter 4: Dams
Siting, construction, operation, maintenance, and removal of dams can lead to nonpoint source
(NFS) effects. For example, siting of dams can result in inundation of wetlands, riparian areas,
and fastland in areas upstream of the dam. During construction or maintenance, erosion and soil
loss occurs. Proper siting and design help prevent erosion prone areas from being developed. For
dams actively controlled by human operators, dam operation and the amount of water released
can affect downstream areas when flood waters necessary to deliver sediment are restricted, or
when controlled releases from dams change the timing, quantity, or quality of downstream flow.
While removal of dams can lead to physical and biological impacts, such as temporary increased
turbidity from redistribution of sediment previously stored behind the dam or displacement of
warm-water species that prefer lake-like conditions, dam removal has many biological and
habitat benefits, such as allowing for easier fish movement and a return of natural stream
temperatures and dissolved oxygen. Sometimes, however, dams limit passage of undesirable
invasive species. Therefore, a comprehensive evaluation of the benefits and limitations resulting
from the presence of a dam should be completed when evaluating operation and maintenance
procedures, as well as options for removal. A more detailed discussion of water quality,
biological, habitat, physical, and chemical changes from dam removal is provided in Chapter 2.
One opportunity to evaluate and address the NFS impacts of some larger dams that are used for
hydropower occurs during the licensing/relicensing process. The Federal Power Act (FPA)
requires all nonfederal hydropower projects located on navigable waters to be licensed. The FPA
(16 U.S.C. 791-828c) was originally enacted as the Federal Water Power Act in 1920 and was
made part of the FPA in 1935. The Federal Energy Regulatory Commission (FERC) is the
independent regulatory agency within the Department of Energy that has exclusive authority,
under the FPA, to license such projects. The hydropower dam relicensing process offers an
opportunity to assess the balance between natural resources and the generation of electricity and
to address some areas that are determined to be problematic. Stakeholders, including dam owners
and operators, local governments, environmental groups, and the public, often have different
interests to be balanced. Through the FPA and the relicensing process, these varied interests can
be evaluated and a balanced outcome can be derived. In conjunction with FPA licensing
requirements, states and authorized tribes certify that discharges (including those that originate
from dams) meet water quality standards under section 401 of the Clean Water Act (CWA).
The FPA also requires relicensing to be conducted in light of recent laws and regulations that are
in effect at the time of renewal. As regulations related to hydropower dams change, it is possible
that many dams that were previously licensed and are up for relicensing may no longer be in
compliance with current regulatory standards. For example, many dams were built prior to the
CWA, which includes regulatory requirements for protecting and maintaining designated uses
(such as protecting desired aquatic life or maintaining bacterial water quality that is protective of
human health for all recreational activities). Other regulatory requirements that may be evaluated
during relicensing include protections for wetlands, aquatic habitat, and endangered species.2
2 Additional information about FERC and hydropower licensing/relicensing is available at http://www.ferc.gov.
EPA841-B-07-002 4.3 July 2007
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Chapter 4: Dams
Management Measure 3: Erosion and Sediment Control for the
Construction of New Dams and Maintenance of Existing Dams
Management Measure 3
1) Rec[uce erosion an4, "to the extent practicable, retain se4iment onsite 4uring an4
after construction.
2) Prior to Ian4 4isturbance, prepare an4 implement an approve4 erosion an4
se4iment control plan or similar a4ministrative 4ocumentthat contains erosion
an4 se4iment control provisions.
The purpose of this management measure is to prevent sediment from entering surface waters
during the construction or maintenance of dams. This management measure emphasizes the
importance of minimizing sediment loss to surface waters during both dam construction and
maintenance. It is essential that proper erosion and sediment control practices be used to protect
surface water quality because of the high potential for sediment loss directly to surface waters.
Sediment and erosion control practices can be borrowed from other applications, such as urban
development and construction activities.
Two broad performance goals constitute this management measure: minimizing erosion and
maximizing the retention of sediment onsite. These performance goals allow for site-specific
flexibility in specifying practices appropriate for local conditions. Regular inspections of a dam
are valuable opportunities for dam owners to identify erosion problems and implement sediment
controls to protect the integrity of the dam. Since the number of new dam construction projects is
relatively small compared to the number of existing dams, operation and maintenance activities
offer significantly more opportunities to prevent NFS problems associated with erosion and
sediment control.
Dam owners are encouraged to establish a program of regular safety inspection of the dam's
infrastructure and dam maintenance. Safety inspection of a dam is a program of regular visual
inspection using simple equipment and techniques. These inspections are often an economical
means of ensuring the long-term safety and survival of a dam structure. By regularly monitoring
the condition and performance of the dam and its surroundings, adequate warning of potentially
unsafe conditions will enable timely maintenance. Being able to recognize the signs of potential
problems and failure, as well as what to do and whom to contact, is vital. Partial or total failure
of a dam may cause extensive damage to downstream areas, including loss of life, property
damage, and impacts to wetlands, riparian areas, stream channels, and other ecologically
important lands, for which the owner may be held liable. There are also potentially expensive
repair costs and lost income that may result from failures or poorly maintained dam structures.
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Chapter 4: Dams
The primary areas of dam structural failure are:
• Loss of clay soils used in berms and other earthen structures
• Seepage and leakage at the base or along pipes
• Erosion, including wave action, stock damage and spillways
• Cracking and movement of structural components
• Defects in associated structures
• Vegetation, including catchment protection and weed control
Operation and maintenance should be applied to small, as well as large dams. Many owners of
small dams, like those on farm ponds, should regularly inspect their dams for maintenance needs.
Local NRCS staff can provide technical assistance to small dam owners for operation and
maintenance activities.3
Regular operation and maintenance efforts can lead to some dams being in need of repairs and/or
upgrades. Designs for repairs and upgrades can involve replacing reinforced concrete risers and
impact basins, replacing rusted out corrugated metal pipe principal spillways, raising the top of
the dams, widening the auxiliary spillways, and removing sediment from the flood pools.
Examples of project costs for these types of maintenance activities reported in Ohio have ranged
from $175,000 on a small dam to $775,000 on the largest dam (Brate, 2004).
At the state and local levels, this measure can be incorporated into existing erosion and sediment
control (ESC) programs. This measure can also be effectively implemented as part of safety
inspection requirements. Erosion and sediment control is also intended to be part of a
comprehensive land use or watershed management program.
Management Practices for Management Measure 3
The management measure can be implemented by applying one or more management practices
appropriate to the source, location, and climate. The practices described below can be applied
successfully to implement the management measure for erosion and sediment control for
construction of new dams and maintenance of existing dams.
Erosion Control Practices
Successful control of erosion and sedimentation from construction and maintenance activities
can involve a system of management practices that targets each stage of the erosion process. The
most efficient approach involves minimizing the potential sources of sediment from the onset.
This means limiting the extent and duration of land disturbance to the minimum needed, and
protecting surfaces once they are exposed. The second stage of the management practice system
involves controlling the amount of runoff and its ability to carry sediment by diverting incoming
flows and impeding internally generated flows. The third stage involves retaining sediment that
is picked up on the project site through the use of sediment-capturing devices. On most sites
3 Contact your local USDA Service Center (http://offices.sc.egov.usda.gov/locator/app') to access NRCS in your
community.
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Chapter 4: Dams
successful erosion and sedimentation control requires a combination of structural and vegetative
practices. All of these stages are better performed using advanced planning and good scheduling.
The timing of land disturbing activities and installation of erosion control measures must be
coordinated to minimize water quality impacts. For large scale activities, the management
practice system is typically installed in reverse order, starting with sediment capturing devices,
followed by key runoff control measures and runoff conveyances, and then land clearing
activities. Often, construction or maintenance activities that generate significant off-site sediment
have failed to sequence activities in the proper order.
Erosion controls reduce the amount of sediment lost during dam construction and prevent
sediment from entering surface waters. Erosion control is based on (1) minimizing the area and
time of land disturbance and (2) quickly stabilizing disturbed soils to prevent erosion.
The effectiveness of erosion control practices can vary based on land slope, the size of the
disturbed area, rainfall frequency and intensity, wind conditions, soil type, use of heavy
machinery, length of time soils are exposed and unprotected, and other factors. In general, a
system of erosion and sediment control practices can more effectively reduce offsite sediment
transport than a single practice. Numerous nonstructural measures such as protecting natural or
newly planted vegetation, minimizing the disturbance of vegetation on steep slopes and other
highly erodible areas, maximizing the distance eroded material must travel before reaching the
drainage system, and locating roads away from sensitive areas may be used to reduce erosion.
The following practices have proven to be useful in controlling erosion and can be incorporated
into ESC plans and used during dam construction as appropriate. These practices can be used
during and after construction and throughout ongoing maintenance activities.
• Bank shaping and planting
• Branch packing
• Brush layering
• Brush mattressing
• Bulkheads and seawalls
• Check dams
• Coconut fiber roll
• Construct runoff intercepts
• Construction management
• Dormant post plantings
• Erosion and sediment control (ESC) plans
• Erosion control blankets
• Joint planting
• Live crib walls
• Live fascines
• Live staking
• Locate potential land disturbing activities away from critical areas
• Mulching
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Chapter 4: Dams
• Noneroding roadways
• Phase construction
• Preserve onsite vegetation
• Retaining walls
• Revegetate
• Revetment
• Riparian improvements
• Riprap
• Rootwad revetments
• Scheduling projects
• Sediment fences
• Seeding
• Site fingerprinting
• Sodding
• Soil protection
• Surface roughening
• Training—erosion and sediment control
• Tree armoring, fencing, and retaining walls or tree walls
• Tree revetments
• Vegetated buffers
• Vegetated filter strips
• Vegetated gabions
• Vegetated geogrids
• Vegetated reinforced soil slope (VRSS)
• Wildflower cover
• Wind erosions controls
A more detailed discussion of each of the above practices is provided in Chapter 7.
Runoff Control
To prevent the entry of sediment used during construction into surface waters, these
precautionary steps should be followed:
• Identify areas with steep slopes, unstable soils, inadequate vegetation density, insufficient
drainage, or other conditions that give rise to a high erosion potential.
• Identify measures to reduce runoff from such areas if disturbance of these areas cannot be
avoided (Hynson et al., 1985).
Runoff diversions are structures that channel upslope runoff away from erosion source areas,
divert sediment-laden runoff to appropriate traps or stable outlets, or capture runoff before it
leaves the site, diverting it to locations where it can be used or released without erosion or flood
damage. Diversions can be either temporary or permanent in nature.
Runoff control measures, mechanical sediment control measures, grassed filter strips, mulching,
and/or sediment basins could be used to control runoff from the construction site. Scheduling
EPA841-B-07-002 4.7 July 2007
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Chapter 4: Dams
construction during drier seasons, exposing areas for only the time needed for completion of
specific activities, and avoiding stream fording also help to reduce the amount of runoff created
during construction.
The largest surface water pollution problem during construction is suspended sediment resulting
from aggregate processing, excavation, and concrete work. Preventing the entry of these
materials above and/or below a dam is always the preferable alternative because runoff due to
these types of construction activities can add more sediment to a reservoir, harm aquatic life
above and below the dam, or affect habitat in streams below a dam. Filtration and gravitational
settling during detention are the main processes used to remove sediment from construction site
runoff. Methods used to control runoff and associated sedimentation from construction sites
include:
• Check dams
• Constructing runoff intercepts
• Locate potential land disturbing activities away from critical areas
• Preserve onsite vegetation
• Retaining walls
• Sediment basins/rock dams
• Sediment fences
• Sediment traps
• Vegetated buffers
• Vegetated filter strips
A more detailed discussion of each of the above practices is provided in Chapter 7.
Erosion and Sediment Control (ESC) Plans
ESC plans can be used to control erosion and sediment and incorporate such control in planning.
Some states call for specific requirements to be included in state ESC plans. Table 4.2 provides
examples of several state ESC plan requirements. Additional detail about ESC plans, including
general objectives, and management techniques for ensure proper administration of plans, is
available in Chapter 7.
Table 4.2 Examples of Erosion and Sediment Control Plan Requirements for Select States
Location
Delaware
Florida
Georgia
Indiana
Maine
Maryland
Michigan
General Requirements for ESC Plan
ESC plans required for sites over 5,000 ft2. Temporary or permanent stabilization
must occur within 14 days of disturbance.
ESC plans required on all sites that need a runoff management permit.
ESC plan required for all land-disturbing activities.
ESC plan required for sites over 5 acres.
ESC plans required for sites adjacent to a wetland or waterbody. Stabilization must
occur at completion or if no construction activity is to occur for 7 days. If temporary
stabilization is used, permanent stabilization must be implemented within 30 days.
ESC plans required for sites over 5,000 ft2 or 100 yd3.
ESC plans required for sites over 1 acre or within 500 ft of a waterbody. Permanent
stabilization must occur within 15 days of final grading. Temporary stabilization is
required within 30 days if construction ceases.
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Chapter 4: Dams
Location
Minnesota
New Jersey
North Carolina
Ohio
Oklahoma
Pennsylvania
South Carolina
Virginia
Washington
Wisconsin
General Requirements for ESC Plan
ESC plans required for land development over 1 acre.
ESC plans required for sites over 5,000 ft2.
ESC plans required for sites over 1 acre. Controls must retain sediment on-site.
Stabilization must occur within 30 days of completion of any phase of development.
ESC plans required for sites over 5 acres. Permanent stabilization must occur within
7 days of final grading or when there is no construction activity for 45 days.
ESC plans required for sites over 5 acres.
ESC plans required for all sites, but the state reviews only plans for sites over 25
acres. Permanent stabilization must occur as soon as possible after final grading.
Temporary stabilization is required within 70 days if construction ceases for more
than 30 days. Permanent stabilization is required if the site will be inactive for more
than 1 year.
ESC plans required for all sites unless specifically exempted. Perimeter controls must
be installed. Temporary or permanent stabilization is required fortopsoil stockpiles
and all other areas within 7 days of disturbance.
For areas within the jurisdiction of the Chesapeake Bay Preservation Act, no more
land is to be disturbed than necessary for the project. Indigenous vegetation must be
preserved to the greatest extent possible.
ESC provisions are incorporated into the state runoff management plan.
ESC plans required for all sites over 4,000 ft3. Temporary or permanent stabilization
is required within 7 days.
(Adapted from Environmental Law Institute, 1998; USEPA, 1993)
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Chapter 4: Dams
Management Measure 4: Chemical and Pollutant Control at Dams
Management Measure 4-
1) Limit application, generation, an4 migration oftoxic substances.
2) Ensure the proper storage an4 4isposal oftoxic materials.
3) Apply nutrients at rates necessary to establish an4 maintain vegetation without
causing significant nutrient runoff to surface waters.
This management measure is intended to be applied to the construction of new dams, as well as
to construction activities associated with the maintenance of dams. This management measure
addresses fuel and chemical spills associated with dam construction and operation and
maintenance activities, as well as concrete washout and related construction activities. The
purpose of this management measure is to prevent downstream contamination from pollutants
associated with dam construction and maintenance activities.
Although suspended sediment is the major pollutant generated at a construction site, other
pollutants that may be present around dams (especially during construction and operation and
maintenance activities) include:
• Petroleum products—fuels and lubricants, specifically gasoline, diesel oil, kerosene,
lubricating oils, grease, and asphalt
• Pesticides—insecticides, herbicides, fungicides, and rodenticides
• Fertilizers
• Construction chemicals—acids, soil additives, and concrete-curing compounds
• Wastewater—aggregate wash water, herbicide wash water, concrete-curing water,
core-drilling wastewater, or clean-up water from concrete mixers
• Solid wastes—paper, wood, metal, rubber, plastic, and roofing materials
• Garbage
• Sanitary wastes
• Cement
• Lime
This management measure is important because most erosion and sediment control practices are
ineffective at retaining soluble NPS pollutants on a construction site. Many of the NPS
pollutants, other than suspended sediment, generated at a construction site are carried offsite in
solution or attached to clay particles in runoff. Some metals (e.g., manganese, iron, and nickel)
attach to larger sediment particles and usually can be retained onsite. Other metals (e.g., copper,
cobalt, and chromium) attach to fine clay particles and have greater potential to be carried
offsite. Insoluble pollutants (e.g., oils, petrochemicals, and asphalt) form a surface film on runoff
water and can be easily washed away (USEPA, 1973; USEPA, 2002b; USEPA, 2005d).
Factors that influence the pollution potential of construction chemicals include:
EPA841-B-07-002 4-10 July 2007
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Chapter 4: Dams
• The nature of the construction and maintenance activity
• The physical characteristics of the construction site
• The characteristics of the receiving water
Dam construction sites are particularly sensitive areas and have the potential to severely impact
surface waters with runoff containing construction chemical pollutants. Because dams are
located on rivers or streams, pollutants generated at these construction sites have a much shorter
distance to travel before entering surface waters. Therefore, chemicals and other NFS pollutants
generated at a dam construction site should be controlled.
Management Practices for Management Measure 4
The management measure generally will be implemented by applying one or more management
practices appropriate to the source, location, and climate. The practices described below can be
applied successfully to implement the control of chemicals and pollutants at dams. This includes
dam construction as well as routine maintenance. Practices for controlling chemicals and
pollutants include the following:
• Equipment runoff control
• Fuel and maintenance staging areas
• Locate potential land disturbing activities away from critical areas
• Pesticide and fertilizer management
• Pollutant runoff control
• Spill prevention and control program
A more detailed discussion of each of the above practices is provided in Chapter 7.
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Chapter 4: Dams
Management Measure 5: Protection of Surface Water Quality and
Instream and Riparian Habitat
Management Measure 5
Develop an4 implement a program to manage the operation of 4ams that inclines an
assessment of.
1) Surface water quality an4 instream an4 riparian habitat an4 potential for
improvement.
2) Significant nonpoint source pollution problems that result from excessive surface
water with4rawals.
This management measure is intended to be applied to dam operation, maintenance, and removal
activities that result in the loss of desirable surface water quality, and of desirable instream and
riparian habitat.
The purpose of the management measure is to protect the quality of surface waters and aquatic
habitat (including riparian habitat) in the portion of rivers and streams that are impacted by dams.
Operation, maintenance, and dam removal activities can be assessed to determine opportunities
for potential improvements in water quality and aquatic habitat. These activities, as well as
actions within the watershed, that contribute NFS pollutants to an impoundment should be
collectively and periodically evaluated to help identify opportunities for cost-effective change.
The recommended overall programmatic approach is to evaluate a set of practices that can be
applied individually or in combination to protect and improve surface water quality and aquatic
habitat in reservoirs, as well as in areas downstream of dams. Then, a program can be
implemented using the most cost-effective operation, maintenance, and removal activities to
protect and improve surface water quality and aquatic and riparian habitat.
The individual application of any particular technique, such as aeration, change in operational
procedure, restoration of an aquatic or riparian habitat, or implementation of a watershed
protection best management practice (BMP), will, by itself, probably not improve water quality
to an acceptable level within the reservoir impoundment or in tailwaters flowing through
downstream areas. The individual practices discussed in this portion of the guidance may have to
be implemented in some combination in order to improve water quality in the impoundment or in
tailwaters to acceptable levels.
Selection of the management measure for the protection of surface water and instream and
riparian habitat was based on:
• The availability and demonstrated effectiveness of practices to improve water quality in
impoundments and in tailwaters of dams.
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Chapter 4: Dams
• The level of improvement in water quality of impoundments and tailwaters that can be
measured from implementation of engineering practices, operational procedures,
watershed protection approaches, or aquatic or riparian habitat improvements.
Successful implementation of the management measure should generally involve the following
categories of practices undertaken individually or in combination to improve water quality and
aquatic and riparian habitat in reservoir impoundments and in tailwaters:
• Artificial destratification and hypolimnetic aeration of reservoirs with deep withdrawal
points that do not have multilevel outlets to improve dissolved oxygen (DO) levels in the
impoundment and to decrease levels of other types of NFS pollutants, such as
manganese, iron, hydrogen sulfide, methane, ammonia, and phosphorus in reservoir
releases.
• Aeration of reservoir releases, through turbine venting, inj ection of air into turbine
releases, installation of reregulation weirs, use of selective withdrawal structures, or
modification of other turbine start-up or pulsing procedures.
• Providing both minimum flows to enhance the establishment of desirable instream habitat
and scouring flows as necessary to maintain instream habitat.
• Establishing adequate fish passage or alternative spawning ground and instream habitat
for fish species.
• Improving watershed protection by installing and maintaining BMPs in the drainage area
above the dam to remove phosphorus, suspended sediment, and organic matter and
otherwise improve the quality of surface waters flowing into the impoundment.
• Removing dams, which are unsafe, unwanted, or obsolete, after careful consideration of
alternatives.
Since the presence and operation of a dam have the potential to cause impacts, periodic
assessments of reservoir water quality, watershed activities, and operational practices may
provide valuable information for evaluating management strategies. The types and severity of the
impacts can serve as an indicator of the frequency and magnitude of the assessments. There are a
variety of assessment tools that are available to assist decision-makers in the evaluation of
impacts associated with dams. Watershed-related impacts and management activities can be
evaluated with a variety of models. EPA supports several models that may be useful for
watershed assessments, such as BASINS.4
4 More information about EPA-supported watershed assessment tools can be found at
http://www.epa.gov/waterscience/wqm.
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Chapter 4: Dams
Reservoir water quality can also be assessed with various models. Table 8-1 in this document
provides a list of models that may be used to assess reservoir water quality. Also presented in
Table 8-1 are models that could be used to evaluate downstream impacts of dams.5
Management Practices for Management Measure 5
The management measure generally can be implemented by applying one or more management
practices appropriate to the source, location, and climate. Management practices that can be used
to achieve the management measure include practices to improve water quality, restore or
maintain aquatic and riparian habitat, and maintain fish passage, as well as possible removal of
dams. The subsection on dam removal includes planning and evaluation considerations,
descriptions of the removal process, permitting requests, sediment removal techniques,
descriptions of changes associated with dam removal, and a discussion of potential biological
impacts.
Practices for Improving Water Quality
Management practices for improving water quality associated with the operation and
maintenance of dams can be categorized as:
• Watershed Protection Practices—activities to reduce NFS pollution that take place within
the watershed surrounding a dam. Reduced NFS pollutant inputs, such as sediment or
nutrients, can have a significant, positive effect on water quality within a reservoir and
often in reservoir releases, as well.
• Practices for Aeration of Reservoir Water—aeration activities within the reservoir. The
primary goal for aerating a large portion of reservoir water is to increase oxygen levels
throughout the reservoir. Other water quality factors may also improve, including levels
of dissolved metals and nutrients, destratification of the water column, and improved
oxygen levels in releases.
• Practices for Aeration of Reservoir Releases —
a variety of aeration techniques for improving
water quality, specifically dissolved oxygen
levels, are presented.
Improving water quality in impoundments and
tailwaters often requires consideration of the
interaction of several different factors. For example,
achievement of desired DO levels at specific projects
may require evaluation of several different
technologies and management activities. The U.S.
Army Corps of Engineers created a computer-modeling
program, AERATE, that performs calculations to
Management practices to protect
surface water quality and instream and
riparian habitat are discussed in the
following subsections:
• Improving Water Quality
o Watershed Protection
o Aeration of Reservoir Water
o Aeration of Reservoir
Releases
• Improving Aquatic Habitat
• Maintaining Fish Passage
• Dam Removal
5 The USAGE Environmental Laboratory develops and supports several models, such as QUAL2E, Bathtub, and
CE-QUAL-RI that can be found at http://el.erdc.usace.army.mil/products.cfm?Topic=none.
EPA841-B-07-002
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July 2007
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Chapter 4: Dams
evaluate several direct (e.g., active aeration technologies) and indirect (e.g., activities such as
watershed management to reduce nitrogen and phosphorous runoff, which result in improved
DO) reservoir aeration techniques. The program considers the following aeration techniques:
improving water quality in the reservoir, modifying the withdrawal outlet location (and thereby
changing which water is withdrawn and released from the reservoir), treating the release water to
eliminate the poor quality as the flow passes through the outlet structure, and treating the release
water in the tail water area (Wilhelms and Yates, 1995).
Additional information about
watershed protection, specifically
developing and implementing
watershed plans, is available from
EPA's draft Handbook for Developing
Watershed Plans to Restore and
Protect Our Waters. The handbook is
available at http://www.epa.gov/nps.
Watershed Protection Practices
Many NFS pollution problems in reservoirs and dam
tailwaters frequently result from sources in the
contributing watershed (e.g., sediment, nutrients, metals,
and toxics). Management of pollution sources from a
watershed has been found to be a cost-effective solution
for improving reservoir and dam tailwater water quality
(TVA, 1988). Watershed protection practices can be
effective in producing long-term water quality benefits
and lack the high operation and maintenance costs associated with structural controls.
Watershed protection is a technique that provides long-term water quality benefits, and many
states and local communities have adopted this practice. Numerous state and local governments
have already legislated and implemented detailed watershed planning programs that are
consistent with this management measure. For example, Oregon, New Jersey, Delaware, and
Florida have passed legislation that requires county and municipal governments to adopt
comprehensive plans, including requirements to direct future development away from sensitive
areas. Many municipalities and regions have adopted land use and growth controls, including the
towns of Amherst and Norwood and the Cape Cod region of Massachusetts; Narragansett, Rhode
Island; King County, Washington; and many others.
Watershed protection management practices fall under the following four categories:
• Encourage drainage protection—includes descriptions and applications of zoning
techniques that can be used to limit development density or redirect density to less
environmentally sensitive areas.
• Establish and protect stream buffers—describes important steps for protecting or
establishing riparian buffer zones to enhance water quality and pollutant removal.
• Identify and address NFS contributions—involves identifying potential upstream sources
of nonpoint source pollution, as well as providing solutions to minimize those impacts.
• Identify and preserve critical areas—entails identifying properties that if preserved or
enhanced could maintain or improve water quality and reduce the impacts of urban
runoff, as well as, preserving environmentally significant areas (includes land acquisition,
easements, and development restrictions of various types).
Refer to Chapter 7 for additional information about each of the above practices.
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Chapter 4: Dams
Reservoir Aeration Practices
Systems that have been developed and tested for reservoir aeration rely on atmospheric air,
compressed air, or liquid oxygen to increase DO concentrations in reservoir waters. Mixing of
reservoir water to destratify warmer, oxygen rich, epilimnion and cooler, oxygen poor,
hypolimnion waters can be used. However, this practice has not been used at large hydropower
reservoirs because of the associated cost in deep, large volume reservoirs. Refer to Chapter 7 for
additional information about reservoir aeration practices.
Practices to Improve Oxygen Levels in Tailwaters
Aeration of water as it passes through the dam or through the portion of the waterway
immediately downstream from the dam is another approach to improving DO in water releases
from dams. The systems in this category rely on agitation and turbulence to mix the reservoir
releases with atmospheric air. One approach involves the increased use of spillways, which
release surface water to prevent it from overtopping the dam. An alternative approach is to install
barriers called weirs in the downstream areas. Weirs are designed to allow water to overtop
them, which can increase DO through surface agitation and increased surface area contact. Some
of these downstream systems create supersaturation of dissolved gases and may require
additional modifications to prevent supersaturation, which may be harmful to aquatic organisms.
The quality of reservoir releases can be improved through adjustments in the operational
procedures at dams. These include scheduling of releases or of the duration of shutoff periods,
instituting procedures for the maintenance of minimum flows, making seasonal adjustments in
the pool levels or in the timing and variation of the rate of drawdown, selecting the turbine unit
that most increases DO (often increasing the DO levels by 1 mg/L), and operating more units
simultaneously (often increasing DO levels by about 2 mg/L). The magnitude and duration of
reservoir releases also should be evaluated to determine impacts to the salinity regime in coastal
waters, which could be substantially altered from historical patterns.
Two factors should be considered when evaluating the suitability of hydraulic structures such as
spillways and weirs for their application in raising the DO concentration in waterways:
• Most of the measurements of DO increases associated with hydraulic structures have
been collected at low-head facilities. The effectiveness of these devices may be limited as
the level of discharge increases (Wilhelms, 1988).
• The hydraulic functioning of these types of structures should be carefully considered
since undesirable flow conditions may occur in some instances (Wilhelms, 1988).
Practices that improve oxygen levels in tailwaters include:
• Gated conduits
• Labyrinth weirs
• Modifying operational procedures
• Reregulation weirs
• Selective withdrawal
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Chapter 4: Dams
• Spillway modifications
• Turbine operation
• Turbine venting
• Water conveyances
Additional information about each of these practices is available in Chapter 7.
Practices to Restore or Maintain Aquatic and Riparian Habitat
Several options are available for the restoration or maintenance of aquatic and riparian habitat in
the area of a reservoir impoundment or in portions of the waterway downstream from a dam.
One set of practices is designed to augment existing flows that result from normal operation of
the dam. These include operation of the facility to produce flushing flows, minimum flows, or
turbine pulsing. Another approach to producing minimum flows is to install small turbines that
operate continuously. Installation of reregulation weirs in the waterway downstream from the
dam can also achieve minimum flows. Finally, riparian improvements are discussed for their
importance and effectiveness in restoring or maintaining aquatic and riparian habitat in portions
of the waterway affected by the location and operation of a dam.
A 2004 report from the National Academies' National Research Council (NRC, 2004) illustrates
the importance of maintaining instream flows and critical wildlife habitat in streams where dams
are present and notes that areas along Nebraska's Platte River are properly designated as "critical
habitats" for the river's endangered whooping crane and threatened piping plover. A series of
dams and reservoirs have been constructed in the river basin for flood control and to provide
water for farm irrigation, power generation, recreation, and municipal use. The alterations to the
river and surrounding land caused by this extensive water-control system, however, resulted in
habitat changes that were at odds with the protection of the listed species.
Conflicts over the protection of federally listed species and water management in the Platte River
Basin have existed for more than 25 years. In recent years, the Fish and Wildlife Service of the
U.S. Department of the Interior issued a series of biological opinions indicating that new water
depletions would have to be balanced by mitigation measures, and a lawsuit forced the
designation of "critical habitat" for the piping plover. These and other controversies prompted
the Department of the Interior and the Governance Committee of the Platte River Endangered
Species Partnership to request that the National Research Council examine whether the current
designations of "critical habitat" for the whooping crane and piping plover are supported by
existing science. The National Research Council was also asked to assess whether current habitat
conditions are affecting the survival of listed species or limiting their chances of recovery, and to
examine the scientific basis for the department's instream-flow recommendations, habitat-
suitability guidelines, and other decisions. The report concludes that in most instances habitat
conditions are indeed affecting the likelihood of species survival and recovery.
Additional information about the following practices to restore or maintain aquatic and riparian
habitat are available in Chapter 7:
• Constructed spawning beds
• Flow augmentation
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Chapter 4: Dams
• Riparian improvements
• Spillway modifications
Practices to Maintain Fish Passage
Migrating fish populations may be unable to travel up or downstream because of the presence of
a dam or suffer losses when passing through the turbines of hydroelectric dams at facilities that
have not been equipped with special design features to accommodate fish passage. The effect of
dams and hydraulic structures on migrating fish has been studied since the early 1950s in an
effort to develop systems or identify operating conditions that would minimize mortality rates.
Selecting a device or management strategy for optimal fish passage in a stream or river with a
dam requires careful analysis of a variety of factors, such as species, type and operational
strategy of the dam, and the physical characteristics of the river system.
Larimer (2000) reports that devices such as fish ladders and bypass channels can help fish travel
past dams, but may result in increased mortality due to the hardship and stress involved with
passing through these structures. In addition, the fish passage structures have to be placed in a
suitable entrance location, have a flow that is attractive to the species of concern, be continually
maintained, and possess the hydraulic conditions necessary for the target species (Larinier,
2000). With all of these requirements, the success of a fish ladder or similar device is often
uncertain. Passage through the hydraulic turbines of a hydropower dam can cause increased
stress as a result of changes in velocity or pressure and the possibility of electric shocks from the
turbines and can lead to increased mortality (Larinier, 2000).
The safe passage offish either upstream or downstream through a dam requires a balance
between operation of the facility for its intended uses and implementation of practices that will
ensure safe passage offish. The United States Congress' Office of Technology Assessment
(OTA) report on fish passage technologies at hydropower facilities provides an excellent
overview offish passage technologies and discusses some of the economic considerations
associated with the safe passage offish (OTA, 1995).
The U.S. Fish and Wildlife Service and its partners have created a database that makes
information about barriers to fish passage in the United States available to policy makers and the
public. The database, known as the Fish Passage Decision Support System (FPDSS),6 is part of
the U.S. Fish and Wildlife Service's National Fish Passage Program.7
Available fish-protection systems for hydropower facilities fall into one of four categories based
on their mode of action (Stone and Webster, 1986): behavioral barriers, physical barriers,
collection systems, and diversion systems. These are discussed in separate sections below, along
with additional practices that have been successfully used to maintain fish passage: spill and
water budgets, fish ladders, fish lifts, advanced hydroelectric turbines, transference offish runs,
and constructed spawning beds.
6https://ecos.fws.gov/fpdss/index.do
7 http://www.fws.gov/fisheries/fwma/fishpassage
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Chapter 4: Dams
Upstream fish passage systems have been constructed at approximately 10 percent of the FERC
licensed hydropower plants. Upstream fish passage systems such as fish ladders and lifts are
considered adequately developed for anadromous species such as salmon, American shad (Alosa
sapidissima), alewives (Alosapseudoharengus), and blueback herring (Alosa aestivalis). Fish
passage systems for riverine fish have not been specifically designed, although some of these
species will use fish passage systems designed for anadromous species (OTA, 1995).
Practices include:
• Advanced hydroelectric turbines
• Behavioral barriers
• Collection systems
• Fish ladders
• Fish lifts
• Physical barriers
• Spill and water budgets
• Transference offish runs
Additional information about the above practices is available in Chapter 7.
Dam Removal Resource
American Rivers is a nonprofit
organization focusing on the health of U.S.
river systems, fish, and wildlife. American
Rivers' website hosts a variety of
information related to hydromodification,
including past and recent estimates of dam
removals in the United States.
http://www.americanrivers.org
Removal of Dams
The removal of dams has become an accepted
practice for dam owners to deal with unsafe,
unwanted, or obsolete dams. Dam removal may be
necessary as dams deteriorate, sediments
accumulate behind dams in reservoirs, human
needs shift, and economics dictate (NRC, 1992).
Dams serve a variety of important social and
environmental purposes (e.g., water supply, flood
control, power generation, wildlife habitat, and
recreation). As a result, dam removal is often infrequent.
Migratory fish passage throughout United States rivers and streams is obstructed by over 2
million dams and many other barriers such as blocked, collapsed, and perched culverts. The
National Oceanic and Atmospheric Administration (NOAA) is expanding its community-based
approach to restoring fish habitat through the recently developed Open Rivers Initiative (ORI).8
Administered by NOAA Fisheries Service Office of Habitat Conservation, ORI is designed to
help communities correct fish passage problems by focusing financial and technical resources on
the removal of obsolete dams and other blockages. ORI strives to restore vital habitat for
migrating fish like salmon, striped bass, sturgeon, and shad, as well as improve community
safety and stimulate economic revitalization of riverfront communities. Through its more broadly
focused Community-based Restoration Program (CRP), NOAA Fisheries Service has opened
over 700 miles of stream habitat with financial and technical assistance provided to fish passage
http://www.nmfs.noaa.gov/habitat/restoration/ORI
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Chapter 4: Dams
projects. Examples of successfully completed CRP projects that fit the Open Rivers Initiative
model include:
• Culvert removal in the John Smith Creek (Mendocino County, CA)
• Mt. Scott Creek dam removal (Happy Valley, OR)
• Wyomissing Creek dam removal (Reading, PA)
• Town Brook dam removal and fish ladder (Plymouth, MA)
• Sennebec dam removal (Union, ME)
There are many things to consider when removing a dam, one of which is the function(s) of the
dam and the status of that function (active vs. inactive). As discussed above, dams are used for
various purposes, including water supply, hydroelectric power, recreation, and flood control
benefits. When proposals are made to remove a dam with one or more of these active functions,
the way in which these functions and benefits will be replaced or mitigated must be addressed
(FOR, 1999). An example of this process can be seen with the Jackson Street Dam, located on
Bear Creek in Medford, Oregon. The dam diverted water from the creek into the irrigation canals
of Rogue River Valley Irrigation District (RRVID). Since the dam created a partial barrier to
migratory fish, a loss of stream habitat, and an algae-filled impoundment near the city park, a
consensus was reached that removing the dam was the most cost-efficient means of eliminating
the problem. However, since the dam was currently providing irrigation diversion, another cost-
efficient diversion had to be devised for RRVID. The decision was made to replace the old dam
with a less damaging diversion structure. The new structure is approximately one-fourth the
height of the Jackson Street Dam (about 3 feet) and is located 1,200 feet upstream. The new
structure is also removed at the end of the irrigation season, which coincides with the time of the
year when most upstream migration occurs. When the new structure is in place during the
irrigation season, it allows fish to migrate (by well-designed fish ladders and screens), and it was
designed so that little water will back up behind it. It is also equipped with fish screens to keep
fish out of the irrigation canal (FOE et al., 1999).
It is also important to consider the cost of
removing a dam, and who will pay for the
removal. Removal costs can vary from tens
of thousands of dollars to hundreds of
millions of dollars, depending on the size
and location of the dam. Who pays for dam
removal can be a complex issue. Removal
in the past has often been financed by the
dam owner; local, state, and federal
government; and in some cases agreements
where multiple stakeholders cover the costs (American Rivers, n.d.a.). A guide to selected
funding sources (Paying for Dam Removal: A Guide to Selected Funding Sources)9 is available
from American Rivers.
Dam owners are responsible to keep the dam safe.
When a dam begins to fail or breach, a decision
must be made as to whether to keep or repair the
structure. When a dam generates no revenue, the
long-term costs of liability insurance, dam and
impoundment maintenance, and operation weigh
heavily on the side of dam removal. On average,
dam removal costs 3-5 times less than repair.
Source: Delaware Riverkeeper, n.d.
'http://www.americanrivers.org/site/DocServer/pdr-color.pdf?docID=727
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Chapter 4: Dams
In the case of the Jackson Street Dam, the most cost-effective alternative to solving the problems
associated with the dam was to remove it. However, since it was currently functioning, an
alternative means to provide that function was needed. In some instances, it is not more
beneficial to remove the dam if it is functioning. For example, USAGE expressed concern over
the costs of air pollution created by fuel-burning power plants needed to replace the lost power
from dams in the debate over the removal of the Snake River dams (Lee, 1999). There was much
controversy over whether it was more cost-efficient to remove the dams, especially due to the
functions the dams provided. USAGE found that replacing the dams would be costly, both
monetarily and ecologically. The estimated costs to replace the lower Snake hydropower were
between $180 million to $380 million a year for 100 years (Lee, 1999). In addition, the cost of
the resulting increase in pollution due to natural gas or coal replacement plants was very high,
yet an actual amount was not determined.
Evaluations made by the USAGE found that the costs associated with removing the Snake River
dams greatly exceeded the costs of maintaining, improving, and keeping them (Associated Press,
2002). Therefore, the dams along the Snake River remain and have been repaired. USAGE plans
to pursue technical and operational changes at the Snake River dams to improve fish survival, in
addition to barging or trucking juvenile salmon around the dams (Associated Press and the
Herald Staff, 2002).
The entire decision-making process is a delicate balance that involves many stakeholders. One
important step in this process is to decide if the ecological benefits of removing the dam
outweigh the benefits of maintaining the dam.
When deciding whether to remove a dam, interested
parties should collect as much information as
possible about the potential removal project.
American Rivers has published a fact sheet (Data
Collection: Researching Dams and Rivers Prior to
Removal),10 which contains a variety of sources to
help begin researching the particular dam that might
be removed and the river on which it is located
(American Rivers, n.d.b.).
American Rivers and Trout Unlimited have
published a guide to help decide whether to remove a
dam or not, Exploring Dam Removal: A Decision-
Making Guide (American Rivers
and Trout Unlimited, 2002).
11
Repercussions of Unsafe Dams
(American Rivers, 1999)
Unsafe dams may result in:
1. Loss of life from surging flows if a
dam fails
2. Destruction of property
3. Harm to the downstream river
environment (e.g., erosion)
4. Release of toxic sediments (e.g.,
dioxins, PCBs)
5. Risk to users of the river (i.e.,
users may not be able to avoid life
threatening hazards if in close
approximation to a failing dam)
6. Jeopardizing delivery of critical
services to communities (e.g.,
power generation, flood control)
The decision-making process related to dam removal is often complex with inputs from
stakeholders with opposing desired outcomes. Additional resources related to dam removal are
available in the Resources chapter.
10 http://www.americanrivers.org/site/DocServer/Reseaching a_Dam_Data Collection. pdf?docID=981
11 http://www.americanrivers.org/site/DocServer/Exploring Dam_Removal-A Decision-
Making Guide.pdf?docID=3641
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Chapter 5: Streambank and Shoreline Erosion
Chapter 5: Streambank and Shoreline Erosion
Figure 5.1 Shoreline Erosion: Before and After Photos (SEAS, 2007)
Streambanks and shorelines naturally erode. Water flowing along (parallel to) streambanks
dislodges sediment and other materials that constitute the Streambank. Similarly, water flowing
perpendicular to shorelines, due to waves or tides, transports sediment and other materials away
from the shoreline. Anthropogenic influences change the natural erosion processes, often
increasing erosion locally and sedimentation downstream, along adjacent shorelines, or offshore.
Many human activities change the hydraulic characteristics of stream flows or transfer energy to
adjacent shorelines and contribute to increased Streambank and shoreline erosion, for example:
• Urbanization that leads to changes in imperviousness creates changes in the hydraulics of
water during wet weather events. Increased imperviousness can result in flashier runoff
events that are shorter in duration with greater flow rates and more erosive force.
• Agricultural practices, such as drainage ditches, can change the characteristics of
subsurface water flows into receiving streams. These changes result in less subsurface
water storage and often increase stream flows during and after storms.
• Livestock grazing may reduce vegetative cover, which can result in more erosion on
uplands and increased sediment and other pollutant loads in streams. Livestock that are
allowed direct access to streams can significantly increase Streambank erosion and
destroy important riparian habitat.
• Roads built in rural areas, such as forest and recreational roads, alter the natural
landscape and can destroy riparian habitat. If not properly installed and maintained, these
types of roads erode and supply increased sediment and pollutants to adjacent streams.
Additionally, roads may increase imperviousness, which leads to flashier runoff events.
Stream crossings associated with rural roads can block fish passage, trap debris during
storms, and lead to increased Streambank erosion in nearby areas.
• Marinas can alter local wave and tidal flow patterns, resulting in transference of wave
and tidal energy to adjacent shorelines.
• Channelization or channel straightening sometimes results in an increase in the slope of
a channel, which causes an increase in stream flow velocities. Channel modifications to
reduce flood damage, such as levees and floodwalls, often narrow the stream width,
increasing the velocity of the water and thus its erosive potential. In addition, newly
EPA841-B-07-002
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July 2007
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Chapter 5: Streambank and Shoreline Erosion
constructed banks are generally more prone to erosion than "seasoned" banks and are
more likely to require bank stabilization.
• Dams alter the flow of water, sediment, organic matter, and nutrients, resulting in both
direct physical and indirect biological effects. The impact of a dam on a stream corridor
can vary, depending on the purposes of the dam and its size in relation to stream flow.
Varying discharges released from a hydropower dam can be a significant factor
increasing streambank erosion. When dams are a barrier to the flow of sediment and
organic materials, the decreased suspended sediment load in release waters may lead to
scouring of downstream streambeds and streambanks.
In summary, these anthropogenic factors can affect the state of equilibrium in streams or along
shorelines. The typical chain of events that follows the disturbance to a stream corridor or
shoreline can be described as changes in:
• Hydrology
• Stream hydraulics
• Morphology
• Factors such as sediment transport and storage
• Alterations to the biological community
• Impervious cover
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Chapter 5: Streambank and Shoreline Erosion
Management Measure 6: Eroding Streambanks and Shorelines
Management Measure 6
1) Where streambank or shoreline erosion is a nonpoint source CNPS) pollution
problem, streambanks an4 shorelines shou!4 be stabilizect. Vegetative metho4s are
strongly preferre4 unless structural metho4s are more effective, considering the
severity of stream flow 4ischarge, wave an4 win4 erosion, an4 offshore
bathymetry, an4 the potential a4verse impact on other streambanks, shorelines,
an4 offshore areas.
2) Protect streambank an4 shoreline features with the potential to re4uce NPS
pollution.
3) Protect streambanks an4 shorelines from erosion 4ueto uses of either the
shorelan4s or a4jacent surface waters.
Typically, several streambank and shoreline stabilization techniques may be used to effectively
control erosion wherever it is a source of nonpoint pollution. Often a combination of techniques
may be necessary to effectively control conditions that are causing the increased erosion.
Techniques involving marsh creation and vegetative bank stabilization ("soil bioengineering")
will usually be effective at sites with limited exposure to strong currents or wind-generated
waves. In cases with increased erosional forces, an integrated approach that employs the use of
structural systems in combination with soil bioengineering techniques can be utilized. The use of
harder, more structural approaches, including beach nourishment and coastal or riparian
structures, may need to be considered in areas facing severe water velocities or wave energy. In
addition to controlling the sources of sediment contributed to surface waters, which are causing
nonpoint source (NPS) pollution, these techniques can halt the destruction of wetlands and
riparian areas located along the shoreline. Once affected streambanks and shorelines are
protected, they can serve as a filter for surface water runoff from upland areas, or as a temporary
sink for nutrients, contaminants, or sediment already present as NPS pollution in surface waters.
Stabilization practices involving vegetation or engineering structures should be properly
designed and installed. These techniques should be applied only when there will be no adverse
effects to aquatic or riparian habitat, or to the stability of adjacent shorelines. In addition to
activities that are applied directly to an eroding streambank or shoreline, there may be
opportunities to promote institutional measures that establish minimum setback requirements or
a buffer zone to reduce concentrated flows and promote infiltration of surface water runoff in
areas adjacent to the shoreline.
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Chapter 5: Streambank and Shoreline Erosion
Stream-friendly Project Tips
Before Construction
Involve your neighbors to increase project success
Get the necessary permits
Flag and avoid disturbing wetlands
Preserve existing native trees and shrubs
Cut trees and shrubs rather than ripping them out of the ground (many may resprout)
Make a plan to replant disturbed areas and use native plants
Install sediment-control practices (e.g., cofferdams)
During Construction
Stockpile fertile topsoil for later use for plants
Use hand equipment rather than heavy equipment
If using heavy equipment, use wide-tracks or rubberized tires
Work from the streambank, preferably on the higher, non-wetland side
Avoid instream work except as authorized by your local fishery and wildlife authority
Stay 100 feet away from water when refueling or adding oil
Avoid using wood treated with creosote or copper compounds
After Construction
Keep out people and livestock during plant establishment
Check project after high flows
Water plants during droughts
Control grass until trees and shrubs overtop grass, usually two to three years
Source: SWCD. No date. Protecting Streambanks from Erosion: Tips for Small Acreages in Oregon.
Washington County Soil and Water Conservation District and the Small Acreage Steering Committee,
Oregon Association of Conservation Districts, http://www.or.nrcs.usda.gov/news/factsheets/fs4.pdf.
Accessed June 2003.
Initially project planners can consider whether a complete removal or reversal of the causative
effects is possible. For example, when evaluating restoration sites affected by upstream armoring
and urbanization, rather than adding armoring to the downstream site that is eroding, the
planning team may consider whether changes to operations up stream can be made. Next,
activities to improve existing erosion damage may be examined. The alteration of operation
approaches in combination with management and restoration efforts can reduce future impacts.
Similarly, removal of channelization structures may allow for a
greater recovery of the integrity of a stream corridor. If
feasible, the objective of a restoration design should be to
eliminate or moderate disruptive influences to allow for
equilibrium (NRC, 1992). If this is not possible, restoration
may have limited effectiveness in the long term or may require
a closer look at an entire watershed to determine alternate
restoration activities. See Chapter 6 for additional information
on watershed planning and restoration information.
A glossary of stream
restoration terms is available
from U.S. Army Corps of
Engineers' Ecosystem
Management and Restoration
Research Program at
http://el.erdc.usace.army.mil/
elpubs/pdf/sr01.pdf.
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Chapter 5: Streambank and Shoreline Erosion
This management measure was selected for the following reasons:
• Many anthropogenic activities can destabilize streambanks and shorelines, resulting in
erosion that contributes significant amounts of NFS pollution in surface waters.
• The loss of coastal land and streambanks due to shoreline and streambank erosion results
in reduction of riparian areas and wetlands that have NFS pollution abatement potential.
• A variety of activities related to use of shorelands or adjacent surface waters can result in
erosion of land along coastal bays or estuaries and loss of land along rivers and streams.
Preservation and protection of shorelines and streambanks can be accomplished through many
approaches, but preference in this guidance is for vegetative practices, such as soil
bioengineering and marsh creation, where their use is appropriate.
Management Practices for Management Measure 6
The management measure generally will be implemented by applying one or more management
practices appropriate to the source, location, and climate. A variety of vegetative and structural
practices are presented and are examples of activities that can be used as a single practice or in
combination with other practices to achieve the desired project goals. An example of a source of
information is the USAGE publication Stream Management (Fischenich and Allen, 2000), which
provides a good summary of vegetative and structural practices as well as a comprehensive
review of processes related to stream and streambank erosion. The document also presents a
thorough overview of planning activities for approaching streambank erosion issues.
The types of practices that can be used to accomplish the elements of Management Measure 6,
including the following groups of practices:
• Vegetative practices
• Structural practices
• Integrated systems
• Planning and regulatory approaches
Vegetative Practices
Vegetative practices have a long history of use in Europe for streambank and shoreline
protection and for slope stabilization. Prior to the 1980s, they have been practiced in the United
States only to a limited extent, primarily because other engineering options, such as the use of
riprap, have been more commonly accepted practices (Allen and Klimas, 1986). The use of
vegetative streambank and shoreline stabilization practices have become more common in the
United States over the past several decades as their implementation has shown to be physically
and ecologically successful. Economically, less costly alternatives of stabilization, such as
vegetative practices, are being pursued as alternatives to engineering structures for controlling
erosion of streambanks and shorelines.
Vegetative practices, sometimes referred to as soil bioengineering, refer to the installation of
plant materials as a main structural component in controlling problems of land instability where
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Chapter 5: Streambank and Shoreline Erosion
erosion and sedimentation are occurring (USDA-NRCS, 1992). Vegetative practices can be
defined as, "the use of live and dead plant materials, in combination with natural and synthetic
support materials, for slope stabilization, erosion reduction, and vegetative establishment"
(FISRWG, 1998).
Basic principles of soil bioengineering include the following (USDA-NRCS, 1992):
• Fit the soil bioengineering system to the site
o Topography and exposure (e.g., note the degree of slope, presence of moisture)
o Geology and soils (e.g., determine soil depth and type)
o Hydrology (e.g., calculate peak flows in the project area)
• Retain existing vegetation whenever possible
• Limit removal of vegetation
• Stockpile and protect topsoil
• Protect areas exposed during construction
• Divert, drain, or store excess water
Additionally, vegetative approaches have the advantage of providing food, cover, and instream
and riparian habitat for fish and wildlife and result in a more aesthetically appealing environment
than traditional engineering approaches (Allen and Klimas, 1986). Many planners of vegetative
practices try to utilize native plants and materials that can be obtained from local stands of
species. These plants are already well adapted to the climate and soil conditions of the area and
thus have an increased chance of becoming established and surviving. The use of locally
available plants also cuts the costs of a restoration project (Gray and Sotir, 1996). Vegetative
systems that use locally available plants have the added advantage of blending in with natural
vegetation over time.
Additional benefits of using bioengineering methods include (USEPA, 2003c):
• Designed to be low maintenance or maintenance-free in the long run
• Enhance habitat not only by providing food and cover sources, but by serving as a
temperature control for aquatic and terrestrial animals
• If successful, can stabilize slopes effectively in a short period of time (e.g., one growing
season)
• Self-repairing after establishment
• Filter overland runoff, increase infiltration, and attenuate flood peaks
The limitations of vegetative practices include the need for skilled laborers and the difficulty of
locating plant materials, particularly during the dormant season, which is the optimal time for
installation. To properly establish a soil bioengineering planting, orientation, on-site training, and
careful supervision of the labor crews are required. Another limitation, which is avoidable, is that
projects that promote the growth of thick vegetation may increase roughness values or increase
friction and raise floodwater elevations. This should be taken into consideration during the
planning stages of a project and prevented.
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Chapter 5: Streambank and Shoreline Erosion
Additional information about soil bioengineering principles is available from the Engineering
Field Handbook, Chapter 18 (USDA-NRCS, 1992).1 Local agencies, such as the USDA Natural
Resources Conservation Service (NRCS) and the Cooperative Extension Service, can be useful
sources of information on appropriate native plant species to consider in bioengineering projects.
The USDA Forest Service has published A Soil Bioengineering Guide for Streambank and
Lakeshore Stabilization,2 which provides information on how to successfully plan and
implement a soil bioengineering project, including the application of soil bioengineering
techniques. The guide also provides specific tips for using soil bioengineering techniques
successfully.
Specific vegetative practices include (USDA-NRCS, 1992):
• Branch packing
• Brush layering
• Brush mattressing
• Coconut fiber roll
• Dormant post plantings
• Live fascines
• Live staking
• Marsh creation and restoration
• Tree revetments
• Vegetated buffers
Refer to Chapter 7 for additional information about the above practices. The Additional
Resources section provides a number of sources for obtaining information about the
effectiveness, limitations, and cost estimates for these practices.
Structural Approaches
Soil bioengineering alone is not suitable in all instances. When considering an approach to
Streambank or shoreline stabilization, it is important to take several factors into account. For
example, it is inappropriate to stabilize slopes with vegetative systems in areas that would not
support plant growth, such as those areas with soils that are toxic to plants, areas of high water
velocity, or where there is significant wave action (Gray and Sotir, 1996). Shores subject to wave
erosion will usually require structures or beach nourishment to dampen wave or stream flow
energy.
Properly designed and constructed shoreline and Streambank erosion control structures are used
in areas where higher water velocity or wave energy make vegetative stabilization and marsh
creation ineffective. In addition to careful consideration of the engineering design, the proper
planning for a shoreline or Streambank protection project will include a thorough evaluation of
1 The soil bioengineering chapter of the handbook is available at http://www.info.usda.gov/CED/ftp/CED/EFH-
Chl8.pdf.
2 Available at http://www.fs.fed.us/publications/soil-bio-guide.
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Chapter 5: Streambank and Shoreline Erosion
the physical processes causing the erosion. To complete the analysis of physical factors, the
following steps are suggested (Hobbs et al., 1981):
• Determine the limits of the shoreline reach
• Determine the rates and patterns of erosion and accretion and the active processes of
erosion within the reach
• Determine, within the reach of the sites of erosion-induced sediment supply, the volumes
of that sediment supply available for redistribution within the reach, as well as the
volumes of that sediment supply lost from the reach
• Determine the direction of sediment transport and, if possible, estimation of the
magnitude of the gross and net sediment transport rates
• Estimate factors such as ground-water seepage or surface water runoff that contribute to
erosion
Some of the most widely accepted alternative engineering practices for streambank or shoreline
erosion control are described below. These practices will have varying levels of effectiveness
depending on the strength of waves, tides, streamflow, or currents at the project site. They will
also have varying degrees of suitability at different sites and may have varying types of
secondary impacts. One important impact that must always be considered is secondary effects,
such as the transfer of wave or streamflow energy, which can cause erosion elsewhere, either
offshore or alongshore. Finding a satisfactory balance between these three factors (effectiveness,
suitability, and secondary impacts) is often the key to a successful streambank or shoreline
erosion control project.
Examples of structural approaches include:
• Beach nourishment
• Breakwaters
• Bulkheads and seawalls
• Check dams
• Groins
• Levees, setback levees, and floodwalls
• Return walls
• Revetment
• Riprap
• Toe protection
• Wing deflectors
Refer to Chapter 7 for additional information about the above practices. The Additional
Resources section provides a number of sources for obtaining information about the
effectiveness, limitations, and cost estimates for these practices.
Integrated Systems
The use of structural systems alone may raise concern because these systems lack vegetation,
which can be effective at stabilizing soils in most conditions. Additionally, vegetated systems
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Chapter 5: Streambank and Shoreline Erosion
can help to restore damaged habitat along shorelines and streambanks. Integrated systems, which
combine structural systems and vegetation, can be very effective in many settings where
vegetation adds support and habitat to structural systems. An example of an integrated system is
the use of stones for toe protection (structural) and soil bioengineering techniques (vegetative)
for the upper banks of a waterway. Integrated slope protection designs that employ the traditional
structural methods and the soil bioengineering techniques have proven to be more cost effective
than either method independently. Where construction methods are labor-intensive and labor
costs are reasonable, the combination of methods may be especially cost effective (Gray and
Sotir, 1996).
Integrated systems include:
• Bank shaping and planting
• Joint planting
• Live crib walls
• Riparian improvements
• Root wad revetments
• Vegetated gabions
• Vegetated geogrids
• Vegetated reinforced soil slope (VRSS)
Refer to Chapter 7 for additional information regarding the above practices. The Additional
Resources section provides a number of sources for obtaining information about the
effectiveness, limitations, and cost estimates for these practices.
Planning and Regulatory Approaches
In addition to the vegetative, structural, and integrated practices discussed above, another group
of practices that can be used to protect streambanks and shorelines includes planning and
regulatory approaches. The variety of planning activities include practices in waters adjacent to
eroding streambanks and shorelines (e.g., evaluating the erosion potential) and on land areas
adjacent to eroding streambanks and shorelines (e.g., watershed planning processes). There are
also a variety of local policy and regulatory activities that can be used to protect sensitive or
eroding streambanks and shorelines ranging from setback requirements and vegetated buffer
minimum widths to requirements for erosion and sediment control plans for various types of
construction activities. The following are examples (with complete descriptions located in
Chapter 7) of planning and regulatory protection activities that could be used to protect
vulnerable streambanks or shorelines:
• Erosion and sediment control plans
• Establishment and protection of stream buffers
• Rosgen's stream classification method
• Setbacks
• Shoreline sensitivity assessment
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Chapter 6: Guiding Principles
Chapter 6: Guiding Principles
Many of the management measures and practices recommended by EPA to reduce the nonpoint
source (NFS) pollutant impacts associated with hydromodification activities stress the need to
incorporate planning as a tool. States, local governments, or community groups should begin the
planning process early when trying to determine how to address a particular NFS issue
associated with a new or existing hydromodification project. The planning process should bring
key stakeholders together so that a variety of options can be explored to adequately define the
problem and potential solutions. Once the issues are identified according to the various
perspectives, project goals can be established to solve one or more environmental problems.
One important part of the planning process is the identification of the goals of the different
stakeholders. Once these goals, which are sometimes different for the different groups of
stakeholders, are identified and defined, the planning team can strive to achieve a balance among
the needs of the various stakeholders. Often restoration compromises can be made to meet
differing goals of the stakeholders to achieve a balance of the needs of the different groups. For
example, changes in hydroelectric dam operation may be possible to produce minimum base
flows downstream from the dam to support a variety of aquatic habitats, while still providing
energy in a profitable manner. In addition, solutions that only allow for complete removal of the
dam and restoration to preexisting stream conditions may not be possible because of other
changes in the watershed (e.g., urbanization, other hydromodification projects, or the need for
affordable and environmentally friendly electricity). A compromise solution that enables the dam
to continue to operate while minimizing environmental impacts and to enhance critical
downstream habitats that support a desirable fish population may be the best solution.
Part of the planning process and achievement of balance when evaluating techniques for
restoring areas impacted by NFS pollution associated with hydromodification activities can be
termed "creating opportunities." For example, an opportunity may be found by working with
stakeholders such as local homeowners who are concerned about the unsightly algae present in a
community reservoir. Reducing runoff containing an abundant supply of nitrogen and
phosphorous pollutants from lawns surrounding the reservoir may lead to reductions in the algal
bloom. Changes in land use that result in increasing the permeability of land adjacent to a
channelized stream can reduce the overall volume and velocity of water in the stream. As
flooding conditions are reduced, "hard" structures like bulkheads can be replaced with softer,
vegetative solutions along the stream channel. The combination of reduced scouring flows
associated with the greater stream velocities and vegetated channel banks can lead to improved
instream ecological conditions. There are many other possible opportunities waiting to be found
and implemented when projects are evaluated at the watershed level.
Project planning and analysis are essential parts of success when trying to reduce the impact of
NPS pollution from new or existing hydromodification activities. One example of a planning
process is explained in the EPA document Ecological Restoration: A Tool to Manage Stream
Quality (USEPA, 1995a). This document outlines the key steps in the ecological restoration
decision framework as:
• Identification of impaired or threatened watersheds
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Chapter 6: Guiding Principles
• Inventory of the watershed
• Identification of the restoration goals
• Selection of candidate restoration techniques
• Implementation of selected restoration techniques
• Monitoring
Other EPA guidance documents offer similar approaches to the restoration planning process,
including Community-Based Environmental Protection: A Resource Book for Protecting
Ecosystems and Communities (USEPA, 1997a). Both guidance documents offer a variety of case
studies to provide readers with examples of the frameworks as they are applied to real-world
situations. EPA's Draft Handbook for Developing Watershed Plans to Restore and Protect Our
Waters (USEPA, 2005c) also provides useful planning information related to watershed plans.
The Natural Resources Conservation Service (NRCS) is also a source of information for
planning. NRCS provides assistance through their Watershed Protection and Flood Prevention
Program, whose purpose is to assist federal, state, local agencies, local government sponsors,
tribal governments, and program participants to protect and restore watersheds from damage
caused by erosion, floodwater, and sediment; to conserve and develop water and land resources;
and to solve natural resource and related economic problems on a watershed basis. The program
provides technical and financial assistance to local people or project sponsors, builds
partnerships, and requires local and state funding contribution. *
NRCS uses locally-led conservation programs, which are an extension of the agency's traditional
assistance to individual farmers and ranchers, for planning and installing conservation practices
for soil erosion control, water management, and other purposes. Through this effort, local people,
generally with the leadership of conservation districts along with NRCS technical assistance, will
assess their natural resource conditions and needs, set goals, identify ways to solve resource
problems, utilize a broad array of programs to implement solutions, and measure their success.
When planning any new development activities or restoration of already developed or impacted
activities, it is important to account for the guiding principles:
• Using a watershed approach
• Smart growth principles
• Project design principles
• Monitoring and maintenance of structures
Each of these principles is discussed in more detail below.
1 Additional information about this program, as well as contact information is available at
http://www.nrcs.usda.gov/programs/watershed.
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Chapter 6: Guiding Principles
Using a Watershed Approach
EPA recommends the use of a watershed approach as the key framework for dealing with
problems caused by runoff and other sources that impair surface waters (USEPA, 1998). The
watershed protection approach is a comprehensive planning process that considers all natural
resources in the watershed, as well as social, cultural, and economic factors. Using a watershed
approach, multiple stakeholders integrate regional and locally-led activities with local, state,
tribal, and federal environmental management programs. EPA works with federal agencies,
states, tribes, local communities, and non-governmental sectors to make a watershed approach
the key coordinating framework of planning, restoration, and protection efforts to achieve "clean
and safe" water and healthy aquatic habitat.
The watershed approach framework can be applied to address impacts caused by
hydromodification activities throughout a watershed. Additionally, the watershed approach can
help to identify and address problems within a watershed that increase NPS pollution associated
with hydromodification activities.
Major elements of successful watershed approaches include:
• Focusing on hydrologically-defined areas—watersheds and aquifers have hydrologic
features that converge to a common point of flow; watersheds range in size from very
large (e.g., the Mississippi River Basin) to a drainage basin for a small creek.
• Using an integrated set of tools and programs (regulatory and voluntary,
federal/state/tribal/local and non-governmental sectors) to address the myriad problems
facing the Nation's water resources, including NPS and point source pollution, habitat
degradation, invasive species, and air deposition of pollutants (e.g., mercury and
nutrients).
• Involving all parties that have a stake or interest in developing collaborative solutions to a
watershed's water resource problems.
• Using an iterative planning or adaptive management process of assessment and setting
environmental, water quality, and habitat goals (e.g., water quality standards).
• Planning, implementation, and monitoring to ensure that plans and implementation
actions are revised to reflect new data.
• Breaking down barriers between plan development and implementation to enhance
prospects for success.
A key attribute of the watershed approach is that it can be applied with equal success to large-
and small-scale watersheds. Federal agencies, states, interstate commissions, and tribes usually
apply the approach on larger scales, such as in watersheds greater than 100 square miles in size.
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Chapter 6: Guiding Principles
However, local agencies and urban communities can apply the approach to watersheds as small
as several acres in size.
Although specifics may vary from large scale to small scale, the basic goals of the watershed
approach remain the same—protecting, maintaining, and restoring water resources, based on the
geomorphology, ecology, and other natural characteristics of the waterbody. Local runoff
management program officials must be especially conscious of watershed scale when planning
and implementing specific management practices. For example, programmatic practices, such as
stream protection ordinances and public education campaigns, are usually applied community
wide. Consequently, the results benefit many small watersheds. In contrast, structural practices,
such as vegetative approaches, usually provide direct benefits to a single stream. Regional
structural management practices such as headland breakwater systems for larger watersheds can
be used, but they do not protect smaller contributing streams. Given limited resources, program
officials must often analyze cost and benefits and choose between large- and small-scale
practices. Often, a combination of nonstructural and structural practices implemented across the
watershed and at regional and local levels is the most cost effective approach.
An example of the watershed approach being used for hydromodification activities is the South
Myrtle Creek Ditch Project. South Myrtle Creek, which flows into the South Umpqua River in
Oregon, was historically populated with cutthroat trout (Oncorhynchus clarki) and coho salmon
(Oncorhynchus kisutch). However, since the early 20th century, diversion structures, used
primarily to provide water for irrigating agricultural crops, have blocked the passage offish
through creek waters (USEPA, 2002c). One example of the diversion structures was a diversion
dam with a concrete apron, which was installed in a portion of South Myrtle Creek to raise the
water level in an impoundment to provide irrigation water for adjacent and downstream
landowners. During the summer, water levels in the creek would elevate 14 feet above natural
levels and were diverted into a 2.5 mile irrigation ditch. Ultimately, hydromodification of this
stream caused flow modifications and high stream temperatures, which degraded water quality
for the native trout and salmon populations.
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Chapter 6: Guiding Principles
9 Elements of Watershed Planning
EPA has identified a minimum of nine elements that are critical for achieving improvements in water
quality. EPA requires that these nine elements be addressed for section 319-funded watershed plans
and strongly recommends that they be included in all other watershed plans that are intended to
remediate water quality impairments. Additional information is available from FY 2004 Guidelines for
the Award of Section 319 Nonpoint Source Grants to States and Territories at
http://www.epa.ciov/owow/nps/cwact.html. The nine elements are listed below:
a. Identification of causes of impairment and pollutant sources or groups of similar sources that need
to be controlled to achieve needed load reductions, and any other goals identified in the watershed
plan. Sources that need to be controlled should be identified at the significant subcategory level along
with estimates of the extent to which they are present in the watershed (e.g., X linear miles of eroded
streambank needing remediation).
b. An estimate of the load reductions expected from management measures.
c. A description of the nonpoint source management measures that will need to be implemented to
achieve load reductions and a description of the critical areas in which those measures will be needed
to implement this plan.
d. Estimate of the amounts of technical and financial assistance needed, associated costs, and/or the
sources and authorities that will be relied upon to implement this plan.
e. An information and education component used to enhance public understanding of the project and
encourage their early and continued participation in selecting, designing, and implementing the
nonpoint source management measures that will be implemented.
f. Schedule for implementing the nonpoint source management measures identified in this plan that is
reasonably expeditious.
g. A description of interim measurable milestones for determining whether nonpoint source
management measures or other control actions are being implemented.
h. A set of criteria that can be used to determine whether loading reductions are being achieved over
time and substantial progress is being made toward attaining water quality standards.
i. A monitoring component to evaluate the effectiveness of the implementation efforts overtime,
measured against the criteria established under item h immediately above.
In 1998 one of the landowners initiated a project to restore flow and improve water quality in
South Myrtle Creek. The project used the guiding principles of the watershed approach to restore
the health of the creek.
• Partnership. The project was a collaborative effort of landowners, who donated services
and supplies. The project received funding and support from government agencies, such
as the U.S. Fish and Wildlife Service, the Oregon Water Resources Department, the
Oregon Watershed Enhancement Board, the Bureau of Land Management, the Natural
Resources Conservation Service, and the Douglas County Watermaster.
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Chapter 6: Guiding Principles
• Geographic focus. Resource management activities were directed specifically to the
creek and the drainage ditch, where flow restoration and improved water quality were
desired.
• Sound management techniques based on strong science and data. An assessment of
South Myrtle Creek identified water quality problems from flow modification and high
stream temperatures as the priority problems in the creek. The diversion dam and
concrete apron were found to be causing the problems. Landowners, the Water Resources
Department, and the Watershed Enhancement Board developed a plan, the goal of which
was to restore flow and improve water quality in the creek. The plan was implemented by
removing the diversion dam and concrete apron. The irrigation system was switched to a
sprinkler type system, which is more efficient than the original ditch irrigation. In
addition, the denuded riparian area was revegetated to help lower stream temperatures
and new seedlings were protected with fencing to keep away livestock.
With the cooperation of the landowners, the county and state governments, and other interested
parties, the South Myrtle Creek Ditch Project was a success. Water temperatures have improved
and flows have increased by 2.5 cubic feet per second during the summer. Restoration of the
streambed to its historical level has allowed passage of salmon and trout to the 10 miles of
stream above the dam (USEPA, 2002c).2
Smart Growth
Smart growth practices cover a range of development and conservation strategies that are
environmentally sensitive, economically viable, community-oriented, and sustainable.
Environmental impacts of development can be reduced with techniques that include compact
development, reduced impervious surfaces and improved water detention, safeguarding of
environmentally sensitive areas, mixing of land uses (e.g., homes, offices, and shops), transit
accessibility, and better pedestrian and bicycle amenities.
Through smart growth approaches that enhance neighborhoods and involve local residents in
development decisions, these communities are creating vibrant places to live, work, and play.
The high quality of life in these communities makes them economically competitive, creates
business opportunities, and improves the local tax base. Smart growth practices have also been
shown to help protect water quality by reducing the amount of paved surfaces and allowing
natural lands to filter rainwater and runoff before it reaches downstream areas.
Based on the experience of communities around the nation that have used smart growth
approaches to create and maintain great neighborhoods, the Smart Growth Network3 developed a
set often basic principles:
2 Additional information about the project is available at http://www.epa.gov/owow/nps/Section319III/OR.htm.
3 Smart Growth Network (SON) is a partnership of government, business, and civic organizations that support smart
growth. The SON Web site, Smart Growth Online (http://www.smartgrowth.org/Default.asp?res=1024X features an
extensive array of smart growth-related news, events, information, research, presentations, and publications.
EPA841-B-07-002 6-6 July 2007
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Chapter 6: Guiding Principles
1. Mix land uses
2. Take advantage of compact building design
3. Create a range of housing opportunities and choices
4. Create walkable neighborhoods
5. Foster distinctive, attractive communities with a strong sense of place
6. Preserve open space, farmland, natural beauty, and critical environmental areas
7. Strengthen and direct development towards existing communities
8. Provide a variety of transportation choices
9. Make development decisions predictable, fair, and cost effective
10. Encourage community and stakeholder collaboration in development decisions
EPA offers help to communities through the EPA smart growth program to improve
development practices and get the type of development they want. They work with local, state,
and national experts to discover and encourage successful, environmentally sensitive
development strategies. EPA is engaged in conducting research, publishing reports and other
publications,4 showcasing outstanding communities, working with communities through grants5
and technical assistance (Smart Growth Implementation Assistance Program),6 and bringing
together diverse interests to encourage better growth and development.7
Low Impact Development
Low Impact Development (LID) is an innovative stormwater management approach. The goal of
LID is to mimic a site's predevelopment hydrology by using design techniques that infiltrate,
filter, store, evaporate, and detain runoff close to its source (Low Impact Development Center,
Inc., n.d.).
LID is based on the paradigm that stormwater management should not be viewed as stormwater
disposal and that numerous opportunities exist within the developed landscape to control
stormwater runoff close to the source. These principles include (NRDC, n.d.):
• Integrate stormwater management early in site planning activities
• Use natural hydrologic functions as the integrating framework
• Focus on prevention rather than mitigation
• Emphasize simple, low-tech, and low cost methods
• Manage as close to the source as possible
• Distribute small-scale practices throughout the landscape
• Rely on natural features and processes
• Create a multifunctional landscape
4 http://www.epa.gov/piedpage/publications.htm
5 http://www.epa.gov/piedpage/grants/index.htm
6 http://www.epa.gov/piedpage/sgia.htm
7
Links to technical assistance, tools, partnerships and grants and other funding are at "Making Smart Growth
Happen" at http://www.epa.gov/piedpage/sg implementation.htm.
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Chapter 6: Guiding Principles
The use of LID practices offers both economic and environmental benefits. LID measures result
in less disturbance of the development area and conservation of natural features, and they can be
less cost intensive than traditional stormwater control mechanisms. Cost savings for control
mechanisms are not only for construction, but also for long-term maintenance and life cycle cost
considerations (USEPA, 2000).
Ten common LID practices are the following (NRDC, n.d.):
• Impervious surface reduction and disconnection
• Permeable pavers
• Pollution prevention and good housekeeping
• Rain barrels and cisterns
• Rain gardens and bioretention
• Roof leader disconnection
• Rooftop gardens
• Sidewalk storage
• Soil amendments
• Tree preservation
• Vegetated swales, buffers, and strips
Project Design Considerations
General Design Factors
When designing any type of restoration project, it is important to consider the watershed as a
whole as well as the specific site where restoration will occur. A watershed survey, or visual
assessment, evaluates an entire watershed and can be used to help identify and verify pollutants,
sources, and causes of impairments that lead to changes in streambank erosion. Additional
monitoring of chemical, physical, and biological conditions may be necessary to determine if
water quality is actually being affected by observed pollutants and sources. Watershed surveys
can provide an accurate picture of what is occurring in the watershed. EPA's Volunteer Stream
Monitoring: A Methods Manuaf provides a watershed survey visual assessment form that may
be used. In addition to EPA's method, a variety of visual assessment protocols have been
developed by states and agencies. Designers of watershed restoration plans should look for
assessment protocols that are already being used in their state or local area (USEPA, 2005c).
Another general resource for planning and implementing restoration projects associated with
hydromodification activities is EPA's National Management Measures to Protect and Restore
Wetlands (USEPA, 2005b).
Photographs may also be a powerful tool that can be incorporated into watershed surveys. Photos
serve as a visual reference for the site and provide before and after pictures that may be used to
analyze restoration or remediation activities. In addition to taking individual photographs, aerial
photographs may also provide important before and after information and can be obtained from
1 http://www.epa.gov/owow/monitoring/volunteer/stream/vms32.html
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Chapter 6: Guiding Principles
USGS (Earth Science Information Center), USDA (Consolidated Farm Service Agencies, Aerial
Photography Field Office), and other agencies (USEPA, 2005c). Refer to EPA's draft Handbook
for Developing Watershed Plans to Restore and Protect Our Waters (USEPA, 2005c) for more
information about watershed assessments.
Assessment
Tools to analyze channels on a site-by-site basis may include geomorphic assessments such as
the methodology developed by Rosgen. Geomorphic assessments help to determine river and
stream characteristics such as channel dimensions, reach slope, and channel enlargement and
stability. This information about stream physical characteristics might help the restoration team
to understand current stream conditions and may be evaluated over time to describe degradation
or improvements in the stream. Geomorphic assessment may also be useful for predicting future
stream conditions, which can help in selecting suitable restoration or protection approaches
(USEPA, 2005c).
The Rosgen geomorphic assessment approach groups streams into different geomorphic classes,
based on a set of criteria that include entrenchment ratio, width/depth ratio, sinuosity, channel
slope, and channel materials. Assessment methodologies, such as Rosgen's Stream Classification
System, can help identify streams at different levels of impairment, determine the types of
hydrologic and physical factors affecting stream morphologic conditions, and choose appropriate
management measures to implement if needed.9 Another common geomorphic assessment
method is the Modified Wolman Pebble Count (Harrelson et al., 1994), which characterizes the
texture (particle size) in the stream or riverbeds of flowing surface waters. It can be used alone or
with Rosgen-type assessments. The composition of the streambed can provide information about
the characteristics of the stream, including effects of flooding, sedimentation, and other physical
impacts on a stream (USEPA, 2005c). Other assessment methods may be available from state
agencies or environmental organizations.
The physical conditions of a site can provide important information about factors affecting
overall stream integrity, such as agricultural activities and urban development. Runoff from
cropland and feedlots can carry sediment into streams, clog existing habitat, and change
geomorphological characteristics. An understanding of stream physical conditions can facilitate
identification of sources and pollutants and allow for designing and implementing more effective
restoration and protection strategies. Physical characterization should also extend beyond the
streambanks or shore and include a look at conditions in riparian areas (USEPA, 2005c).
Before choosing a practice to restore an area impacted by hydromodification activities, it is also
important to determine what biological endpoints are desired and to consider other
environmental or water quality goals. Biological endpoints may include metrics such as the
number offish surviving, number of offspring produced, impairment of reproductive capability,
or morbidity. Biological endpoints can be used to evaluate the effectiveness of treatment
schemes and can serve as a design parameter during restoration planning. Water quality goals,
such as increasing low dissolved oxygen levels, reducing nitrogen or phosphorous pollutant
9 More information about the Rosgen Stream Classification System is available at
http://www.epa.gov/watertrain/streamclass/index, htm.
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Chapter 6: Guiding Principles
levels, or decreasing turbidity, are also important to consider when planning restoration. For
example, if turbidity is a major problem in the waterbody, planners will want to choose a method
of restoration that prevents erosion, is efficient at trapping sediment before it enters the
waterbody, or one that will help sediment to settle in desired locations of the stream or river.
Looking at endpoints and goals before designing the method of restoration can help planners and
stakeholders achieve the desired results.
Engineering Considerations
When choosing from the various alternatives of engineering practices for addressing impacts
associated with hydromodification, such as protecting and restoring eroding streambanks and
shorelines, the following factors should be taken into consideration:
• Foundation conditions
• Level of exposure to erosive forces
• Availability of materials
• Initial and annual costs
• Past performance
Foundation conditions may have a significant influence on the selection of the specific practice
or combination of practices to be used for restoring areas impacted by hydromodification,
including shoreline or streambank stabilization. Foundation characteristics at the site must be
compatible with the structure that is to be installed for erosion control. A structure such as a
bulkhead, which must penetrate through the existing substrate for stability, will generally not be
suitable for shorelines with a rocky bottom. Where foundation conditions are poor or where little
penetration is possible, a gravity-type structure such as a stone revetment may be preferable.
However, all vertical protective structures (revetments, seawalls, and bulkheads) built on sites
with soft or unconsolidated bottom materials can experience scouring as incoming waves are
reflected off the structures. In the absence of additional toe protection in these circumstances, the
level of scouring and erosion of bottom sediments at the base of the structure may be severe
enough to contribute to structural failure at some point in the lifetime of the installation.
Along streambanks, the erosive force of the current during periods of high streamflow will
influence the selection of bank stabilization techniques and details of the design. For shorelines,
the levels of wave exposure at the site will also generally influence the selection of shoreline
stabilization techniques and details of the design. In areas of severe levels of exposure to erosive
forces, such as strong wave action or currents, light structures such as vegetative techniques,
timber cribbing, or light riprap revetment may not provide adequate protection. The effects of
winter ice along the shoreline or streambank may also need to be considered in the selection and
design of erosion control projects.
The availability of materials is another key factor influencing the selection of suitable techniques
for protecting and restoring areas affected by hydromodification activities. For a vegetative
approach, availability of plant materials of sufficient quantity and quality is an important design
consideration. A particular type of bulkhead, seawall, or revetment may not be economically
feasible if materials are not readily available near the construction site. Installation methods may
also preclude the use of specific structures in certain situations. For instance, the installation of
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Chapter 6: Guiding Principles
bulkhead pilings in coastal areas near wetlands may not always be permissible due to disruptive
impacts in locating pile-driving equipment at the project site.
Costs should also be included in the decision making process for implementing
hydromodification practices. The total cost of a project should be viewed as including both the
initial costs (materials, labor, and planning) and the annual costs of operation and maintenance.
To the extent possible, practices should be compared by their total costs. Although a particular
practice may be cheaper initially, it could have operation and maintenance costs that make it
more expensive in the long run. For example, in some parts of the country, the initial costs of
timber bulkheads may be less than the cost of stone revetments. However, stone structures
typically require less maintenance and have a longer life than timber structures. Other types of
structures whose installation costs are similar may actually have a wide difference in overall cost
when annual maintenance and the anticipated lifetime of the structure are considered (USAGE,
1984). Environmental benefits, such as creation of habitat, should also be factored into cost
evaluations.
An example of a valuable resource that provides specific cost information for practices to protect
or reduce streambank and shoreline erosion is your local USDA Service Center, which makes
available services provided by the NRCS.10
The engineering designers should also evaluate similar existing projects and practice designs to
determine how well they performed compared to design specifications. An important
consideration for determining past performance is to compare the physical, water quality, and
biological endpoints specified in the design with the corresponding endpoints that were observed
in the monitoring results. For example, if an operation and maintenance program for an urban
channelization project incorporates establishment of vegetative cover along many of the low
energy areas of an urban stream, the long-term performance of the vegetative cover can be
evaluated with metrics such as:
• Percent of riparian area with erosion problems
• Number of recreationally important fish species present
• Annual operation and maintenance costs
• Changes in important water quality parameter values (e.g., dissolved oxygen, turbidity)
Incorporating Monitoring and Maintenance of Structures
Generally, the monitoring program will help to determine how well the project is performing
with respect to the design goals and the extent of any maintenance activities needed (NRC,
1992). The project monitoring plan should be an integral part of the overall design and will be an
important consideration for developing long-term project costs and resource needs. Once the
project's goals are established, performance indicators are then matched to the goals to create the
10 A list of USDA Service Centers is available at http://offices.sc.egov.usda.gov/locator/app. A list of regional and
state NRCS offices is available at http://www.nrcs.usda.gov/about/orgardzation/regions.htmrffstate.
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Chapter 6: Guiding Principles
monitoring program (NRC, 1992). The monitoring program should also be appropriate to the
scope of the project (NRC, 1992) by including considerations such as:
• The area covered by the monitoring compared to the area of the overall project—both
should be similar.
• The frequency and intensity of sampling to provide reliable assessments of the
performance indicators.
• The cost and resources required for monitoring should reflect the overall cost and
resources of the project.
• The performance indicators provide information to enable effective assessments of the
project goals and decision-making for project maintenance activities.
Each project will have unique goals and corresponding monitoring needs. Chapter 3 of The
National Research Council's document Restoration of Aquatic Ecosystems (NRC, 1992)
provides detailed advice on considerations for planning a monitoring program for restoration
activities such as those associated with hydromodification activities. Some additional monitoring
considerations can be found in the USD A Forest Service document^ Soil Bioengineering Guide
for Streambank andLakeshore Stabilization (USDA-FS, 2002):
• Keeping track of where plants were harvested—is there a correlation between growth rate
of certain cuttings and the "mother" plants?
• Is the installation functioning as designed?
• Which areas are maturing more rapidly than others?
• Are seeds sprouting in the newly formed beds?
• Which plants have invaded the site through natural succession?
• What has sprouted in the second season?
• Which areas are experiencing difficulty and why?
• Is the bank stabilizing or washing away and why?
• Is something occurring that is unexpected?
• Which techniques are succeeding?
• Are any of the structures failing?
USDANRCS' The Practical Streambank Bioengineering Guide11 (Bentrup and Hoag, 1998)
provides an example monitoring form. The monitoring sheet is also available in Appendix C of A
Soil Bioengineering Guide for Streambank and Lakeshore Stabilization (USDA-FS, 2002).12
During the first few years after installation, maintenance is necessary until vegetation becomes
established and the bank stabilizes. Structures may shift or you may notice something that was
left undone. Once vegetation is established, projects should become self-sustaining and require
little or no maintenance. Be sure the site is managed to give the treatment every chance to be
effective over a long period of time (USDA-FS, 2002).
11 http://www.engr.colostate.edu/~bbledsoe/CE413/idpmcpustguid.pdf
12 http://www.fs.fed.us/publications/soil-bio-guide/guide/appendices.pdf
EPA841-B-07-002 6-12 July 2007
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Chapter 6: Guiding Principles
Common maintenance tasks include (USDA-FS, 2002; Bentrup and Hoag, 1998):
• Remove debris and weeds that may shade and compete with cuttings
• Secure stakes, wire, twine, etc.
• Control weeds
• Repair weakened or damaged structures (including
fences)
• Replant and reseed as necessary (it is not uncommon
for a flood to occur days after installation)
It is beneficial to inspect the project every other week for the
first 2 months after installation, once a month for the next 6
months, and then every other month for 2 years, at least. One
should also inspect the project after heavy precipitation,
flooding, snowmelt, drought, or any extraordinary occurrence.
Assess damage from flooding, wildlife, grazing, boat wakes, trampling, drought, and high
precipitation (USDA-FS, 2002). Additional information about monitoring is available from
USDANRCS' The Practical StreambankBioengineering Guide (Bentrup and Hoag, 1998).
Planting success varies from
project to project. Bentrup and
Hoag (1998) provide the
following potential growth
success rates:
Pole Plantings 70-100%
Live Fascines 20-50%
Brush Layering 10-70%
Post Plantings 50-70%
Plan and design all
streambank, shoreline, and
navigation structures so that
they do not transfer erosion
energy or otherwise cause
visible loss of surrounding
streambanks or shorelines.
Maintenance varies with the structural type. For stone
revetments, the replacement of stones that have been
dislodged is necessary; timber bulkheads need to be backfilled
if there has been a loss of upland material, and broken sheet
pile should be replaced as necessary. Gabion baskets should
be inspected for corrosion failure of the wire, usually caused
either by improper handling during construction or by
abrasion from the stones inside the baskets. Baskets should be
replaced as necessary since waves will rapidly empty failed baskets.
Steel, timber, and aluminum bulkheads should be inspected for sheet pile failure due to active
earth pressure or debris impact and for loss of backfill. For all structural types not contiguous to
other structures, lengthening of flanking walls may be necessary every few years. Through
periodic monitoring and required maintenance, a substantially greater percentage of coastal
structures will perform effectively over their design life. Since streambank or shoreline
protection projects can transfer energy from one area to another, which causes increased erosion
in the adjacent area, the possible effects of erosion control measures on adjacent properties
should be routinely monitored.
EPA841-B-07-002
6-13
July 2007
-------
Chapter 7: Practices for Implementing Management Measures
Chapter 7: Practices for Implementing Management Measures
Many of the operation and maintenance solutions presented in Chapter 3 (Channelization and
Channel Modification) are also practices that can be used to stabilize streambanks and shorelines
as presented in Chapter 5 (Streambank and Shoreline Erosion). For example, a stream channel
that has been hardened with vertical concrete walls to prevent local flooding and limit the stream
to its existing channel (to protect property built along the stream channel), may benefit from
operation and maintenance practices that use opportunities to replace the concrete walls with
appropriate vegetative or combined vegetative and non-vegetative structures along the
streambank when possible. These same practices may be applicable to stabilize downstream
streambanks that are eroding and creating a nonpoint source (NFS) pollution problem because of
the upstream development and hardened streambanks.
The following practices apply to one or more management measures. The descriptions and
illustrations presented in this chapter are intended to provide a starting point for stakeholders and
decision-makers for selecting possible practices to address NFS pollution problems associated
with hydromodification activities. Table 7.1 provides a cross-reference of the practices with
possible applications for the various hydromodification management measure components (e.g.,
instream and riparian restoration corresponds to the second component of Management Measures
1 and 2 described in detail in Chapter 3). Users of the information provided in the following table
and descriptions evaluate the attributes of the possible practices with site-specific conditions in
mind.
EPA841-B-07-002 7-1 July 2007
-------
Table 7.1 Practices for Hydromodification Management Measures
Practices
Advanced Hydroelectric
Turbines (7-7)
Bank Shaping and Planting
(7-9)
Beach Nourishment (7-10)
Behavioral Barriers (7-12)
Branch Packing (7-14)
Breakwaters (7-1 5)
Brush Layering (7-17)
Brush Mattressing (7-19)
Bulkheads and Seawalls (7-21)
Check Dams (7-22)
Coconut Fiber Roll (7-23)
Collection Systems (7-25)
Construct Runoff Intercepts
(7-26)
Constructed Spawning Beds
(7-27)
Construction Management
(7-28)
Dormant Post Plantings (7-29)
Channelization
Physical & chemical
MM1
•
•
•
Instream/riparian restoration
MM2
•
•
•
Dams
Erosion control
Runoff control
MM3
•
•
•
•
•
•
•
Chemical/pollutant control
MM4
Watershed protection
Aerate reservoir water
Improve tailwater oxygen
Restore/maintain habitat
Maintain fish passage
MM5
•
•
•
•
Streambanks
Vegetative
Structural
Integrated
Planning & regulatory
Shorelines
Vegetative
Structural
Integrated
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Encourage Drainage Protection
(7-30)
Equipment Runoff Control
(7-31)
Erosion and Sediment Control
(ESC) Plans (7-32)
Erosion Control Blankets (7-35)
Establish and Protect Stream
Buffers (7-37)
Fish Ladders(7-38)
Fish Lifts (7-40)
Flow Augmentation (7-41)
Fuel and Maintenance Staging
Areas (7-43)
Gated Conduits (7-44)
Groins (7-45)
Identify and Address NPS
Contributions (7-46)
Identify and Preserve Critical
Areas (7-48)
Joint Planting (7-50)
Labyrinth Weir (7-51)
Levees, Setback Levees, and
Floodwalls (7-52)
Channelization
8
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Live Cribwalls (7-54)
Live Fascines (7-56)
Live Staking (7-58)
Locate Potential Land
Disturbing Activities Away from
Critical Areas (7-60)
Marsh Creation and Restoration
(7-61)
Modifying Operational
Procedures (7-62)
Mulching (7-63)
Noneroding Roadways (7-64)
Pesticide and Fertilizer
Management (7-67)
Phase Construction (7-69)
Physical Barriers (7-70)
Pollutant Runoff Control (7-72)
Preserve Onsite Vegetation
(7-73)
Reregulation Weir (7-74)
Reservoir Aeration (7-75)
Retaining Walls (7-77)
Return Walls (7-78)
Revegetate (7-79)
Channelization
Physical & chemical
•
•
•
•
•
Instream/riparian restoration
•
•
•
•
•
•
Dams
Erosion control
•
•
•
•
•
•
•
•
•
•
Runoff control
•
•
•
Chemical/pollutant control
•
•
•
Watershed protection
Aerate reservoir water
•
Improve tailwater oxygen
•
•
Restore/maintain habitat
Maintain fish passage
•
Streambanks
Vegetative
•
•
•
Structural
•
Integrated
•
Planning & regulatory
Shorelines
Vegetative
•
Structural
•
Integrated
Planning & regulatory
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Revetment (7-80)
Riparian Improvements (7-82)
Riprap (7-83)
Root Wad Revetments (7-84)
Rosgen's Stream Classification
Method (7-86)
Scheduling Projects (7-88)
Sediment Basins/Rock Dams
(7-89)
Sediment Fences (7-91)
Sediment Traps (7-92)
Seeding (7-93)
Selective Withdrawal (7-94)
Setbacks (7-95)
Shoreline Sensitivity
Assessment (7-97)
Site Fingerprinting (7-99)
Sodding (7-1 00)
Soil Protection (7-101)
Spill and Water Budgets (7-102)
Spill Prevention and Control
Program (7-103)
Spillway Modifications (7-104)
Surface Roughening (7-105)
Channelization
Physical & chemical
•
•
•
•
•
Instream/riparian restoration
•
•
•
•
•
•
Dams
Erosion control
•
•
•
•
•
•
•
•
•
•
•
Runoff control
•
•
•
Chemical/pollutant control
•
Watershed protection
Aerate reservoir water
Improve tailwater oxygen
•
•
Restore/maintain habitat
•
•
Maintain fish passage
•
Streambanks
Vegetative
Structural
•
•
Integrated
•
•
Planning & regulatory
•
•
Shorelines
Vegetative
Structural
•
•
Integrated
•
Planning & regulatory
•
•
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Toe Protection (7-106)
Training— ESC (7-107)
Transference of Fish Runs
(7-108)
Tree Armoring, Fencing, and
Retaining Walls or Tree Wells
(7-109)
Tree Revetments (7-1 1 0)
Turbine Operation (7-112)
Turbine Venting (7-113)
Vegetated Buffers (7-114)
Vegetated Filter Strips (7-115)
Vegetated Gabions (7-116)
Vegetated Geogrids (7-118)
Vegetated Reinforced Soil
Slope (VRSS) (7-1 20)
Water Conveyances (7-121)
Wildflower Cover (7-1 22)
Wind Erosion Controls (7-123)
Wing Deflectors (7-1 24)
Channelization
8
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-------
Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Advanced Hydroelectric Turbines
Hydroelectric turbines can be designed to reduce impacts
to juvenile fish passing through the turbine as it operates.
Most research on advanced hydroelectric turbines is being
carried out by power producers in the Columbia River
basin (U.S. Army Corps of Engineers (USAGE) and public
utility districts) who are looking to improve the survival of
hydroelectric turbine-passed juvenile fish by modifying the
operation and design of turbines. Development of low
impact turbines is also being pursued on a national scale by
the U.S. Department of Energy (DOE) (Cada, 2001).
In the last few years, field studies have shown that
improvements in the design of turbines have increased the
survival of juvenile fish. Researchers continue to examine
the causes and extent of injuries from turbine systems, as
well as the significance of indirect mortality and the effects
of turbine passage on adult fish. Overall, improvements in turbine design and operation, and new
field, laboratory, and modeling techniques to assess turbine-passage survival, are contributing
towards improving downstream fish passage at hydroelectric power plants (Cada, 2001).
The redesign of conventional turbines for fish passage has focused on strategies to reduce
obstructions and to narrow the gaps between moveable elements of the turbine that are thought to
injure fish. The effects of changes in the number, size, orientation, or shape of the blades that
make up the runner (the rotating element of a turbine which converts hydraulic energy into
mechanical energy) are being investigated (Cada, 2001).
The USAGE has put considerable resources into improving turbine passage survival. The
USAGE Turbine Passage Survival Program (TSP) was developed to investigate means to
improve the survival of juvenile salmon as they pass through turbines located at Columbia and
Snake River dams. The TSP is organized along three functional elements that are integrated to
achieve the objectives (Cada, 2001):l
• Biological studies of turbine passage at field sites
• Hydraulic model investigations
• Engineering studies of the biological studies, hydraulic components, and optimization of
turbine operations
DOE supports development of low impact turbines under the Advanced Hydropower Turbine
System (AHTS) Program. The AHTS program explores innovative concepts for turbine design
that will have environmental benefits and maintain efficient electrical generation. The AHTS
program awarded contracts for conceptual designs of advanced turbines to different
firms/companies. Early in the development of conceptual designs, it became clear that there were
1 Additional information about USAGE efforts with advanced hydroelectric turbines is available at
http://hvdropower.inel.gov/turbines/pdfs/amfishsoc-fall2001.pdf.
EPA841-B-07-002
7-7
July 2007
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Chapter 7: Practices for Implementing Management Measures
significant gaps in the knowledge offish responses to physical stresses (injury mechanisms)
experienced during turbine passage. Consequently, the AHTS program expanded its activities to
include studies to develop biological criteria for turbines (Cada, 2001).2
2 Additional information about DOE efforts with advanced hydroelectric turbines is available at
http://hvdropower.inel.gov/rurbines/pdfs/amfishsoc-fall2001.pdf.
EPA841-B-07-002 7-8 July 2007
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Chapter 7: Practices for Implementing Management Measures
Bank Shaping and Planting
Bank shaping and planting involve regrading a streambank
to establish a stable slope angle, placing topsoil and other
material needed for plant growth on the streambank, and
selecting and installing appropriate plant species on the
streambank. This design is most successful on streambanks
where moderate erosion and channel migration are
anticipated. Reinforcement at the toe of the bank is often
required, particularly where flow velocities exceed the
tolerance range for plantings and where erosion occurs
below base flows. To determine the appropriate slope
angle, slope stability analyses that take into account
streambank materials, groundwater fluctuations, and bank
loading conditions are recommended (FISRWG, 1998).
Additional Resources
> FISRWG. 1998. Stream Corridor Restoration:
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Principles, Processes, and Practices. Federal Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Bank Shaping and Vegetating. Created for United
States Department of Agriculture, Natural Resource Conservation Service, Watershed Science
Institute. http://www.abe.rnsstate.edu/csd/NRCS-BMPs/pdf/strearns/bank/bankshapmg.pdf.
EPA841-B-07-002
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July 2007
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Chapter 7: Practices for Implementing Management Measures
Beach Nourishment
The creation or nourishment of existing beaches provides
protection to the eroding area and can also provide a
riparian habitat function, particularly when portions of the
finished project are planted with beach or dune grasses
(Woodhouse, 1978). Beach nourishment (Figures 7.1
through 7.4) requires a readily available source of suitable
fill material that can be effectively transported to the
erosion site for reconstruction of the beach (Hobson,
1977). Dredging or pumping from offshore deposits is the
method most frequently used to obtain fill material for
beach nourishment. A second possibility is the mining of
suitable sand from inland areas and overland hauling and
dumping by trucks. To restore an eroded beach and
stabilize it at the restored position, fill is placed directly
along the eroded sector (USAGE, 1984). In most cases,
plans must be made to periodically obtain and place additional fill on the nourished beach to
replace sand that is carried offshore into the zone of breaking waves or alongshore in littoral drift
(Houston, 1991; Pilkey, 1992).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
One important task that should not be
overlooked in the planning process for
beach nourishment projects is the proper
identification and assessment of the
ecological and hydrodynamic effects of
obtaining fill material from nearby
submerged coastal areas. Removal of
substantial amounts of bottom sediments in
coastal areas can disrupt populations of
fish, shellfish, and benthic organisms
(Atlantic States Marine Fisheries
Commission, 2002). Grain size analysis
should be performed on sand from both the
borrow area and the beach area to be
nourished. Analysis of grain size should
include both size and size distribution, and
fill material should match both of these
parameters (Stauble, 2005). Fill materials
should also be analyzed for the presence of
contaminants, and contaminated sediment
should not be used (CA Department of
Boating and Waterways and State Coastal
Conservancy, 2002). Turbidity levels in the
overlying waters can also be raised to
undesirable levels (EUCC, 1999). Certain
Dune
Nourishment
Figure 7.1 Dune Nourishment (CA Dept. of Boating and
Waterways and State Coastal Conservancy, 2002)
Design
Beach Width
Beach Width Lost Due To
Redistribution of Fill
Dry Beach Nourishment
(Initial Placement)
Sea
Stabilized Configuration
(After Redistribution of Fill)
Figure 7.2 Dry Beach Nourishment (CA Dept. of Boating
and Waterways and State Coastal Conservancy, 2002)
EPA841-B-07-002
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July 2007
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Chapter 7: Practices for Implementing Management Measures
areas may have seasonal restrictions on
obtaining fill from nearby submerged
areas (TRB, 2001). Timing of
nourishment activities is frequently a
critical factor since the recreational
demand for beach use frequently
coincides with the best months for
completing the beach nourishment.
These may also be the worst months
from the standpoint of impacts to
aquatic life and the beach community
such as turtles seeking nesting sites.
Design criteria should include proper
methods for stabilizing the newly
created beach and provisions for long-
term monitoring of the project to
document the stability of the newly
created beach and the recovery of the
riparian habitat and wildlife in the area.
Design
Beach Width~~\
Profile Nourishment
(Initial Placement)
Figure 7.3 Profile Nourishment (CA Dept. of Boating and
Waterways and State Coastal Conservancy, 2002)
Material Redistributed
by Waves and Currents
Nearshore Bar
Nourishment
(Initial Placement)
Figure 7.4 Nearshore Bar Nourishment (CA Dept. of Boating
and Waterways and State Coastal Conservancy, 2002)
Additional Resources
> Barber, D. No date. Beach
Nourishment Basics.
http: //www. brynmawr. edu/geolo gy/geomorph/beachnourishmentinfo. html.
^ NOAA. No date. Beach Nourishment: A Guide for Local Government Officials. U.S. Department
of Commerce, NOAA Coastal Services Center, http://www.csc.noaa.gov/beachnourishment.
> Scottish National Heritage. No date. A Guide to Managing Coastal Erosion in Beach/Dune
Systems: Beach Nourishment, http://www.snh.org.uk/publications/on-lme/
heritagemanagement/erosi on/appendix 1.7. shtml.
EPA841-B-07-002
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July 2007
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Chapter 7: Practices for Implementing Management Measures
Behavioral Barriers
Behavioral barriers use fish responses to external stimuli to
keep fish away from intakes or to attract them to a bypass.
Since fish behavior is notably variable both within and
among species, behavioral barriers cannot be expected to
prevent all fish from entering hydropower intakes.
Environmental conditions such as high turbidity levels can
obscure some behavioral barriers, such as lighting systems
and curtains. Competing behaviors such as feeding or
predator avoidance can also be a factor influencing the
effectiveness of behavioral barriers at a particular time.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Electric screens, bubble and chain curtains, light, sound,
and water jets have been evaluated in laboratory or field
studies and show mixed results. Despite numerous studies,
very few permanent applications of behavioral barriers
have been realized (EPRI, 1999). Some authors suggest
using behavioral barriers in combination with physical barriers (Mueller et al., 1999).
Electrical screens keep fish away from structures and guide them into bypass areas for removal.
Fish seem to respond to the electrical stimulus best when water velocities are low. Tests of an
electrical guidance system at the Chandler Canal diversion (Yakima River, Washington) showed
efficiency ranging from 70 to 84 percent for velocities of less than 1 ft/sec. Efficiencies
decreased to less than 50 percent when water velocities were higher than 2 ft/sec (Pugh et al.,
1971). Success of electrical screens may be specific to species and fish size. An electrical field
strength suitable to deter small fish may result in injury or death to large fish, since total fish
body voltage is directly proportional to fish body length (Stone and Webster, 1986). Electrical
screens require constant maintenance of electrodes and associated underwater hardware to
maintain effectiveness. Surface water quality can affect the life and performance of electrodes.
Bubble and chain curtains are created by pumping air through a diffuser to create a continuous,
dense curtain of bubbles, which can cause an avoidance response. Many factors affect fish
response to the curtains, including temperature, turbidity, light, and water velocity. Bubbler
systems should be constructed from corrosion-resistant materials and be installed with adequate
positioning of the diffuser away from areas where siltation might clog the air ducts. Hanging
chains provide a physical, visible obstacle that fish avoid. They are species-specific and
lifestage-specific. Efficiency of hanging chains is affected by such variables as velocity, instream
flow, turbidity, and illumination levels. Debris can limit their performance. In particular, buildup
of debris can deflect chains into a nonuniform pattern and disrupt hydraulic flow patterns.
Strobe lights repel fish by producing an avoidance response. A strobe light system at Saunders
Generating Station in Ontario, Canada was found to be 67 to 92 percent effective at repelling or
diverting eels (EPRI, 1999). Turbidity levels can affect strobe light efficiency. The intensity and
duration of the flash can also affect the response of the fish; for instance, an increase in flash
duration has been associated with less avoidance. Strobe lights have the potential for far-field
EPA841-B-07-002
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July 2007
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Chapter 7: Practices for Implementing Management Measures
fish attraction, since they can appear to fish as a constant light source due to light attenuation
over a long distance (Stone and Webster, 1986). Strobe lights at Hiram M. Chittenden Locks in
Seattle, Washington were examined to determine how fish respond, depending on strobe light
distance. Vertical avoidance was 90 to 100 percent when lights were 0.5 meters away, 45 percent
when 2.5 meters away, and 19 percent when 4.5 to 6.5 meters away (EPRI, 1999).
Mercury lights have successfully attracted fish to passage systems and repelled them from dams.
Studies suggest their effectiveness is species-specific; alewives (Alosapseudoharengus) were
attracted to mercury light, whereas coho salmon (Oncorhynchus kisutch) and rainbow trout
(Oncorhynchus mykiss) displayed no attraction to the light (Stone and Webster, 1986). In a test
on the Susquehanna River (Maryland, Pennsylvania, and New York), mercury lights attracted
gizzard shad (OTA, 1995). Although results have been mixed, low overall cost of the systems
has led to continued research on their effectiveness (Duke Engineering & Services, Inc., 2000).
Underwater sound, broadcast at different frequencies and amplitudes, has been effective in
attracting fish away from dams or repelling fish from dangers around dams, although the results
of field tests are not consistent. Fish have been attracted, repelled, or guided by the sound. A
study prepared for DOE showed that low-frequency, high particle motion was effective at
invoking flight and avoidance responses in salmonids (Mueller et al., 1998). These finding agree
with Knudsen et al. (1994), who found that low frequencies are efficient for evoking awareness
reactions and avoidance responses in juvenile Atlantic salmon. Not all fish possess the ability to
perceive sound or localized acoustical sources (Harris and Van Bergeijk, 1962). Fish also
frequently seem to become habituated to the sound source.
Poppers are pneumatic sound generators that create a high-energy acoustic output to repel fish.
Poppers have effectively repelled warm-water fish from water intakes. Laboratory and field
studies in California indicate avoidance by several freshwater species such as alewives (Alosa
pseudoharengus), perch, and smelt. Salmonids do not seem to be effectively repelled (Stone and
Webster, 1986). Operation and maintenance considerations include frequent replacement of "O"
rings, air entrainment in water inlets, and vibration of structures associated with the inlets.
Water jet curtains create hydraulic conditions that repel fish. Effectiveness is influenced by the
angle at which water is jetted. Although effectiveness averages 75 percent (Stone and Webster,
1986), not enough is known to determine what variables affect performance of water jet curtains.
Important operation and maintenance concerns would be clogging of the jet nozzles by debris or
rust and the acceptable range of stream flow conditions, which contribute to effective results.
Hybrid barriers or combinations of different barriers can enhance the effectiveness of individual
behavioral barriers. Laboratory studies showed a chain net barrier combined with strobe lights to
be up to 90 percent effective at repelling some species and sizes offish. Tests of combining rope-
net and chain-rope barriers have shown good results. Barriers with horizontal and vertical
components in the water column are more effective than those with vertical components alone.
Barriers with a large diameter are more effective than those with a small diameter, and thicker
barriers are more effective than thinner barriers. Effectiveness of hanging chains was increased
when used in combination with strobe lights. Effectiveness also increased when strobe lights
were added to air bubble curtains and poppers (Stone and Webster, 1986).
EPA841-B-07-002 7-13 July 2007
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Chapter 7: Practices for Implementing Management Measures
Branch Packing
Branch packing consists of alternating layers of live
branch cuttings and compacted backfill to repair small,
localized slumps and holes in slopes (Figure 7.5). Live
branch cuttings may range from 0.5 to 2 inches in
diameter. They should be long enough to touch
undisturbed soil at the back of the trench and extend
slightly outward from the rebuilt slope face. Wooden
stakes should be 5 to 8 feet long, depending on the depth
of the slump or hole being repaired. Stakes should also be
made from poles that are
3 to 4 inches in diameter or 2 by 4 feet lumber. Live posts
can be substituted. As plant tops begin to grow, the branch
packing system becomes more effective in retarding runoff
and reducing surface erosion. Trapped sediment refills the
localized slumps or holes, while roots spread throughout
the backfill and surrounding earth to form a unified mass.
Branch packing is not effective in slump areas greater than 4 feet deep or 5 feet wide (USDA-
NRCS, 1992). Installation guidelines are available from the USDA-FS Soil Bioengineering
Guide (USDA-FS, 2002) and the USDA Natural Resources Conservation Service's (NRCS's)
Engineering Field Handbook, Chapter 18 (USDA-NRCS, 1992).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Additional Resources
> FISRWG. 1998. Stream
Corridor Restoration:
Principles, Processes, and
Practices. Federal Interagency
Stream Restoration Working
Group.
http://www.nrcs.usda. gov/
technical/stream restoration/
PDFFILES/APPENDIX.pdf.
> ISU. 2006. How to Control
Streambank Erosion:
Branchpacking. Iowa State
University.
http ://www. ctre. iastate. edu/
erosion/manuals/streambank/
branchpacking.pdf.
BRANCH PACKING
Figure 7.5 Branch Packing (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Breakwaters
Breakwaters are wave energy barriers designed to protect
the land or nearshore area behind them from the direct
assault of waves. Breakwaters have traditionally been used
only for harbor protection and navigational purposes; in
recent years, however, designs of shore-parallel segmented
breakwaters have been used for shore protection purposes
(Fulford, 1985; Hardaway and Gunn, 1989; Hardaway and
Gunn, 1991; USAGE, 1990). Segmented breakwaters can
be used to provide protection over longer sections of
shoreline than is generally affordable through the use of
bulkheads or revetments. Wave energy is able to pass
through the breakwater gaps, allowing for the maintenance
of some level of longshore sediment transport, as well as
mixing and flushing of the sheltered waters behind the
structures. The cost per foot of shore for the installation of
segmented offshore breakwaters is generally competitive
with the costs of stone revetments and bulkheads (Hardaway
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
etal., 1991).
Figure 7.6 provides a view of breakwaters off the coast of Pennsylvania and Figure 7.7 illustrates
single and multiple breakwaters.
Figure 7.6 Breakwaters - View of Presque Isle, Pennsylvania (USAGE, 2003)
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Chapter 7: Practices for Implementing Management Measures
BREAKWATER
RESULTING SALIENT
ORIGINAL SHORELINE
ORIGINAL SHORELINE
Figure 7.7 Single and Multiple Breakwaters (USAGE, 2003)
Additional Resource
^ USAGE. No date. Breakwaters.
http://www.usna.edu/NAOE/courses/en420/bonnette/breakwater design.html.
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Brush Layering
Brush layering consists of placing live branch cuttings
interspersed between layers of soil on cut slopes or fill
slopes (Figures 7.8 and 7.9). These systems are
recommended on slopes up to 2:1 in steepness and not to
exceed 15 feet in vertical height. Branch cuttings, which
are placed in a crisscross or overlapping pattern, should be
long enough to reach the back of the bench and still
protrude from the bank (growing tips facing the outside of
the slope). The portions of the brush that protrude from the
slope face assist in retarding runoff and reducing surface
erosion. Backfill is then placed on the branches and
compacted.
Brush layering can be used to stabilize a slope against
shallow sliding or mass wasting, as well as to provide
erosion protection. Brush layers can stabilize and reinforce
the outside edge or face of drained earthen buttresses placed against cut slopes or embankment
fills. Brush layering works better on fill slopes than cut slopes, because much longer stems can
be used in fill (Mississippi State University, 1999). It is most applicable for areas subjected to cut
or fill operations or areas that are highly disturbed and/or eroded (ECY, 2007)
Brush layering is somewhat similar to live fascine systems because both involve the cutting and
placement of live branch cuttings on slopes. The two techniques differ principally in the
orientation of the branches and the depth to which they are placed in the slope. In brush layering,
the cuttings are oriented more or less perpendicular to the slope contour. In live fascine systems,
the cuttings are oriented more or less parallel to the slope contour. The perpendicular orientation
is more effective from the point of view of earth reinforcement and mass stability of the slope
(USDA-NRCS, 1992). Thus, brush
layering is more effective than live
fascines in terms of earth
reinforcement and mass stability
(Mississippi State University, 1999).
When used on a fill slope, brush
layering is similar to vegetated
geogrids, except the technique does
not use geotextile fabric (USDA-FS,
2002).
Brush layering can disrupt native
soils. Therefore, installation should
be completed in phases and no more
area should be excavated than is
necessary (ECY, 2007).
BRUSH LAYERING; PLAN VIEW
o
Back of
Figure 7.8 Brush Layering: Plan View (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Additional Resources
> Mississippi State University,
Center for Sustainable Design.
1999. Water Related Best
Management Practices in the
Landscape: Brush Layering.
Created for United States
Department of Agriculture,
Natural Resource Conservation
Service, Watershed Science
Institute.
http://www.abe.msstate.edu/
csd/NRCS-BMPs/pdf/streams/
bank/brushlayer.pdf
> Myers, RD. 1993. Slope
Stabilization and Erosion
Control Using Vegetation: A
BRUSH LAYERING: FILL METHOD
Figure 7.9 Brush Layering: Fill Method (USDA-FS, 2002)
Manual of Practice for Coastal Property Owners: Brush Layering. Shorelands and Coastal Zone
Management Program, Washington Department of Ecology. Olympia, WA. Publication 93-30.
http://www. ecy. wa. gov/programs/sea/pubs/93 -3 0/brush.html.
Walter, J., D. Hughes, and N.J. Moore. 2005. Streambank Revegetation and Protection: A Guide
for Alaska. Revegetation Techniques: Brush/Hedge - Brush Layering. Revised Edition. Alaska
Department of Fish and Game, Division of Sport Fish.
http ://www. sf. adfg. state, ak. us/S ARR/restoration/techniques/hedgebrush. cfm.
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Brush Mattressing
Brush mattressing is commonly used in Europe for
streambank protection (Figure 7.10). It involves digging a
slight depression on the bank and creating a mat or
mattress from woven wire or single strands of wire and
live, freshly cut branches from sprouting trees or shrubs.
Branches approximately 1 inch in diameter are normally
cut 6 to 9 feet long (the height of the bank to be covered)
and laid in criss-cross layers with the butts in alternating
directions to create a uniform mattress with few voids. The
mattress is then covered with wire secured with wooden
stakes 2.5 to 4 feet long. It is then covered with soil and
watered repeatedly to fill voids with soil and facilitate
sprouting; however, some branches should be left partially
exposed on the surface. The structure may require
protection from undercutting by placement of stones or
burial of the lower edge. Brush mattresses are generally
resistant to waves and currents and provide protection from the digging out of plants by animals.
Disadvantages include possible burial with sediment in some situations and difficulty in making
later plantings through the mattress.
Installation guidelines are available from the USDA-FS Soil Bioengineering Guide (USDA-FS,
2002). Under the Ecosystem Management and Restoration Research Program (EMRRP), the
USAGE has presented research on brush mattresses in a technical note (Brush Mattresses for
Streambank Erosion Control)3
Additional Resources
^ Allen, H.H. and C. Fischenich. 2001. Brush Mattresses for Streambank Erosion Control. U.S.
Army Corps of Engineers, Ecosystem Management and Restoration Research Program.
http://el.erdc.usace.army.mil/elpubs/pdf/sr23.pdf.
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda. gov/techmcal/stream_restoration/PDFFILES/APPENDIX.pdf.
> ISU. 2006. How to Control Streambank Erosion: Brushmattress. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/brushmattress.pdf.
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Brush Mattress. Created for United States Department
of Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/brushmattress.pdf.
3
http://el.erdc.usace.army.mil/elpubs/pdf/sr23.pdf
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July 2007
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Chapter 7: Practices for Implementing Management Measures
BRUSH MATTRESS
Dead
Stakes:
Mm. length
21/2'
Figure 7.10 Brush Mattress (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Bulkheads and Seawalls
Bulkheads (Figure 7.11) are primarily soil-retaining
structures designed to also resist wave attack. Seawalls are
principally structures designed to resist wave attack, but
they also may retain some soil (USAGE, 1984). Both
bulkheads and seawalls may be built of many materials,
including steel, timber, or aluminum sheet pile, gabions, or
rubble-mound structures. Although bulkheads and seawalls
protect the upland area against further erosion and land
loss, they often create a local problem. Downward forces
of water, produced by waves striking the wall, can produce
a transfer of wave energy and rapidly remove sand from
the wall (Pilkey and Wright, 1988). A stone apron is often
necessary to prevent scouring and undermining. With
vertical protective structures built from treated wood, there
are also concerns about the leaching of chemicals used in
the wood preservatives. Chromated copper arsenate
(CCA), the most
popular chemical used for
treating the wood used in
docks, pilings, and bulkheads,
contains elements of
chromium, copper, and arsenic
that are toxic above trace levels
(CSWRCB, 2005; Kahler et al.,
2000).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Additional Resources
> Scottish National Heritage.
No date. A Guide to
Managing Coastal Erosion
in Beach/Dune Systems:
Seawalls.
http://www.snh.org.uk/
publications/on-line/
heritagemanagement/
erosion/appendix 1.12.shtml.
> USACE. No date. Bulkheads
and Seawalls.
http: //www. usna. edu/NAOE/
Sheet Piliriq
pifmg
'-•Cellulor1 sheet
iling
Concrete
Slabs one
Kino-Pile
pile
" - Tongue™cnc™ groove
horizontal
concrete
slabs
Treated Tin&er
jntreoted Loqs
"X Anchor
..-.-JT*.
Figure 7.11 Typical Bulkhead Types (USACE, 2003)
courses/en420/bonnette/Seawall Design.html.
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Chapter 7: Practices for Implementing Management Measures
Check Dams
Check dams, a type of grade control structure, are small
dams constructed across an influent, intermittent stream, or
drainageway to reduce channel erosion by restricting flow
velocity. They can serve as emergency or temporary
measures in small eroding channels that will be filled or
permanently stabilized at a later date. Check dams can be
installed in eroding gullies as permanent measures that fill
up with sediment over time. In permanent usage, when the
impounded area is filled, a relatively level surface or delta
is formed over which water flows at a noneroding gradient.
The water then cascades over the dam through a spillway
onto a hardened apron. A series of check dams may be
constructed along a stream channel of comparatively steep
slope or gradient to create a channel consisting of a
succession of gentle slopes with cascades in between.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Check dams can be nonporous (constructed from concrete, sheet steel, or wet masonry) or porous
(using available materials such as straw bales, rock, brush, wire netting, boards, and posts).
Porous dams release part of the flow through the structure, decreasing the head of flow over the
spillway and the dynamic and hydrostatic forces against the dam. Nonporous dams are durable,
permanent, and more expensive, while porous dams are simpler, more economical to construct,
and temporary. Maintenance of check dams is important, especially the areas to the sides of the
dam. Regular inspections, particularly after high flow events, should be performed to observe
and repair erosion at the sides of the check dams. Excessive erosion could dislodge the check
dam, create additional channel erosion, and add more sediment to the streambed.
Additional Resources
^ CASQA. 2003. California Stormwater BMP Construction Handbook. Check Dams. California
Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/SE-4.pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Check Dam. Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/3.3 check dam.pdf.
^ Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Check Dam. Created for United States Department of
Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/water/erosion/checkdam.pdf.
> SMRC. No date. Stream Restoration: Grade Control Practices. The Stormwater Manager's
Resource Center.
http://www.stormwatercenter.net/Assorted%20F act%20Sheets/Restoration/grade_control. htm.
> Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Check Dams. Tennessee Department of Environment and Conservation, Nashville,
TN. http://state.tn.us/environment/wpc/sed ero controlhandbook/cd.pdf.
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Coconut Fiber Roll
The coconut fiber roll technique consists of cylindrical
structures composed of coconut husk fibers held together
with twine woven from coconut material (Figures 7.12 and
7.13). The fiber rolls are typically manufactured in 12-inch
diameters and lengths of 20 feet, which serves to protect
slopes from erosion, trap sediment, and as a result,
encourage plant growth within the fiber roll. The system is
typically installed near the toe of the streambank with
dormant cuttings and rooted plants inserted into holes cut
into the fiber rolls. Once installed, the system provides a
good substrate for promoting plant growth and is
appropriate where short-term moderate toe stabilization is
needed. Installation of this design requires minimal site
disturbance and is ideal for sites that are especially
sensitive to disturbance. A limitation of this system is that
it cannot withstand high velocities or large ice buildup, and
it can be fairly expensive to construct. Coconut fiber rolls have an effective life of 6 to 10 years.
In some locations, similar and abundant locally available materials, such as corn stalks, are being
used instead of coconut materials (FISRWG, 1998).
Installation guidelines are available from the USDA-
FS Soil Bioengineering Guide (USDA-FS, 2002).
Under EMRRP, the USAGE has presented research
on coconut rolls in a technical note (Coir Geotextile
Roll and Wetland Plants for Streambank Erosion
Control), which is available at
http://el.erdc.usace.army.mil/elpubs/pdf/sr04.pdf
Additional Resources
> CASQA. 2003. California Stormwater BMP
Construction Handbook: Fiber Rolls. California
Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/
Construction/SB-5 .pdf.
Figure 7.12 Coconut Fiber Roll
(Montgomery Watson, 2001)
FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
ISU. 2006. How to Control Streambank Erosion: Coconut Fiber Rolls. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/coconut fiber.pdf.
EPA841-B-07-002
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Chapter 7: Practices for Implementing Management Measures
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Coconut Fiber Roll. Created for United States
Department of Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/coconutFiberroll.pdf.
COCONUT FIBER ROLL
Existing vegetation, plantings, or
soil bioengineering techniques
Herbaceous Plug
OHW, or
Bankfull
Note: rooted, leafed
condition of plant
material \e> not
representative
of the time
of installation
Dead Stout Stakes
Figure 7.13 Coconut Fiber Roll (USDA-FS, 2002)
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July 2007
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Chapter 7: Practices for Implementing Management Measures
Collection Systems
Collection systems involve capture offish by screening
and/or netting followed with transport by truck or barge to
a downstream location. Since the late 1970s, the USAGE
has successfully implemented a program that takes juvenile
salmon from the uppermost dams in the Columbia River
system (Pacific Northwest) and transports them by barge or
truck to below the last dam. The program improves the
travel time offish through the river system, reduces most
of the exposure to reservoir predators, and eliminates the
mortality associated with passing through a series of
turbines (van der Borg and Ferguson, 1989). Survivability
rates for the collected fish are in excess of 95 percent, as
opposed to survival rates of about 60 percent when the fish
remain in the river system and pass through the dams
(Dodge, 1989). However, the collection efficiency can
range from 70 percent to as low as 30 percent. At the
McNary Dam on the Columbia River, spill budgets are also implemented to improve overall
passage (discussed in greater detail below) when the collection rate achieves less than 70 percent
efficiency (Dodge, 1989).
Additional Resource
> Chelan County Public Utility District. No date. Juvenile Fish Bypass.
http://www.chelanpud.org/iuvemle-fish-passage.html.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Construct Runoff Intercepts
Benches, terraces, or ditches break up a slope by providing
areas of low slope in the reverse direction. This keeps
water from proceeding down the slope at increasing
volume and velocity. Instead, the flow is directed to a
suitable outlet or protected drainage system. The frequency
of benches, terraces, or ditches will depend on the
erodibility of the soils, steepness and length of the slope,
and rock outcrops. This practice can be used if there is a
potential for erosion along the slope.
Earth dikes, perimeter dikes or swales, or diversions can
intercept and convey runoff from above disturbed areas to
undisturbed areas or drainage systems. An earth dike is a
temporary berm or ridge of compacted soil that channels
water to a desired location. A perimeter dike/swale or
diversion is a swale with a supporting ridge on the lower
side that is constructed from the soil excavated from the adjoining swale (Delaware DNREC,
2003). These practices can intercept flow from denuded areas or newly seeded areas and keep
clean runoff away from disturbed areas. The structures can be stabilized within 14 days of
installation. A pipe slope drain, also known as a pipe drop structure, is a temporary pipe placed
from the top of a slope to the bottom of the slope to convey concentrated runoff down the slope
without causing erosion (Delaware DNREC, 2003).
Additional Resources
^ CASQA. 2003. California Stormwater BMP Construction Handbook. Earth Dikes and Drainage
Swales. California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/EC-9.pdf.
> Fifield, J. 2000. Design and Implementation of Runoff Control Structures: Diversion Dikes and
Swales, http://www.forester.net/ec 0001 design.html#diversion.
^ Lake Superior/Duluth Streams. 2005. Grassed Swales.
http://www.duluthstreams.org/stormwater/toolkit/swales.html.
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Chapter 7: Practices for Implementing Management Measures
Constructed Spawning Beds
When a dam adversely affects the aquatic habitat of an
anadromous fish species, one option may be to construct
replacement spawning beds. Additional facilities such as
electric barriers, fish ladders, or bypass channels would be
required to channel the fish to these spawning beds.
Merz et al., (2004) tested whether spawning bed
enhancement increases survival and growth of Chinook
salmon (Oncorhynchus tshawytschd) embryos in a
regulated stream with a gravel deficit. The authors also
examined a dozen physical parameters correlated with
spawning sites (e.g., stream velocity, average turbidity,
distance from the dam) and how they predicted survival
and growth of Chinook salmon and steelhead
(Oncorhynchus mykiss). The results suggest that spawning
bed enhancement can improve embryo survival in
degraded habitat. Measuring observed physical parameters before and after spawning bed
manipulation can also accurately predict benefits. The National Oceanic and Atmospheric
Administration's (NOAA's) Status Review of Chinook Salmon from Washington, Idaho, Oregon,
and California (1998) states that artificial spawning beds for ocean-type Chinook salmon
operated near three different dams was discontinued because of high pre-spawning mortality in
adult fish and poor egg survival in the spawning beds. Success of constructed spawning beds in
increasing survival and development offish varies and often depends on the site.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
0 Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Construction Management
Construction areas can be managed properly to control
erosion by stabilizing entrances and proper traffic routing.
A construction entrance is a pad of gravel or rock over
filter cloth located where traffic enters and leaves a
construction site. As construction vehicles drive over the
gravel, mud and sediment are collected from the vehicles'
wheels. To maximize effectiveness, the rock pad should be
at least 50 feet long and 10 to 12 feet wide. The gravel
should be 1- to 2-inch aggregate 6 inches deep laid over a
layer of filter fabric. Maintenance might include pressure
washing the gravel to remove accumulated sediment and
adding more rock to maintain thickness. Runoff from this
entrance should be treated before exiting the site. This
practice can be combined with a designated truck wash-
down station to ensure sediment is not transported off-site.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Where possible, construction traffic should be directed to avoid existing or newly planted
vegetation. Instead, it should be directed over areas that must be disturbed for other construction
activity. This practice reduces the net total area that is cleared and susceptible to erosion.
Additional Resources
> CASQA. 2003. California Stormwater BMP Construction Handbook. Stabilized Construction
Entrance/Exit. California Stormwater Quality Association, Sacramento, CA.
http://www. cabmphandbooks.com/Documents/Construction/TR-1 .pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Stabilized Construction Entrance.
Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/3.14 stabilized entrance.pdf.
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Chapter 7: Practices for Implementing Management Measures
Dormant Post Plantings
Dormant post plantings include planting of either
cottonwood, willow, poplar, or other sprouting species
embedded vertically into streambanks to increase channel
roughness, reduce flow velocities near the slope face, and
trap sediment (Figure 7.14). Dormant posts are made up of
large cuttings installed in streambanks in square or
triangular patterns. Live posts should be 7 to 20 feet long
and 3 to 5 inches in diameter. This method is effective for
quickly establishing riparian vegetation particularly in arid
regions. By decreasing near bank flow velocities, this
design causes sediment deposition and reduces streambank
erosion. This design is more resistant to erosion than live
staking or similar designs that use smaller cuttings.
Success of this design is most likely on streambanks that
are not gravel dominated and where ice build up is not
common. The exclusion of certain herbivores aids in the
success of this design. This method should be combined with other soil
bioengineering techniques to achieve a comprehensive streambank restoration design (FISRWG,
1998). Installation guidelines are available from the USDA-FS Soil Bioengineering Guide
(USDA-FS, 2002).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Additional Resources
> FISRWG. 1998.
Stream Corridor
Restoration:
Principles, Processes,
and Practices.
Federal Interagency
Stream Restoration
Working Group.
http://www.nrcs.usda.
gov/technical/
stream restoration/
PDFFILES/
APPENDIX.pdf.
> ISU. 2006. How to
Control Streambank
Erosion: Dormant
Post Plantings. Iowa
State University.
LIVE POSTS
(Nci i
Triangular Spacing
of Posts
Existing vegetation,
plantings, or soil
Live Posts:
7-20' iong, 3"-6" diameter;
Posts should extend
to dry season water level
2:1 to 5:1 Slope
or oo
Dry Season Water Level
Figure 7.14 Live Posts (USDA-FS, 2002)
http://www.ctre.iastate.edu/erosion/manuals/streambank/dormant post.pdf.
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Chapter 7: Practices for Implementing Management Measures
Encourage Drainage Protection
A complete understanding of watershed protection should
include the implementation of practices that guide future
development and land use activities. This will not only
help to identify existing sources of NFS pollution but also
to prevent future impairments that may impact dam
construction or operations and reservoir management.
Watershed protection practices can include zoning for
natural resource protection. Several zoning techniques are:
• Use cluster zoning and planned unit development
• Consider resource protection zones
• Practice performance-based zoning
• Establish overlay zones
• Establish bonus or incentive zoning
• Consider large lot zoning
• Practice agricultural protection zoning
• Use watershed-based zoning
• Delineate urban growth boundaries
More details about these techniques and case studies can be found in Protecting Wetlands: Tools
for Local Governments in the Chesapeake Bay Region (Chesapeake Bay Program, 1997).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
0 Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Equipment Runoff Control
During construction and maintenance activities at dams,
equipment and machinery can be a potential source of
pollution to the surface and ground water. Thinners or
solvents should not be discharged into sanitary or storm
sewer systems or into surface water systems, when
cleaning machinery. Use alternative methods for cleaning
larger equipment parts, such as high-pressure,
high-temperature water washes or steam cleaning.
Equipment-washing detergents can be used and wash water
appropriately discharged. Small parts should be cleaned
with degreasing solvents that can be reused or recycled.
Washout from concrete trucks should never be dumped
directly into surface waters or into a drainage leading to
surface waters but can be disposed of into:
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
0 Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
A designated area that will later be backfilled
An area where the concrete wash can harden, can be broken up, and can then be
appropriately disposed
A location not subject to surface water runoff and more than 50 feet away from a
receiving water
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
D Integrated
0 Planning & regulatory
Erosion and Sediment Control (ESC) Plans
ESC plans are important for controlling the adverse
impacts of dam construction. ESC plans ensure that
provisions for control measures are incorporated into the
site planning stage of development. ESC plans also provide
for prevention of erosion and sediment problems and
accountability if a problem occurs (MDEP, 1990). In many
municipalities, ESC plans are required under ordinances
enacted to protect water resources. These plans describe
the activities construction and maintenance personnel will
use to reduce soil erosion and contain and treat runoff that
is carrying eroded sediments. ESC plans typically include
descriptions and locations of soil stabilization practices,
perimeter controls, and runoff treatment facilities that will
be installed and maintained before and during construction
activities. In addition to special area considerations, the full
ESC plan review inventory should include:
• Topographic and vicinity maps
• Site development plan
• Construction schedule
• Erosion and sedimentation control plan drawings
• Detailed drawings and specifications for practices
• Design calculations
• Vegetation plan
• Detailed drawings and specifications for control or management practices
Some erosion and soil loss is unavoidable during land-disturbing activities. Although proper
siting and design help prevent areas prone to erosion from being developed, construction
activities invariably produce conditions where erosion can occur. To reduce the adverse impacts
associated with construction activities at dams, the construction management measure suggests a
system of nonstructural and structural ESCs for incorporation into an ESC plan.
Nonstructural controls address erosion control by decreasing erosion potential, whereas
structural controls are both preventive and mitigative because they control erosion and sediment
movement. Brown and Caraco (1997) identified several general objectives that should be
addressed in an effective ESC plan:
• Minimize clearing and grading - clearing and grading should occur only where
absolutely necessary to build and provide access to structures and infrastructure. Clearing
should be done immediately before construction, rather than leaving soils exposed for
months or years (SQI, 2000).
• Protect waterways and stabilize drainage ways - all natural waterways within a
development site should be clearly identified before construction activities begin.
Clearing should generally be prohibited in or adjacent to waterways. Sediment control
EPA841-B-07-002
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Chapter 7: Practices for Implementing Management Measures
practices such as check dams might be needed to stabilize drainage ways and retain
sediment on-site.
• Phase construction to limit soil exposure - construction phasing is a process where only a
portion of the site is disturbed at any one time to complete the required building in that
phase. Other portions of the site are not cleared and graded until exposed soils from the
earlier phase have been stabilized and the construction nearly completed.
• Stabilize exposed soils immediately - seeding or other stabilization practices should occur
as soon as possible after grading. In colder climates, a mulch cover is needed to stabilize
the soil during the winter months when grass does not grow or grows poorly.
• Protect steep slopes and cuts - wherever possible, clearing and grading of existing steep
slopes should be completely avoided. If clearing cannot be avoided, practices should be
implemented to prevent runoff from flowing down slopes.
• Install perimeter controls to filter sediments - perimeter controls are used to retain
sediment-laden runoff or filter it before it exits the site. The two most common perimeter
control options are silt fences and earthen dikes or diversions.
• Employ advanced sediment-settling controls - traditional sediment basins are limited in
their ability to trap sediments because fine-grained particles tend to remain suspended
and the design of the basin themselves is often simplistic. Sediment basins can be
designed to improve trapping efficiency through the use of perforated risers; better
internal geometry; the installation of baffles, skimmers, and other outlet devices; gentler
side slopes; and multiple-cell construction.
ESC plans ensure that provisions for control measures that are incorporated into the site planning
stage of development help to reduce the incidence of erosion and sediment problems, and
improve accountability if a problem occurs. An effective plan for runoff management on
construction sites controls erosion, retains sediments on-site to the extent practicable, and
reduces the adverse effects of runoff. Climate, topography, soils, drainage patterns, and
vegetation affect how erosion and sediment should be controlled on a site (Washington State
Department of Ecology, 1989).
ESC plans should be flexible to account for unexpected events that occur after the plans have
been approved, including:
• Discrepancies between planned and as-built grades
• Weather conditions
• Altered drainage
• Unforeseen construction requirements
Changes to an ESC plan should be made based on regular inspections that identify whether the
ESC practices were appropriate or properly installed or maintained. Inspecting an ESC practice
after storm events shows whether the practice was installed or maintained properly. Such
inspections also show whether a practice requires cleanout, repair, reinforcement, or replacement
with a more appropriate practice. Inspecting after storms is the best way to ensure that ESC
practices remain in place and effective at all times during construction activities.
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Chapter 7: Practices for Implementing Management Measures
Because funding for ESC programs is not always dedicated, budgetary and staffing constraints
may thwart effective program implementation. Brown and Caraco (1997) recommend several
management techniques to ensure that ESC programs are properly administered:
• Local leadership committed to the ESC program
• Redeployment of existing staff from the office to the field or training room
• Cross-training of local review and inspection staff
• Submission of erosion prevention elements for early planning reviews.
• Prioritization of inspections based on erosion risk
• Requirement of designers to certify the initial installation of ESC practices
• Investment in contractor certification and private inspector programs
• Use of public-sector construction projects to demonstrate effective ESC controls
• Enlistment of the talents of developers and engineering consultants in the ESC program
• Revision and update of the local ESC manual
An allowance item that acts as an additional "insurance policy" for complying with the erosion
and sediment control plan can be added to bid or contract documents (Deering, 2000a). This
allowance covers costs to repair storm damage to ESC measures as specified in the ESC plan.
This allowance does not cover storm damage to property that is not related to the ESC plan,
because this would be covered under traditional liability insurance. Damage caused by severe
and continuous rain events, windblown objects, fallen trees or limbs, or high-velocity, short-term
rain events on steep slopes and existing grades would be covered by the allowance, as would
deterioration from exposure to the elements or excessive maintenance for silt removal. The
contractor is responsible for being in compliance with the ESC plan by properly implementing
and maintaining all specified measures and structures. The allowance does not cover damage to
practices caused by improper installation or maintenance.
Additional Resources
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Infiltration Basin and Trench. Iowa
State University. http://www.ctre.iastate.edU/erosion/manuals/construction/4.l infiltration.pdf.
> Milwaukee River Basin Partnership. 2003. Detention & Infiltration Basins.
http://clean-water.uwex.edu/plan/drbasins.htm.
> Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Vegetative Practices. Tennessee Department of Environment and Conservation,
Nashville, TN.
http://state.tn.us/environment/wpc/sed ero controlhandbook/2.%20Vegetative%20Practices.pdf.
EPA841-B-07-002 7.34 July 2007
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Erosion Control Blankets
Turf reinforcement mats (TRMs) combine vegetative
growth and synthetic materials to form a high-strength mat
that helps prevent soil erosion in drainage areas and on
steep slopes (Figure 7.15) (USEPA, 1999). TRMs enhance
vegetation's natural ability to protect soil from erosion.
They are composed of interwoven layers of nondegradable
geosynthetic materials (e.g., nylon, polypropylene) stitched
together to form a three-dimensional matrix. They are thick
and porous enough to allow for soil filling and retention. In
addition to providing scour protection, the mesh netting of
TRMs is designed to enhance vegetative root and stem
development. By protecting the soil from scouring forces
and enhancing vegetative growth, TRMs can raise the
threshold of natural vegetation to withstand higher
hydraulic forces on stabilization slopes, Streambanks, and
channels. In addition to reducing flow velocities, natural vegetation removes particulates through
sedimentation and soil infiltration and improves site aesthetics. In general, TRMs should not be
used for the following:
• To prevent deep-seated slope failure due to causes other than surficial erosion
• If anticipated hydraulic conditions are beyond the limits of TRMs and natural vegetation
• Directly beneath drop outlets to dissipate impact force (can be used beyond impact zone)
• Where wave height might exceed 1 foot (can protect areas upslope of wave impact zone)
The performance of a TRM-lined conveyance system
depends on the duration of the runoff event. For
short-term events, TRMs are typically effective at
flow velocities of up to 15 feet per second and shear
stresses of up to 8 Ib/ft2. However, specific high-
performance TRMs may be effective under more
severe hydraulic conditions. Practitioners should
check with manufacturers for specifications and
performance limits of different products. Factors
influencing the cost of TRMs include the type of
material required, site conditions (e.g., underlying
soils, slope steepness), and installation-specific
factors (e.g., local construction costs). TRMs
typically cost considerably less than concrete and
riprap solutions.
Figure 7.15 Erosion Control Blanket
(Conwed Fibers, n.d.)
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Chapter 7: Practices for Implementing Management Measures
Additional Resources
^ Barr Engineering Company. 2001. Minnesota Urban Small Sites BMP Manual: Stormwater Best
Management Practices for Cold Climates. Soil Erosion Control: Mulches, Blankets and Mats.
Prepared for the Metropolitan Council by Barr Engineering Company, St. Paul, MN.
http://www.metrocouncil.org/EnvironmentAVatershed/BMP/CH3 RPPSoilMulch.pdf.
> CASQA. 2003. California Stormwater BMP Construction Handbook: Geotextiles and Mats.
California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/EC-7.pdf
^ California Department of Transportation. \999.SoilStabilization Using Erosion Control
Blankets. Construction Storm Water Pollution Prevention Bulletin. Vol. 3, No. 8. California
Department of Transportation, Division of Environmental Analysis, Sacramento, CA.
http://www.dot.ca.gov/hq/env/stormwater/publicat/const/Aug 1999.pdf
> Matthews, M. 1998. What are RECPs? Soil Stabilization Using Erosion Control Blankets.
Erosion Control Technology Council, St. Paul, MN. http://www. ectc. org/what.html.
> North American Green. 2004. Green Views: Turn Reinforcement Mats as an Alternative to Rock
Riprap. North American Green, Evansville, IN.
http://www.nagreen.com/resources/literature/GV AltToRockRiprap.pdf
> Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Vegetative Practices: Erosion Control Blanket/Matting. Tennessee Department of
Environment and Conservation, Nashville, TN.
http://state.tn.us/environment/wpc/sed ero controlhandbook/2.%20Vegetative%20Practices.pdf
EPA841-B-07-002 7.36 July 2007
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Chapter 7: Practices for Implementing Management Measures
Establish and Protect Stream Buffers
Riparian buffers and wetlands can provide long-term
pollutant removal capabilities without the comparatively
high costs usually associated with constructing and
maintaining structural controls. Conservation or
preservation of these areas is important to water quality
protection. Land acquisition programs help to preserve
areas considered critical to maintaining surface water
quality. Adequate buffer strips along streambanks provide
protection for stream ecosystems, help stabilize the stream,
and can prevent streambank erosion (Holler, 1989). Buffer
strips can also protect and maintain near-stream vegetation
that attenuates the release of sediment into stream
channels. Levels of suspended solids have been shown to
increase at a slower rate in stream channel sections with
well-developed riparian vegetation (Holler, 1989).
Channelization
D Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
0 Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
0 Planning & regulatory
Stream buffers should be protected and preserved as a conservation area because these areas
provide many important functions and benefits, including:
• Providing a "right-of-way" for lateral movement
• Conveying floodwaters
• Protecting streambanks from erosion
• Treating runoff and reducing drainage problems from adjacent areas
• Providing nesting areas and other wildlife habitat functions
• Mitigating stream warming
• Protecting wetlands
• Providing recreational opportunities and aesthetic benefits
• Increasing adjacent property values
Specific stream buffer practices could include:
• Establishing a stream buffer ordinance
• Developing vegetative and use strategies within management zones
• Establishing provisions for stream buffer crossings
• Integration of structural runoff management practices where appropriate
• Developing stream buffer education and awareness programs
More information on establishing and protecting stream buffers is available from EPA's National
Management Measures to Control Nonpoint Source Pollution from Urban Areas,4 a document
for use by state, local, and tribal managers in the implementation of nonpoint source pollution
management programs. It contains a variety of practices and management activities for reducing
pollution of surface and ground water from urban areas (USEPA, 2005d).
'http://www.epa.gov/owow/nps/urbanmm/index.html
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Chapter 7: Practices for Implementing Management Measures
Fish Ladders
Fish ladders have been a commonly used structure to
enable the safe upstream and downstream passage of
mature fish (see Figure 7.16). There are four basic
designs: pool-weir, Denil, vertical slot, and steeppass.
Pool-weir fish ladders are one of the oldest and most
commonly designed fish passage structures, which
consists of stepped pools and weirs that allow fish to pass
from pool to pool over the weirs that separate each. Pool-
weir fish ladders are normally used on slopes of about 10-
degrees. Some pool-weir fish ladders can be modified to
increase the possible number offish that are passed by
including submerged orifices that allow fish to pass the
fish ladder without cresting the weirs.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Pool-weir fish ladders will pass many different species of
fish if they are designed correctly for the environment in which they are employed. OTA (1995)
provides details on design and operation of various forms offish ladders.
Figure 7.16 Fish Ladder at Feather River Hatchery, Oroville Dam, CA (Feather River, n.d.)
Denil fish ladders are elongated rectangular channels that use internal baffles to dissipate flow
energy and allow fish passage. They are widely used in the eastern United States due to their
ability to pass a wide range of species (from salmonids to riverine) over a wider range of flows
than pool-weir ladders. Denil ladders can be used on slopes from 10 to 25 degrees although 10 to
15 degrees is optimal. Most Denil fish ladders are 2-4 feet wide and 4-8 feet deep. This fish
ladder design allows fish to pass at a preferred depth instead of through a jumping action. Denil
ladders do not have resting areas and therefore fish must either be able to pass the ladder in one
burst or resting pools must be provided between sections. Resting pools should be provided
every 16 to 50 feet depending upon the species being passed. The high flow rates and turbulence
EPA841-B-07-002
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Chapter 7: Practices for Implementing Management Measures
associated with Denil fish ladders reduces the demand for attraction flow, which is commonly
added to insure good attraction over varying flow rates.
Vertical slot fish ladders are elongated rectangular channels that use regularly spaced baffles to
create steps and resting pools. The vertically oriented slots in the baffles allow fish to pass
through the ladder at a preferred depth. Unlike Denil fishways, vertical slot fishways provide a
resting area behind each baffle allowing fish to pass in a "burst-rest" manner instead of one
sustained motion. The channel created by the baffles is off-center making the baffles on one side
of the ladder wider than the opposing side. Eddies that form behind longer baffles allow fish to
rest and end the need for resting areas. Although vertical slot ladders are usually operated at
slopes of about 10 degrees, they can be operated over a larger variety of flows. The vertical slots
create a water jet that is regulated by the pool on the downstream side of it. This creates a
uniform, level flow throughout the ladder.
The steeppass fish ladder, often referred to as the "Alaska steeppass," is a modified Denil fish
ladder most commonly used in remote areas for the passage of salmonids. Steeppass fish ladders
are usually constructed of lightweight materials such as aluminum and can operate on slopes up
to 33 percent. The construction materials and design allow this type offish ladder to be deployed
as a single unit to remote areas. The baffles used in steeppass ladders are more aggressively
designed, which allow the ladder to more effectively control water flow. The steeppass ladder is
not without its limitations. Due to their narrow design, steeppass ladders are more susceptible to
clogging due to debris and changes in flow upstream or downstream of the ladder.
Although fish ladders can be extremely efficient at passing fish, small changes in design have
been shown to significantly improve their functionality. A good example of this is the John Day
Dam located on the Columbia River. The original design focused on the passage of salmonids
and therefore only passed about 17 percent of the American shad (Alosa sapidissima) using the
ladder. Research indicated that simple design changes could allow for the passage of riverine
species such as American shad. By changing the placement of the weirs within the fish ladder,
the fish ladder was able to pass 94 percent of the salmonids, and American shad passage
increased to 74 percent (Monk et al., 1989).
According to the USAGE, Portland District (1997), the success rate for adults negotiating fish
ladders at dams in the Columbia River Basin is about 95 percent. The U.S. Fish and Wildlife
Agency designs fishways assuming a 90 percent efficiency rate. Few studies document actual
efficiency offish ladders, but it is recognized that not all fishways are equally effective (for
various reasons, such as predation or physical damage to passing fish). Some fishways installed
in the last 20 years are less effective than newer ones (when federal licenses began to include
fish passage requirements). Maine Department of Marine Resources (DMR) estimates efficiency
between 75 and 90 percent (Presumpscot River Plan Steering Committee, 2002).
Additional Resource
> Michigan DNR. No date. What is a fish ladder? Michigan Department of Natural Resources,
Lansing, MI. http://www.michigan.gov/dnr/OJ607.7-153-10364 19092-46291-.00.html.
EPA841-B-07-002 7.39 July 2007
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Chapter 7: Practices for Implementing Management Measures
Fish Lifts
Fish lifts describe both fish elevators and locks, which are
used to capture fish at the downstream side of a structure
and then move them above the structure. Like fish ladders,
these systems require sufficient attraction flow to move
fish into the lift area. Lift systems can be advantageous
because they are not species or flow specific. They can
also be employed at structures too tall for fish ladders and
to pass species with reduced swimming ability.
Lift systems have the potential to move large numbers of
fish if they are operated efficiently. These systems can be
automated to allow operation much like fish ladders. Fish
lift systems do require additional operation and
maintenance costs and are subject to mechanical failures
not associated with fish ladders.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Most lift systems require either an active or passive bypass system to move fish far enough
upstream to avoid entrainment in the flow through the dam. Passive bypass systems may include
constructed waterways or pipes that discharge passed fish sufficiently up-steam of the structure.
Active bypass systems include trucking and pumping operations that discharge the fish safely
upstream of the structure. Active bypass systems, especially pumping systems, have come under
scrutiny for fish behavior and health reasons. During the pumping process, fish may be subject to
descaling and/or death due to overcrowding. After release, the fish may have orientation
problems and therefore be subject to higher rates of predation mortality. Due to these concerns
the United States Fish and Wildlife service has generally opposed the use offish pumps (OTA,
1995).
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
0 Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Flow Augmentation
Operational procedures such as flow regulation, flood
releases, or fluctuating flow releases all have the potential
for detrimental impacts on downstream aquatic and
riparian habitat. When evaluating solutions associated with
degraded aquatic and riparian habitat, stakeholders must
balance operational procedures to address the needs of
downstream aquatic and riparian habitat with the
requirements of dam operation. There are often legal and
jurisdictional requirements for an operational procedure at
a particular dam that should also be considered (USDOI,
1988).
A flushing flow is a high-magnitude, short-duration release
for the purpose of maintaining channel capacity and the
quality of instream habitat by scouring the accumulation of
fine-grained sediments from the streambed. Availability of
suitable instream habitat is a key factor limiting spawning success. Flushing flows wash away
the sediments without removing the gravel. Flushing flows also prevent the encroachment of
riparian vegetation.
However, it is important to keep in mind that flushing flows are not recommended in all cases.
Flushing flows of a large magnitude may cause flooding in the old floodplain or depletion of
gravel below a dam. Flushing flows are more efficient and predictable for small, shallow, high-
velocity mountain streams unaltered by dams, diversions, or intensive land use. Routine
maintenance generally requires a combination of practices including high flows coupled with
sediment dams or channel dredging, rather than simply relying on flushing or scouring flows
(Nelson et al., 1988).
Several options exist for creating minimum flows in the tailwaters below dams. The selection of
any particular technique as the most cost-effective is site-specific and depends on several factors
including adequate performance to achieve the desired instream and riparian habitat
characteristic, compatibility with other requirements for operation of the hydropower facility,
availability of materials, and cost.
Sluicing is the practice of releasing water through the sluice gate rather than through the turbines.
For portions of the waterway immediately below the dam, the steady release of water by sluicing
provides minimum flows with the least amount of water expenditure. At some facilities, this
practice may dictate that modifications be made to the existing sluice outlets to maintain
continuous low releases. Continuous low-level sluice releases at Eufala Lake and Fort Gibson
Lake (Oklahoma) provided minimum flows needed to sustain downstream fish populations. The
sluicing also had the benefit of improving DO levels in tailwaters downstream of these two dams
such that fish mortalities, which had been experienced in the tailwaters below these two dams
prior to initiating this practice, no longer occurred (USDOE, 1991).
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Chapter 7: Practices for Implementing Management Measures
Turbine pulsing is a practice involving the release of water through the turbines at regular
intervals to improve minimum flows. In the absence of turbine pulsing, water is released from
large hydropower dams only when the turbines are operating, which is typically when the
demand for power is high.
A study undertaken at the Douglas Dam (French Broad River, Tennessee) suggests some of the
site-specific factors that should be considered when evaluating the advantages of practices such
as turbine pulsing, sluicing, or other alternatives for providing minimum flows and improving
dissolved oxygen (DO) levels in reservoir releases. Two options for maintaining minimum flows
(turbine pulsing and sluicing), and two aeration alternatives (operation of surface water pumps
and diffusers) were evaluated for their effectiveness, advantages, and disadvantages in providing
minimum flows and aeration of reservoir releases. Computer modeling indicated that either
turbine pulsing or sluicing could improve DO concentrations in releases by levels ranging from
0.7 to 1.5 mg/L. This is slightly below the level of improvement that might be expected from
operation of a diffuser system for aeration. A trade-off can also be expected at this facility
between water saved by frequent short-release pulses and the higher maintenance costs due to
operating turbines on and off frequently (Hauser et al., 1989). Hauser et al. (1989) found that
schemes of turbine pulsing ranging from 15-minute intervals to 60-minute intervals every 2 to 6
hours were found to provide fairly stable flow regimes after the first 3 to 8 miles downstream at
several Tennessee Valley Authority (TVA) projects. However, at points farther downstream, less
overall flow would be produced by sluicing than by pulsing. Turbine pulsing may also cause
waters to rise rapidly, which could endanger people wading or swimming in the tailwaters
downstream of the dam (TVA, 1990).
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Chapter 7: Practices for Implementing Management Measures
Fuel and Maintenance Staging Areas
Proper maintenance of equipment and installation of
proper stream crossings will further reduce pollution of
water by these sources. Vehicles need to be inspected for
leaks. To prevent runoff, fuel and maintain vehicles on site
only in a bermed area or over a drip pan. Fuel tanks should
be protected and have containment systems. Stream
crossings can be minimized through proper planning of
access roads. This will help to keep potential sources of
pollution away from direct contact with surface waters.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
0 Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Gated Conduits
Gated conduits are hydraulic structures that divert the flow
of water under the dam. They are designed to create
turbulent mixing to enhance oxygen transfer. Gates are
used to control the cross-sectional area of flow. Gated
conduits have been extensively analyzed for their
performance and effectiveness (Wilhelms and Smith,
1981), although the available data are mostly from high-
head projects (Wilhelms, 1988). An example of the
effectiveness found that gated conduit structures were able
to achieve 90 percent aeration and a minimum DO
standard of 5 mg/L (Wilhelms and Smith, 1981).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Tuned
T-Shape
T-Shaped
Groins
Groins are structures that are built perpendicular to the
shore and extend into the water. Examples of possible
planform shapes for groins are illustrated in Figure 7.17.
They are generally constructed in series, referred to as a
groin field, along the entire length of shore to be protected.
Groins trap sand in littoral drift and halt its longshore
movement along beaches. The sand trapped by each groin
acts as a protective barrier that waves can attack and erode
without damaging previously unprotected upland areas.
Unless the groin field is artificially filled with sand from
other sources, sand is trapped in each groin by interrupting
the natural supply of sand moving along the shore in the
natural littoral drift. This frequently results in an
inadequate natural supply of sand to replace the sand
carried away from beaches located farther along the shore
in the direction of the littoral drift. If "downdrift" beaches
are kept starved of sand
for long periods of time,
severe beach erosion in
unprotected areas can
result. As with bulkheads
and revetments, the most
durable materials for
construction of groins are
timber and stone. Less
expensive techniques for
building groins use sand-
or concrete-filled bags or
tires. It must be
recognized that the use of
lower-cost materials in
the construction of
bulkheads, revetments, or
groins frequently results
in less durability and
reduced project life.
Figure 7.18 illustrates
transition from a groin
field to a natural
shoreline.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Straight
Inclined
L-Shaped
Dogleg
Y-Shaped or
Fishtail
Figure 7.17 Possible Planform Shapes for Groins (USAGE, 2003)
Figure 7.18 Transition from Groin Field to Natural Shoreline (USAGE, 2003)
Additional Resource
> USAGE. No date. Groins. U.S. Army Corps of Engineers, Coastal & Hydraulics Laboratory.
http://chl.erdc.usace.armv.mil/chl.aspx?p=s&a=ARTICLES!188.
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Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
0 Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Identify and Address NFS Contributions
Another watershed protection practice involves the
evaluation of the total NFS pollution contributions in the
watershed. NFS contributions can stem from different
land use activities upstream from a dam. For example, the
analysis and interpretation of stereoscopic color infrared
aerial photographs can be used to find and map specific
areas of concern where a high probability of NFS
pollution exists from septic tank systems, animal wastes,
soil erosion, and other similar types of NFS pollution
(TVA, 1988). Other remote sensing techniques, such as
analysis of satellite imagery, can be used to map areas of
concern within a watershed. Historically, TVA has used
analysis of aerial photography images to survey about
25 percent of the Tennessee Valley to identify sources of
nonpoint pollution in a period of less than 5 years at a cost
of a few cents per acre (TVA, 1988). Modern geographic
information systems (GIS) enable watershed planners and modelers to rapidly assess large
watersheds in a cost-effective manner.
The development of Total Maximum Daily Loads (TMDLs) in watersheds with impaired
waterbodies is a way to identify all sources of pollution. TMDLs are planning documents that
provide load allocations, for both point and nonpoint sources, and identify potential contributions
of pollutants to an impaired waterbody. TMDLs often include the involvement of stakeholders
throughout the watershed, in not only the development, but also with implementation of specific
activities within the watershed. TMDL documents can provide a plan for addressing pollution
sources throughout a watershed.
Different practices can be used to control NFS pollution once sources have been identified.
These practices may include the following:
Soil Erosion Control
Soil erosion has been determined to be the major source of suspended solids, nutrients, organic
wastes, pesticides, and sediment that combined form the most problematic form of NFS pollution
(TVA, 1988). Soil erosion and runoff controls have been addressed throughout earlier
management measures in this document.
Mine Reclamation
Abandoned mines may have the potential to contribute significant sediment, metals, acidified
water, and other pollutants to reservoirs (TVA, 1988). Old mines need to be located and
reclaimed to reduce NFS pollutants emanating from them. Revegetation is a cost-effective
method of reclaiming denuded strip-mined lands, and agencies such as the Natural Resource
Conservation Service (NRCS) can provide technical insight for revegetation practices.
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Chapter 7: Practices for Implementing Management Measures
Animal Waste Control
A major contributor to reservoir pollution in some watersheds is waste from animal confinement
facilities. TVA (1988) estimated that in the Tennessee Valley, farms produced about six times
the organic wastes of the population of the valley. EPA also has available the National
Management Measures to Control Nonpoint Source Pollution from Agriculture,5 which is a
technical guidance and reference document for use by state, local, and tribal managers in the
implementation of NFS pollution management programs. It contains information on a variety of
practices and management strategies for reducing pollution of surface and ground water from
agriculture (USEPA, 2003b).
Correcting Failing Septic Systems
The objective of this practice is to protect waterbodies from pollutants discharged by onsite
sewage disposal systems (OSDS). They should be sited, designed, and installed so that impacts
to waterbodies will be reduced to the extent practicable. Factors such as soil type, soil depth,
depth to water table, rate of sea level rise, and topography should be considered. The installation
of OSDS should be prevented in areas where soil absorption systems will not provide adequate
treatment of effluents containing solids, phosphorus, pathogens, nitrogen, and nonconventional
pollution prior to entry into surface waters and ground water. Setbacks, separation distances, and
maintenance requirements should be established.
Failing septic tank or OSDS are another source of NFS pollution in reservoirs. TVA has found
septic tank failures to be a problem in some of its reservoirs and has identified them through an
aerial survey (TVA, 1988). Additional guidance on OSDS is available from EPA's Onsite
Wastewater Treatment Systems Manual (EPA 625-R-00-008), which is available through EPA's
National Service Center for Environmental Publications.6
Land Use Planning
Land use plans that establish guidelines for permissible uses of land within a watershed serve as
a guide for reservoir management programs addressing NFS pollution (TVA, 1988). Watershed
land use plans identify suitable uses for land surrounding a reservoir, establish sites for economic
development and natural resource management activities, and facilitate improved land
management (TVA, 1988). Land use plans must be flexible documents that account for the needs
of the landowners, state and local land use goals, the characteristics of the land and its ability to
support various uses, and the control of NFS pollution (TVA, 1988).
Comprehensive planning is an effective nonstructural tool to control NFS pollution. Where
possible, growth should be directed toward areas where it can be sustained with minimal impact
on the environment (Meeks, 1990). Poorly planned growth and development have the potential
to degrade and destroy natural drainage systems and surface waters (Mantell et al., 1990). Proper
planning and zoning decisions allow water quality managers to direct development and land
disturbance away from areas that drain to sensitive waters. Land use designations and zoning
laws can also be used to protect environmentally sensitive areas such as riparian corridors and
wetlands.
5 http://www.epa.gov/owow/nps/pubs.html
6 http://www.epa.gov/ncepihom
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Chapter 7: Practices for Implementing Management Measures
Identify and Preserve Critical Areas
Protection of sensitive areas and areas that provide water
quality benefits (e.g., natural wetlands and riparian areas)
is integral to maintaining or minimizing the impacts of
development on receiving waters and associated habitat.
Without a comprehensive planning approach that includes
the use of riparian buffers, open space, bioretention, and
structural controls to maintain the predevelopment
hydrologic characteristics of the site, significant water
quality and habitat impacts are likely. The experience of
various communities has shown that the use of structural
controls in the absence of adequate local land use planning
and zoning often does not adequately protect water quality
and might even cause detrimental effects, such as
increased temperature.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
0 Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
An initial step for incorporating targeted land conservation
into a runoff management program is to identify critical conservation areas on a watershed map
and superimpose this information on a tax map. Owners of potential conservation lands could
include a mix of individuals, corporations or other business entities, homeowner associations,
government agencies, and land trusts.
Land conservation includes more than simply preserving land in its current state. It also means
that an individual or organization should take responsibility for restoration of areas of the
property that are contributing to runoff problems or have been adversely affected by runoff.
Stewardship activities for land conservation might include:
• Resource monitoring
• General maintenance
• Control of exotic species
• Installation of structural runoff management practices and maintenance
There are several options for landowners who would like to retain ownership of the parcel but
relinquish stewardship and conservation management to another organization. These
nonexclusive management options, discussed below, include establishing conservation
easements, leases, deed restrictions, covenants, or transfer of development rights (TDRs).
Conservation Easements
A conservation easement is a legal agreement that transfers specific rights concerning the use of
land by sale or donation to a government agency (municipal, county, or state), a qualified
nonprofit organization (e.g., land trust or conservancy), or other legal entity without transferring
title of the land (Cwikiel, 1996).
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Chapter 7: Practices for Implementing Management Measures
Leases
Even though government agencies, land trusts, and other nonprofit organizations would prefer
that conservation lands be acquired by donation or that conservation easements be placed on the
property, some lands hold so much value as conservation areas that leasing is worth the expense
and effort. Leasing a property allows the agency, trust, or organization to actively manage the
land for conservation.
Deed Restrictions
Restrictions can be included in deeds for the purpose of constraining use of the land. In theory,
deed restrictions are designed to perform functions similar to those of conservation easements. In
practice, however, deed restrictions have proven to be much weaker substitutes because unlike
conservation easements, deed restrictions do not necessarily designate or convey oversight
responsibilities to a particular agency or organization to enforce protection and maintenance
provisions. Also, deed restrictions can be relatively easy to modify or vacate through litigation.
Modifying or nullifying an easement is difficult, especially if tax benefits have already been
realized. For these reasons, conservation easements are generally preferred over deed
restrictions.
Covenants
A covenant is similar to a deed restriction in that it restricts activities on a property, but it is in
the form of a contract between the landowner and another party. The term mutual covenants is
used to describe a situation where one or more nearby or adjacent landowners are contracted and
covered by the same restrictions.
Transfer of Development Rights (TDRs)
The concept of TDRs as a watershed protection tool is based on the premise that ownership of
land includes a "bundle" of property rights. One of these rights is the right to develop the
property to its "highest and best use." Although this right can be restricted by zoning building
codes, environmental constraints, and other types of restrictions, the basic right to develop
remains. A TDR system creates an opportunity for property owners to transfer development
potential or density at one property, called a sending area to another property, called a receiving
area. In the context of watershed planning objectives, TDR programs can be an effective way to
transfer development potential from sensitive subwatersheds to subwatersheds that can better
deal with increased imperviousness.
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Chapter 7: Practices for Implementing Management Measures
Joint Planting
Joint planting (or vegetated riprap) involves tamping live
cuttings of rootable plant material into soil between the
joints or open spaces in rocks that have previously been
placed on a slope (Figure 7.19). Alternatively, the cuttings
can be tamped into place at the same time that rock is
being placed on the slope face. Joint planting is useful
where rock riprap is required or already in place. It is
successful 30 to 50 percent of the time, with first year
irrigation improving survival rates. Live cuttings must have
side branches removed and bark intact. They should range
from 0.5 to 1.5 inches in diameter and be long enough to
extend well into the soil, reaching into the dry season water
level. Installation guidelines are available from the USDA-
FS Soil Bioengineering Guide (USDA-FS, 2002) and the
USDANRCS Engineering Field Handbook, Chapter 18
(USDA-NRCS, 1992).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Additional Resources
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda. gov/techmcal/stream_restoration/PDFFILES/APPENDIX.pdf.
> ISU. 2006. How to Control Streambank Erosion: Joint Planting. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/ioint planting.pdf.
JOINT PLANTING
Note: Rooted, leafed condition of plant
material is not representative of the
time of installation
OHW, or Bankfufl
Baseflo!
Existing vegetation, plantings, or_
60\\ bioengineering techniques
Live Stakes
Existing
Grade
Streambed
Existing riprap, or place riprap
to protect toe of bank
Figure 7.19 Joint Planting (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Labyrinth Weir
Labyrinth weirs have extended crest length and are
usually W-shaped. These weirs spread the flow out to
prevent dangerous undertows in the plunge pool. A
labyrinth weir at South Holston Dam (Tennessee) was
constructed for the dual purpose of providing minimum
flows and improving DO in reservoir releases. The weir
aerates to up to 60 percent of the oxygen deficit. For
instance, projected performance at the end of the summer
is an increase in the DO from 3 mg/L to 7 mg/L (or an
increase of 4 mg/L) (Hauser, 1992). Actual increases in
the DO will depend on the temperature and the level of
DO in the incoming water.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Levees, Setback Levees, and Floodwalls
Many valuable techniques can be used, when applied
correctly, to protect, operate, and maintain levees
(Hynson et al., 1985). Evaluation of site-specific
conditions and the use of best professional judgment are
the best methods for selecting the proper levee protection
and operation and maintenance plan. According to
Hynson and others (1985), maintenance activities
generally consist of vegetation management, burrowing
animal control, upkeep of recreational areas, and levee
repairs.
Care must be taken during construction to prevent
disturbing the natural channel vegetation, cross section, or
bottom slope. No immediate instream effects from
sedimentation are usually caused by implementing this
type of modification. The potential for long-term channel
adjustments can be evaluated using methods outlined in Channel Stability Assessment for Flood
Control Projects (USAGE, 1994).
Methods to control vegetation include mowing, grazing, burning, and using chemicals. Selection
of a vegetation control method should consider the existing and surrounding vegetation, desired
instream and riparian habitat types and values, timing of controls to avoid critical periods,
selection of livestock grazing periods, and timing of prescribed burns to be consistent with
historical fire patterns. Additionally, a balance between the vegetation management practices for
instream and riparian habitat and engineering considerations should be maintained to avoid
structural compromise. Animal control methods are most effective when used as a part of an
integrated pest management program and might include instream and riparian habitat
manipulation or biological controls. Recreational area management includes upkeep of planted
areas, disposal of solid waste, and repairing of facilities (Hynson et al., 1985).
The prevention of floods by dams and levees can eliminate or diminish essential ecological
functions. Dams, levees and channel training structures have dramatically altered or eliminated
the frequency, duration, magnitude, and timing of periodic high flows. These projects
significantly reduce the likelihood of floodplain inundation, block the transfer of organic matter
and nutrients between river and floodplain, block plant succession, eliminate fish access to
spawning areas, and rob rivers of the erosive power to restore and create a diversity of habitats
(Environmental Defense, 2002). Levees have had several impacts on the Snake River in
Wyoming. Anthony (1998) found habitat losses, including changes in vegetation (including
losses of cottonwood and riparian habitats from 1956) and changes in channel and floodplain
complexity from a braided to a single channel pattern.
Siting of levees and floodwalls should be addressed prior to design and implementation of these
types of projects. Proper siting of such structures can avoid several types of problems. First,
construction activities should not disturb the physical integrity of adjacent riparian areas and/or
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Chapter 7: Practices for Implementing Management Measures
wetlands. Second, by setting back the structures (offsetting them from the streambank), the
relationship between the channel and adjacent riparian areas can be preserved. Proper siting and
alignment of proposed structures can be established based on hydraulic calculations, historical
flood data, and geotechnical analysis of riverbank stability.
Additional Resource
> LSU AgCenter. 1999. Floodwalls. Louisiana State University Agricultural Center, Louisiana
Cooperative Extension Service.
http://www.louisianafloods.org/NR/rdonlvres/7A01F7C8-703B-47Dl-BCCD-63CDOA57721F/
2995/pub2745Floodwall6.pdf.
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Chapter 7: Practices for Implementing Management Measures
Live Cribwalls
A live cribwall is used to rebuild a bank in a nearly
vertical setting. It consists of a hollow, box-like
interlocking arrangement of untreated log or timber
members (Figure 7.20). The structure is filled with
suitable backfill material and layers of live branch
cuttings, which root inside the crib structure and extend
into the slope. Logs or untreated timbers should range
from 4 to 6 inches in diameter. Lengths will vary with the
size of the crib structure. Fill rock should be 6 inches in
diameter. Live branch cuttings should be 0.5 to 2.5 inches
in diameter and long enough to reach the back of the
wooden crib structure. Once the live cuttings root and
become established, the subsequent vegetation gradually
takes over the structural functions of the wood members.
Live cribwalls are appropriate where space is limited and
at the base of a slope where a low wall may be required to
stabilize the toe of the slope and to reduce its steepness. They are also appropriate above and
below the water level where stable streambeds exist. They are not designed for or intended to
resist large, lateral earth stress. Installation guidelines are available from the USDA-FS Soil
Bioengineering Guide (USDA-FS, 2002) and the USDA NRCS Engineering Field Handbook,
Chapter 18 (USDA-NRCS, 1992).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
LIVE CRIBWALL
Existing
Bioengineering
Techniques-
Live Branch Cuttings
Geotextile
Fabric (Optional;
Rock Fill
Figure 7.20 Live Cribwall (USDA-FS, 2002)
Additional Resources
> FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
^ ISU. 2006. How to Control StreambankErosion: Live Cribwall. Iowa State University.
http ://www. ctre. iastate. edu/erosion/manuals/streambank/live crib wall .pdf.
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Live Cribwall. Created for United States Department of
Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/livecribwall.pdf.
> Ohio DNR. No date. Ohio Stream Management Guide: Live Cribwalls. Ohio Department of
Natural Resources, http://www.ohiodnr.com/water/pubs/fs st/stfs 17.htm.
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Chapter 7: Practices for Implementing Management Measures
Live Fascines
Live fascines are long bundles of branch cuttings bound
together in a cylindrical structure (Figure 7.21). They are
suited to steep, rocky slopes, where digging is difficult
(USDA-NRCS, 1992). When cut from appropriate species
(e.g., young willows or shrub dogwoods) that root easily
and have long straight branches, and when properly
installed, they immediately begin to stabilize slopes. The
cuttings (0.5 to 1.5 inches in diameter) form live fascine
bundles that vary in length from 5 to 10 feet or longer,
depending on site conditions and handling limitations.
Completed bundles should be 6 to 8 inches in diameter.
The goal is for natural recruitment to follow once slopes
are secured. Live fascines should be placed in shallow
contour trenches on dry slopes and at an angle on wet
slopes to reduce erosion and shallow face sliding. Live
fascines should be applied above ordinary high-water mark
or bankfull level except on very small drainage area sites. In arid climates, they should be used
between the high and low water marks on the bank. This system, installed by a trained crew,
does not cause much site disturbance.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Installation guidelines are available from the USDA-FS Soil Bioengineering Guide (USDA-FS,
2002) and the USDA NRCS Engineering Field Handbook, Chapter 18 (USDA-NRCS, 1992).
Under their Ecosystem Management and Restoration Research Program (EMRRP), the U.S.
Army Corps of Engineers presents research on live fascines in a technical note (Live and Inert
Fascine Streambank Erosion Control)1
Additional Resources
> Massachusetts DEP. 2006. Massachusetts Nonpoint Source Pollution Management Manual: Live
Fascines. Massachusetts Department of Environmental Protection, Boston, MA.
http://projects.geosvntec.corn/NPSManual/Fact%20Sheets/Live%20Fascmes.pdf.
^ Greene County Soil & Water Conservation District. No date. Construction Specification VS-01:
Live Fascines, http: //www. gcswcd. com/stream/library/pdfdocs/vs-01 .pdf.
> ISU. 2006. How to Control Streambank Erosion: Live Fascine. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/live fascine.pdf.
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Live Fascine. Created for United States Department of
Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/livefacme.pdf.
7 http://el.erdc.usace.army.mil/elpubs/pdf/sr31 .pdf
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Ohio DNR. No date. Ohio Stream Management Guide: Live Fascines. Ohio Department of
Natural Resources, http://www.ohiodnr.com/water/pubs/fs st/stfs 14.pdf.
LIVE FASCINE
Prepared Trench
Moist Soil Backfill
Live Stake:
2-3' spacing
between live stakes
Dead Stout
Stake: 2-5'
spacing along
bundle
OHW,
or Bankful
Seeding Between Trenches
(Optional)
Geotextile Fabric (optional)
Bundle of Live
Branches:
&-£>" diameter,
stagger
throughout
bundle
Note: OHW (Ordinary High Water) is the mark along a streambank where the waters are common and usual. This
mark is generally recognized by the difference in the character of the vegetation above and below the mark or the
absence of vegetation below the mark (USDA-FS, 2002).
Figure 7.21 Live Fascine (USDA-FS, 2002)
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Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Live Staking
Live staking (Figure 7.22) is appropriate for relatively
uncomplicated site conditions when construction time is
limited. It can also be used to stabilize intervening areas
between other soil bioengineering techniques (USDA-
NRCS, 1992). Live staking involves the insertion and
tamping of live, rootable vegetative cuttings into the
ground. If correctly prepared and placed, the live stake
will root and grow. A system of stakes creates a living
root mat that stabilizes the soil by reinforcing and binding
soil particles together and by extracting excess soil
moisture. Stakes are generally 1 to 2 inches in diameter
and 2 to 3 feet long. Specific site requirements and
available cutting source will determine size. Vegetation
selected should be able to withstand the degree of
anticipated inundation, provide year round protection,
have the capacity to become well established under
sometimes adverse soil conditions, and have root, stem, and branch systems capable of resisting
erosive flows. Most willow species are ideal for live staking because they root rapidly and begin
to dry out a slope soon after installation. Sycamore and cottonwood are also species commonly
used for live staking. This is an appropriate technique for repair of small earth slips and slumps
that are frequently wet. Installation guidelines are available from the USDA-FS Soil
Bioengineering Guide (USDA-FS, 2002) and the USDA NRCS Engineering Field Handbook,
Chapter 18 (USDA-NRCS, 1992).
Additional Resources
> ISU. 2006. How to Control StreambankErosion: Live Stakes. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/live_stakes.pdf.
> Myers, R.D. 1993. Slope Stabilization and Erosion Control Using Vegetation: A Manual of
Practice for Coastal Property Owners. Live Staking. Shorelands and Coastal Zone Management
Program, Washington Department of Ecology. Olympia. Publication 93-30.
http://www.ecv.wa.gov/programs/sea/pubs/93-30/livestaking.html.
^ Walter, J., D. Hughes, andNJ. Moore. 2005. Streambank Revegetation and Protection: A Guide
for Alaska. Revegetation Techniques: Live Staking. Revised Edition. Alaska Department of Fish
and Game, Division of Sport Fish.
http ://www. sf. adfg. state, ak. us/S ARR/restoration/techmques/livestake. cfm.
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Chapter 7: Practices for Implementing Management Measures
LIVE STAKING
Cross section
Not to scale
2 to 3 feet
Slope surface
Note:
Rooted/leafed condition of the living
plant material is not representative of
the time of installation.
2 to 3 feet
(triangular spacing)
Live cutting
1/2 to 1 1/2 inches in diameter
Figure 7.22 Live Staking (USDA-NRCS, 1992)
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Locate Potential Land Disturbing Activities
Away from Critical Areas
Material stockpiles, borrow areas, access roads, and other
land-disturbing activities can often be located away from
critical areas such as steep slopes, highly erodible soils,
and areas that drain directly into sensitive waterbodies.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Marsh Creation and Restoration
Marsh creation and restoration is a useful vegetative
technique that can address problems with erosion of
shorelines. Marsh plants perform two functions in
controlling shore erosion (Knutson, 1988). First, their
exposed stems form a flexible mass that dissipates wave
energy. As wave energy is diminished, the offshore
transport and longshore transport of sediment are reduced.
Ideally, dense stands of marsh vegetation can create a
depositional environment, causing accretion of sediments
along the intertidal zone rather than continued shore
erosion. Second, marsh plants form a dense mat of roots,
which can add stability to the shoreline sediments. The
basic approach for marsh creation is to plant a shoreline
area in the vicinity of the tide line with appropriate marsh
grass species. Suitable fill material may be placed in the
intertidal zone to create a wetlands planting terrace of
sufficient width (at least 18 to 25 feet) if such a terrace does not already exist at the project site.
For shoreline sites that are highly sheltered from the effects of wind, waves, or boat wakes, the
fill material is usually stabilized with small structures, similar to groins, which extend out into
the water from the land. For shorelines with higher levels of wave energy, the newly planted
marsh can be protected with an offshore installation of stone that is built either in a continuous
configuration or in a series of breakwaters.
Additional Resource
^ Maryland Department of the Environment. 2006. Shore Erosion Control Guidelines: Marsh
Creation. http://www.mde.state.md.us/assets/document/wetlandswaterways/Shoreerosion.pdf.
Channelization
D Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
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Modifying Operational Procedures
A useful tool for evaluating the effects of operational
procedures on the quality of tailwaters is computer
modeling. For instance, computer models can describe the
vertical withdrawal zone that would be expected under
different scenarios of turbine operation (Smith et al.,
1987). Zimmerman and Dortch (1989) modeled release
operations for a series of dams on a Georgia river and
found that procedures that were maintaining cool
temperatures in summer were causing undesirable
decreases in DO and increases in dissolved iron in
autumn. The suggested solution was a seasonal release
plan that is flexible, depending on variations in the in-
pool water quality and predicted local weather conditions.
Care should be taken with this sort of approach to
accommodate the needs of both the fishery resource and
reservoir recreationalists, particularly in late summer.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Modeling has also been undertaken for a variety of TV A and USAGE facilities to evaluate the
downstream impacts on DO and temperature that would result from changes in several
operational procedures, including (Hauser et al., 1990a; Hauser et al., 1990b; Higgins and Kim,
1982;Nestleretal., 1986):
• Maintenance of minimum flows
• Timing and duration of shutoff periods
• Seasonal adjustments to the pool levels
• Timing and variation of the rate of drawdown
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Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Mulching
Newly established vegetation does not have as extensive a
root system as existing vegetation and therefore is more
prone to erosion, especially on steep slopes. Additional
stabilization should be considered during the early stages
of seeding. This extra stabilization can be accomplished
using mulches or mulch mats, which are applied to
disturbed soil surfaces and can protect the area while
vegetation becomes established.
Mulches and mulch mats include tacked straw, wood
chips, and jute netting and are often covered by blankets
or netting. Mulching alone should be used only for
temporary protection of the soil surface or when
permanent seeding is not feasible. The useful life of
mulch varies with the material used and the amount of
precipitation, but, generally, is approximately 2 to 6
months. Mulching and/or sodding may be necessary as slopes become moderate to steep, as soils
become more erosive, and as areas become more sensitive. During the times of the year when
vegetation cannot be established, mulch can be applied to moderate slopes and soils that are not
highly erodible. On steep slopes or highly erodible soils, mulching may need to be reapplied if
washed away.
Additional Resources
^ Barr Engineering Company. 2001. Minnesota Urban Small Sites BMP Manual: Stormwater Best
Management Practices for Cold Climates. Soil Erosion Control: Mulches, Blankets and Mats.
Prepared for the Metropolitan Council by Barr Engineering Company, St. Paul, MN.
http://www.metrocouncil.org/EnvironmentAVatershed/BMP/CH3 RPPSoilMulch.pdf.
> CASQA. 2004. California Stormwater BMP Construction Handbook. Hydraulic Mulch.
California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/EC-3.pdf.
> ISU. 2006. Iowa Construction Site Erosion Control Manual: Mulching. Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/2.3 mulching.pdf.
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Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Noneroding Roadways
General Road Construction Considerations
Road design and construction activities that are tailored to
topography and soils and take into consideration the
overall drainage pattern in the watershed where the road is
being constructed can prevent road-related water quality
problems. Lack of adequate consideration of watershed and
site characteristics, road system design, and construction
techniques appropriate to the site can result in mass soil
movements, extensive surface erosion, and severe
sedimentation in nearby waterbodies. The effect that a road
network has on stream networks largely depends on the
extent to which the networks are interconnected. Road
networks can be hydrologically connected to stream
networks where road surface runoff is delivered directly to
stream channels (at stream crossings or via ditches or
gullies that direct flow off the road into a stream) and where road cuts transform subsurface flow
into surface flow (in road ditches or on road surfaces that deliver sediment and water to streams
much more quickly than without a road present). The combined effects of these drainage
network connections are increased sedimentation and peak flows that are higher and arrive more
quickly after storms. This can lead to increased instream erosion and stream channel changes,
especially in small watersheds (USEPA, 2005a).
Site characteristics should be considered during construction planning. On-site verification of
information from topographic maps, soil maps, and aerial photos can ensure that locations where
roads are to be cut into slopes or built on steep slopes or where skid trails, landings, and
equipment maintenance areas are to be located are appropriate to the use. If an on-site visit
indicates that construction changes can reduce the risk of erosion, the project manager can make
these changes prior to construction, and in some cases as the project progresses (USEPA, 2005a).
Road drainage features tailored to the site prevent water from pooling or collecting on road
surfaces. This prevents saturation of the road surface, which can lead to rutting, road slumping,
and channel washout. Many roads associated with channelization projects are temporary or
seasonal-use roads, and their construction should not involve the high level of disturbance
generated by construction of permanent, high-standard roads. However, these types of roads still
need to be constructed and maintained to prevent erosion and sedimentation (USEPA, 2005a).
Erosion control practices need to be applied while a road is being constructed, when soils are
most susceptible to erosion, to minimize soil loss to waterbodies. Since sedimentation from roads
often does not occur incrementally and continuously, but in pulses during large rainstorms, it is
important that road, drainage structure, and stream crossing design take into consideration a
sufficiently large design storm that has a good chance of occurring during the life of the project.
Such a storm might be the 10-year, 25-year, 50-year, or even 100-year, 12- to 24-hour return
period storm. Sedimentation cannot be completely prevented during or after road construction,
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Chapter 7: Practices for Implementing Management Measures
but the process is exacerbated if the road construction and design are inappropriate for the site
conditions or if the road drainage or stream crossing structures are insufficient (USEPA, 2005a).
When constructing a new road, it is useful to consider road surface shape and composition, slope
stabilization, and wetlands. A more detailed discussion of these topics is provided below. More
information about potential impacts to fish habitat and passage are provided in EPA's National
Management Measures to Control Nonpoint Source Pollution from Forestry.,8
Road Shape and Composition
The shape of a road is an important runoff control component. Road drainage and runoff control
are obtained by shaping the road surface to be insloping, outsloping, or crowned. Insloping roads
can be effective where soils are highly erodible and directing runoff directly to the fill slope
would be detrimental. Outsloped roads tend to dissipate runoff more than insloped roads, which
concentrate runoff at cross drain locations, and are useful where erosion of backfill or ditch soil
might be a problem. Crowned roads are suited to two lane roads and to steep single-lane roads
that have frequent cross drains or ditches and ditch relief culverts (USEPA, 2005a). These road
surface shapes are illustrated in Figure
7.23. Maintain one of these shapes to
ensure good drainage. Crowns, inslopes,
and outslopes will quickly lose
effectiveness if not maintained frequently,
due to ruts created by traffic when the road
surface is damp or wet (USEPA, 2005a).
Road surface composition can effectively
control erosion from road surfaces and
slopes. It is important to choose a surface
that is suitable to the topography, soils, and
intended use. Surface protection of the
roadbed and cut-and-fill slopes with a
suitable material can minimize soil losses
during storms, reduce frost heave erosion
production, restrain downslope movement
of soil slumps, and minimize erosion from
softened roadbeds (USEPA, 2005a).
Slope Stabilization
Road cuts and fills can be a large source of
sediment when constructing a rural road.
Figure 7.23 Types of Road Surface Shapes (USEPA, 2005a)
Stabilizing back slopes and fill slopes as they are constructed is important in minimizing erosion
from these areas. Combined with gravel or other surfacing, establishing grass or another form of
slope stabilization can significantly reduce soil loss from road construction. If constructing on an
unstable slope is necessary, consider consulting with an engineering geologist or geotechnical
1 Available online at http://www.epa.gov/owow/nps/forestrymgmt.
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Chapter 7: Practices for Implementing Management Measures
engineer for recommended construction methods and to develop plans for the road segment.
Unstable slopes that threaten water quality should be considered unsuitable for road building.
Planting grass on cut-and-fill slopes of new roads can effectively reduce erosion, and placing
forest floor litter or brush barriers on downslopes in combination with establishing grass is also
effective for reducing downslope sediment transport. Grass-covered fill is generally more
effective than mulched fill in reducing soil erosion from newly constructed roads because of the
roots that hold the soil in place, which are lacking with other cover. Because grass needs some
time to establish itself, a combination of straw mulch with netting to hold it in place can be used
to cover a seeded area and effectively reduce erosion while grass is growing. The mulch and
netting provide immediate erosion control and promote grass growth (USEPA, 2005a).
Wetland Road Considerations
Sedimentation is a concern when considering road construction through wetlands. It is better to
avoid putting a road through a wetland when an alternative route exists. If no alternative exists,
make sure to implement best management practices (BMPs) suggested by the state. Road
construction or maintenance for certain farming, forestry, or mining activities might be exempt
under Clean Water Act (CWA) section 404. However, to qualify for the exemption, the roads
must be constructed and maintained following application of specific BMPs designed to protect
the aquatic environment (USEPA, 2005a).
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Pesticide and Fertilizer Management
Chemicals used in dam management include pesticides
(insecticides, herbicides, and fungicides) and fertilizers.
Since pesticides can be toxic, they have to be mixed,
transported, loaded, and applied correctly and their
containers disposed properly to prevent potential nonpoint
source pollution. Since fertilizers can also be toxic or can
damage the ecosystem, it is important that they be handled
and applied properly, according to label instructions.
Even though a limited number of applications might be
made at a specific dam site, consider that throughout a
watershed many sites could receive applications of
fertilizers and pesticides, which can accumulate in soils
and in waterbodies. Application techniques also partly
determine the potential risk to the aquatic environment
from infrequent applications of pesticides and fertilizers.
These chemicals can directly enter surface waters through five
application, drift, mobilization in ephemeral streams, overland
application is the most important source of increased chemical
the most easily controlled.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
0 Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
major pathways—direct
flow, and leaching. Direct
concentrations and is also one of
Some more specific implementation practices for pesticide maintenance include:
• Apply pesticides during favorable atmospheric conditions. Do not apply pesticides when
wind conditions increase the likelihood of significant drift. It is also best to avoid
pesticide application when temperatures are high or relative humidity is low because
these conditions influence the rate of evaporation and enhance losses of volatile
pesticides.
• Ensure that pesticide users abide by the current pesticide label, which might specify
whether users be trained and certified in the proper use of the pesticide; allowable use
rates; safe handling, storage, and disposal requirements; and whether the pesticide may be
used under the provisions of an approved State Pesticide Management Plan.
• Locate mixing and loading areas, and clean all mixing and loading equipment thoroughly
after each use, where pesticide residues will not enter streams or other waterbodies.
• Dispose of pesticide wastes and containers according to state and federal laws.
• Consider the use of pesticides as only one part of an overall program to control pest
problems. Integrated Pest Management (IPM) strategies have been developed to control
pests without total reliance on chemical pesticides.
• Base selection of pesticide on site factors and pesticide characteristics. These factors
include vegetation height, target pest, adsorption (attachment) to soil organic matter,
persistence or half-life, toxicity, and type of formulation.
• Check all equipment carefully, particularly for leaking hoses and connections and
plugged or worn nozzles. Calibrate spray equipment periodically to achieve uniform
pesticide distribution and rate.
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Chapter 7: Practices for Implementing Management Measures
• Always use pesticides in accordance with label instructions, and adhere to all federal and
state policies and regulations governing pesticide use.
Specific implementation practices for fertilizer maintenance include:
• Apply slow-release fertilizers when possible. This practice reduces potential nutrient
leaching to ground water, and it increase the availability of nutrients for plant uptake.
• Apply fertilizer during favorable atmospheric conditions. Do not apply fertilizer when
wind conditions increase the likelihood of significant drift.
• Apply fertilizers during maximum plant uptake periods to minimize leaching.
• Base fertilizer type and application rate on soil and/or foliar analysis.
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Chapter 7: Practices for Implementing Management Measures
Phase Construction
Construction site phasing involves disturbing only small
portions of a site at a time to prevent erosion from dormant
parts (CWP, 1997 c). Grading activities and construction
are completed and soils are effectively stabilized on one
part of the site before grading and construction commence
at another. This is different from the more traditional
practice of construction site sequencing, in which
construction occurs at only one part of the site at a time but
site grading and other site-disturbing activities typically
occur all at once, leaving portions of the disturbed site
vulnerable to erosion. To be effective, construction site
phasing must be incorporated into the overall site plan
early. Elements to consider when phasing construction
activities include (CWP, 1997c):
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
• Managing runoff separately in each phase
• Determining whether water and sewer connections and extensions can be accommodated
• Determining the fate of already completed downhill phases
• Providing separate construction and residential accesses to prevent conflicts between
residents living in completed stages of the site and construction equipment working on
later stages
A comparison of sediment loss from a typical development and from a comparable phased
project showed a 42 percent reduction in sediment export in the phased project (CWP, 1997c).
Phasing can also provide protection from complete enforcement and shutdown of the entire
project. If a contractor is in noncompliance in one phase or zone of a site, that will be the only
zone affected by enforcement. This approach can help to minimize liability exposure and protect
the contractor financially (Deering, 2000b).
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Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Physical Barriers
Physical barriers are diversion systems that lead or force
fish to bypasses that transport them above or below the
dam (FAO, 2001). Physical diversion structures deployed
at dams include angled screens, drum screens, inclined
plane screens, louvers, and traveling screens. The success
and effectiveness of physical barriers has been found to be
specific to individual hydropower facilities (Mattice,
1990).
Angled screens are used to guide fish to a bypass by
guiding them through the channel at some angle to the
flow. Coarse-mesh angled screens have been shown to be
highly effective with numerous warm- and cold-water
species at adult life stages. Fine-mesh angled screens have
been shown in laboratory studies to be highly effective in
diverting larval and juvenile fish to a bypass with resultant
high survival. Performance of angled screens can vary by species, stream velocity, fish length,
screen mesh size, screen type, and temperature (Stone and Webster, 1986). Clogging from debris
and fouling organisms is a maintenance problem associated with angled screens.
Angled rotary drum screens oriented perpendicular to the flow direction have been used
extensively to lead fish to a bypass. Angled rotary drum screens tend not to experience the major
operational and maintenance clogging problems of stationary screens, such as angled vertical
screens. Maintenance of angled rotary drum screens typically consists of routine inspection,
cleaning, lubrication, and periodic replacement of the screen mesh (Stone and Webster, 1986).
An inclined plane screen is used to divert fish upward in the water column into a bypass. Once
concentrated, the fish are transported to a release point below the dam. An inclined plane
pressure screen at the T.W. Sullivan Hydroelectric Project (Willamette Falls, Oregon) is located
in the penstock of one unit. The design is effective in diverting fish, with a high survival rate.
However, this device has been linked to injuries in some species of migrating fish, and it has not
been accepted for routine use (Stone and Webster, 1986).
Louvers consist of an array of evenly spaced, vertical slats aligned across a channel at an angle
leading to a bypass. The turbulence they create is sensed and avoided by the fish (Stone and
Webster, 1986). Louver systems rely on a fish's instincts to use senses other than sight to move
around obstacles. Once the louver is sensed, the fish tend to reverse their head first downstream
orientation (to head upstream, tail to the louver) and move laterally along it until they reach the
bypass (OTA, 1995).
Submerged traveling screens are used to divert downstream migrating fish out of turbine intakes
to adjoining gatewell structures, where the fish are concentrated for release downstream. This
device has been tested extensively at hydropower facilities on the Snake and Columbia Rivers.
Because of their complexity, submerged traveling screens must be continually maintained. The
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Chapter 7: Practices for Implementing Management Measures
screens must be serviced seasonally, depending on the debris load, and trash racks and bypass
orifices must be kept free of debris (Stone and Webster, 1986).
Physical barrier fish diversion systems have been found to work best when specifically designed
to the structure and fish being passed. Small differences in design, such as the spacing or depth
of the louvers, can mean the difference in success and failure. A successful louver system has
been installed at the Holyoke Hydroelectric Power Station, on the Connecticut River. This partial
depth louver system was installed in the intake channel at the power plant and successfully
passed 86 percent of the juvenile clupeids and 97 percent of the Atlantic salmon (Salmo solar)
smolts (Marmulla, 2001). Another partial depth louver system on the same river has experienced
less successful results. The system installed at the Vernon Dam on the Connecticut River is
successfully passing about 50 percent of the Atlantic salmon smolts (OTA, 1995).
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Chapter 7: Practices for Implementing Management Measures
Pollutant Runoff Control
Store, cover, and isolate construction materials, refuse,
garbage, sewage, debris, oil and other petroleum products,
mineral salts, industrial chemicals, and topsoil to prevent
runoff of pollutants and contamination of ground water.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
0 Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Preserve Onsite Vegetation
Preserving onsite vegetation retains soil and limits runoff
of water, sediment, and pollutants. The destruction of
existing onsite vegetation can be minimized by initially
surveying the site to plan access routes, locations of
equipment storage areas, and the location and alignment
of the dam. Construction workers can be encouraged to
limit activities to designated areas only. Reducing the
disturbance of vegetation also reduces the need for
revegetation after construction is completed, including the
required fertilization, replanting, and grading that are
associated with revegetation. Additionally, as much
natural vegetation as possible should be left next to the
waterbody where construction is occurring. This
vegetation provides a buffer to reduce the NFS pollution
effects of runoff originating from areas associated with
the construction activities.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Additional Resource
> CASQA. 2004. California Stormwater BMP Construction Handbook. Preservation of Existing
Vegetation. California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/EC-2.pdf.
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Chapter 7: Practices for Implementing Management Measures
Reregulation Weir
Reregulation weirs have been constructed from stone,
wood, and aggregate. In addition to increasing the levels
of DO in the tailwaters, reregulation weirs result in a
more constant rate of flow farther downstream during
periods when turbines are not in operation. A reregulation
weir constructed downstream of the Canyon Dam
(Guadalupe River, Texas) increased DO levels in waters
leaving the turbine from 3.3 mg/L to 6.7 mg/L (EPRI,
1990).
The USAGE Waterways Experiment Station (Wilhelms,
1988) has compared the effectiveness with which various
hydraulic structures accomplished the reaeration of
reservoir releases. The study concluded that, whenever
operationally feasible, more discharge should be passed
over weirs to improve DO concentrations in releases.
Results indicated that overflow weirs aerate releases more effectively than low-sill spillways
(Wilhelms, 1988).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Reservoir Aeration
Some techniques for reservoir aeration include:
• Air injection systems
• Diffused air systems
• Oxygen injection systems
• U-tube design
Air injection systems mix water from different strata in
the impoundment by using air or pure oxygen injected
into a pumping system. Air injection systems are
categorized as partial air lift systems and full air lift
systems. In the partial air lift system, compressed air is
injected at the bottom of the unit; then the air and water
are separated at depth and the air is vented to the surface.
In the full air lift system, compressed air is injected at the
bottom of the unit (as in the partial air lift system), but the air
The full air lift design has a higher efficiency than the partial-;
elevate dissolved nitrogen levels (Thornton et al., 1990).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
0 Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
water mixture rises to the surface.
air lift and has a lesser tendency to
Diffused air systems provide effective transfer of oxygen to water by forcing compressed air
through small pores in diffuser systems to form bubbles. One diffuser system test in the
Delaware River near Philadelphia, Pennsylvania in 1969-1970 demonstrated the efficiency of
this practice. Coarse-bubble diffusers were deployed at depths ranging from 13 to 38 feet.
Depending on the depth of deployment, the oxygen transfer efficiency varied from 1 to 12
percent. When compared with other systems discussed below, this efficiency rate is rather low.
But the results of this test determined that river aeration was more economical than advanced
wastewater treatment as a strategy for improving the levels of DO in the river (EPRI, 1990).
Another type of oxygen injection system, which pumps gaseous oxygen into the hypolimnion
through diffusers, has effectively improved DO levels in the reservoir behind the Richard B.
Russell Dam (Savannah River, on the Georgia-South Carolina border). The system is operated 1
mile upstream of the dam, with occasional supplemental injection of oxygen at the dam face
when DO levels are especially low. The system has successfully maintained DO levels above 6
mg/L in the releases, with an average oxygen transfer efficiency of 75 percent (EPRI, 1990;
Gallagher and Mauldin, 1987).
The diffused air system has been found to be a cost-effective method to raise low DO levels
within a reservoir (Henderson and Shields, 1984). However, the costs of air diffuser operation
may be high for deep reservoirs because of hydraulic pressures that must be overcome.
Destratification that results from deployment of an air diffuser system may also mix nutrient-rich
waters located deep in the impoundment into layers located closer to the surface, increasing the
potential for stimulation of algal populations. Barbiero et al. (1996), in a study on the effects of
artificial circulation on a small northeastern impoundment, found that artificial circulation
ultimately had no effect on the magnitude of summer phytoplankton populations. However, the
authors note that intermittent mixing events tend to promote increased transport of phosphorus
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Chapter 7: Practices for Implementing Management Measures
into the epilimnion. While this had no effect on phytoplankton populations in the studied lake, it
demonstrates the potential of artificial circulation to impact water quality and the need for careful
evaluation of potential impacts.
Oxygen injection systems use pure oxygen to increase levels of dissolved oxygen in reservoirs.
One type of design, termed side stream pumping, carries water from the impoundment onto the
shore and through a piping system into which pure oxygen is injected. After passing through this
system, the water is returned to the impoundment (EPRI, 1990).
The U-tube design, in which water from deep in the impoundment is pumped to the surface
layer, provides a means to aerate reservoir waters. Oxygen transfer is increased as a mixture of
water and oxygen gas is subjected to greater hydrostatic pressure. Water moves down the U-tube
and pressure increases as a function of depth, dissolving the oxygen gas into the water. The
oxygenated water then travels back up through the system and is released to the waterway (Jones
and Stokes, 2004). The inducement of artificial circulation through aeration of the impoundment
may also provide the opportunity for a "two-story" fishery, reduce internal phosphorus loading,
and eliminate problems with iron and manganese in drinking water (Thornton et al., 1990).
If the principal objective is to improve DO levels only in the reservoir releases and not
throughout the entire impoundment, then aeration can be applied selectively to discrete layers of
water immediately surrounding the intakes or as water passes through release structures such as
hydroelectric turbines. Localized mixing is a practice to improve releases from thermally
stratified reservoirs by destratifying the reservoir in the immediate vicinity of the outlet structure.
This practice differs from the practice of artificial destratification, where mixing is designed to
destratify all or most of the reservoir volume (Holland, 1984). Localized mixing is provided by
forcing a jet of high-quality surface water downward into the hypolimnion. Pumps used to create
the jet generally fall into two categories, axial flow propellers and direct drive mixers (Price,
1989). Axial flow pumps usually have a large-diameter propeller (6 to 15 feet) that produces a
high-discharge, low-velocity jet. Direct drive mixers have small propellers (1 to 2 feet) that
rotate at high speeds and produce a high-velocity jet. The axial flow pumps are suitable for
shallow reservoirs because they can force large quantities of water down to shallow depths. The
high-momentum jets produced by direct drive mixers are necessary to penetrate deeper reservoirs
(Price, 1989).
Additional Resource
> Thornton, K.W., B.L. Kimmel, and F.E. Payne. 1990. Reservoir Limnology: Ecological
Perspectives. John Wiley & Sons, Inc., New York.
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Chapter 7: Practices for Implementing Management Measures
Retaining Walls
Retaining walls are used in areas where soils are unstable,
where slopes are steeper than the angle of repose, and
where the horizontal distance is limited. They help
stabilize slopes and can decrease the steepness of a slope.
If the steepness of a slope is reduced, the runoff velocity
is decreased and, therefore, the erosion potential is
decreased.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
According to the Iowa Construction Site Erosion Control
Manual., a variety of materials can be used for
construction of retaining walls, including concrete
masonry, concrete cribbing, steel piling, gabions, precast
stone, rock riprap, reinforced earth, stone drywall, and
treated wood timbers. Costs vary by the material selected
for construction. When designing a retaining wall, the
following factors should be taken into account: drainage,
bearing value of the soil, wall thickness, stress, foundation design, and wall height.
Additional Resources
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Retaining Wall. Iowa State
University. http://www.ctre.iastate.edU/erosion/manuals/construction/3.13_retaining_wall.pdf.
> Leposky, R.E. 2004. Retaining Walls: What You See and What You Don't.
http://www.forester.net/ecm 0401 retainmg.html.
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Chapter 7: Practices for Implementing Management Measures
Return Walls
Whenever shorelines or streambanks are "hardened"
through the installation of bulkheads, seawalls, or
revetments, the design process must include consideration
that waves and currents can continue to dislodge the
substrate at both ends of the structure, resulting in very
concentrated erosion and rapid loss of fastland. This
process is called flanking. To prevent flanking, return walls
should be provided at either end of a vertical protective
structure and should extend landward for a horizontal
distance consistent with the local erosion rate and the
design life of the structure.
Additional Resource
> USAGE. 1985. Coastal Engineering Technical Note:
Determining Lengths of Return Walls. U.S. Army
Engineer Waterways Experiment Station.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
http://chl.erdc.usace.army.mil/librarv/publications/chem/pdf/cetn-iii-25.pdf.
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Revegetate
Revegetation of construction sites during and after
construction is the most effective way to permanently
control erosion (Hynson et al., 1985). To select the right
plants for your bioengineering project, note what native
plant communities grow in the area. Avoid planting
noxious or invasive grasses, such as reed canary grass or
ryegrass. Remove invasive plants such as yellow
starthistle, English ivy, deadly nightshade, field morning
glory, scotch broom, cheatgrass, and purple loosestrife.
Use more of the same native plants in the bioengineering
design, as these plants are most likely adapted to
conditions to the area.
Plants like willow, red osier dogwood, alder, ash, and
cottonwood can be well suited for bioengineering. They
establish easily, grow quickly, and have thick root
systems. Cuttings are available from native plant nurseries. They may also be collected next to
the project site, if the area is well vegetated (Oregon Association of Conservation Districts,
2004).
Ecological and vegetational areas vary throughout the country. Therefore, other plant materials
may be more suitable for a project. Contact local cooperative extension services for more plant
information.9
Additional Resources
^ Barr Engineering Company. 2001. Minnesota Urban Small Sites BMP Manual: Stormwater Best
Management Practices for Cold Climates. Soil Erosion Control: Vegetative Methods. Prepared
for the Metropolitan Council by Barr Engineering Company, St. Paul, MN.
http://www.metrocouncil.org/environmentAVatershed/BMP/CH3 RPPSoilVeget.pdf.
> Ohio DNR. No date. Ohio Stream Management Guide: Restoring Streambanks with Vegetation.
Ohio Department of Natural Resources. http://www.ohiodnr.com/water/pubs/fs_st/stfs07.htm.
' http://www.csrees.usda.gov/qlinks/partners/state partners.html
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Chapter 7: Practices for Implementing Management Measures
Revetment
A revetment (Figure 7.24) is a type of vertical protective
structure used for shoreline protection. One revetment
design contains several layers of randomly shaped and
randomly placed stones, protected with several layers of
selected armor units or quarry stone. The armor units in
the cover layer should be placed in an orderly manner to
obtain good wedging and interlocking between individual
stones. The cover layer may also be constructed of
specially shaped concrete units (USAGE, 1984).
Sometimes gabions (stone-filled wire baskets) or
interlocking blocks of precast concrete are used in the
construction of revetments. In addition to the surface
layer of armor stone, gabions, or rigid blocks, successful
revetment designs also include an underlying layer
composed of either geotextile filter fabric and gravel or a
crushed stone filter and bedding layer. This lower layer
functions to redistribute hydrostatic uplift pressure caused by wave action in the foundation
substrate. Precast cellular blocks, with openings to provide drainage and to allow vegetation to
grow through the blocks, can be used in the construction of revetments to stabilize banks.
Vegetation roots add additional strength to the bank. In situations where erosion can occur under
the blocks, fabric filters can be used to prevent the erosion. Technical assistance should be
obtained to properly match the filter and soil characteristics. Typically blocks are hand placed
when mechanical access to the bank is limited or costs need to be minimized. Cellular block
revetments have the additional benefit of being flexible to conform to minor changes in the bank
shape (USACE, 1983).
Additional Resource
> Ohio DNR. No date. Ohio Stream Management Guide: Riprap Revetments. Ohio Department of
Natural Resources, http://www.ohiodnr.com/water/pubs/fs st7stfsl6.pdf.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Quarrystone
Filter—Layer
Uniform—sized
armor stone or
graded riprap
Field Stone
"-Large, rounded
field stone
armor
— Filter
Concrete
Cost in place
concrete slab
on grade
Bags
filter
Sand or
croncrete fill in
frabric bags
Gabions
—Rock-filled
gabion baskets
Vegetation
Beoeri and upland
species above the
interttdol zone
Marsh species in
the intertidal zone
Concrete Armor
Units
Filter
Concrete Revetment
Blocks
~- Randomly- or
specially—placed
armor units
"- Underioyer such as trlbars,
dolosse, etc.
Concrete—Filled
Mattress
Concrete—filled
mattress
Concrete Slabs
Concrete
from demolition
work
Landing Mat
,
^ \-—Landing Mat
Figure 7.24 Revetment Alternatives (USAGE, 2003)
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Chapter 7: Practices for Implementing Management Measures
Riparian Improvements
Riparian improvements are another strategy that can be
used to restore or maintain aquatic and riparian habitat
around reservoir impoundments or along the waterways
downstream from dams. In fact, Johnson and LaBounty
(1988) found that riparian improvements were more
effective, in some cases, than flow augmentation for
protection of instream habitat. In the Salmon River (Idaho),
a variety of instream and riparian habitat improvements
have been recommended to improve the indigenous stocks
of Chinook salmon (Oncorhynchus tshawytscha). These
improvements include reducing sediment loading in the
watershed, improving riparian vegetation, eliminating
barriers to fish migration (see sections discussing this
practice below), and providing greater instream and
riparian habitat diversity (Andrews, 1988).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
0 Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Maintaining and improving riparian areas upstream of a dam may also be an important
consideration for reducing flow-related impacts to dams. Riparian areas along brooks and
smaller streams are sometimes altered in a manner that impairs their ability to detain and absorb
floodwater and stormwater (e.g., removal of forest cover or increased imperviousness). The
cumulative impact of the riparian changes results in the smaller streams discharging increased
volumes and velocities of water, which then result in more severe downstream flooding and
increased storm damage and/or maintenance to existing structures (such as dams). These
downstream impacts may occur even though main stem floodplains and riparian areas are
safeguarded and remain close to their natural condition (Cohen, 1997).
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Chapter 7: Practices for Implementing Management Measures
Riprap
Riprap is a layer of appropriately sized stones designed
to protect and stabilize areas subject to erosion, slopes
subject to seepage, or areas with poor soil structure.
Riprap extends from the toe of the slope to a height
needed for long term durability (Figure 7.25).
Riprap can be used where vegetation cannot be
established or in combination with vegetative approaches.
This method is suitable where stream flow velocity is
high or where there is a threat to life or property. This
method can be expensive, particularly if materials are not
locally available. This method should be combined with
soil bioengineering techniques, particularly revegetation
efforts, to achieve a comprehensive streambank
restoration design (FISRWG, 1998).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Additional Resources
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Riprap. Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/3.15 riprap.pdf.
> Tennessee Department of
Environment and
Conservation. 2002. Erosion
and Sediment Control
Handbook: Riprap.
Tennessee Department of
Environment and
Conservation, Nashville, TN.
http: //state, tn. us/environment/
wpc/sed ero controlhand
book/rr.pdf.
OVERTOPPING
., APRON
gf shoreline PS often
owr topped by
storm waves)
-nr^
3MOR LAV ER
(graded rock rip-rap)
GEOTEXTILE FABRIC
AND/OR
GRADED STONE
FILTER
Proper riprap placement (MHW=mean high water, MLW=mean
low water).
Figure 7.25 Riprap Diagram
(http://www.extension.umn.edu/distribution/naturalresources/
components/DD6946g.html')
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Chapter 7: Practices for Implementing Management Measures
Root Wad Revetments
Root wads armor a bank by keeping faster moving
currents away from the bank (Figures 7.26 and 7.27). They
are most useful for low energy streams that meander and
have out-of-bank flow conditions. Root wads should be
used in combination with other soil bioengineering
techniques to stabilize a bank and ensure plant
establishment on the upper portions of the streambank.
Stabilizing the bank will reduce streambank erosion, trap
sediment, and improve habitat diversity. There are a
number of ways to install root wads. The trunk can be
driven into the bank, laid in a deep trench, or installed as
part of a log and boulder revetment. Use tree wads that
have brushy top and durable wood, such as Douglas fir,
oak, hard maple, juniper, spruce, cedar, red pine, white
pine, larch, or beech. Ponderosa pine and aspen are too
inflexible, and alder decomposes rapidly.
With the added support of a log and boulder revetment, root wads can stabilize banks of high-
energy streams. Root wad span should be approximately 5 feet with numerous root protrusions.
The trunk should be at least 8 to 12 feet long. Boulders should be as large as possible, but at least
one and a half times the log's diameter. They should also have an irregular surface. Logs are to
be used as footers or revetments and should be over 16 inches in diameter.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
When logs and root wads
are well anchored, this
design will tolerate high
boundary shear stress.
However, local scour and
erosion is possible.
Varying with climate and
tree species used, the
decomposition of the logs
and rootwads will limit
the life span of this
design. If colonization of
streambank vegetation
does not take place,
replacement may be
required. The project site
must be accessible to
heavy equipment.
Locating materials may be
difficult in some locations
and this method can be expensive (FISRWG, 1998).
ROOT WAD. LOG, AND BOULDER REVETMENT WITH FOOTER: PLAN VIEW
(Not to scale)
•>
Figure 7.26 Root Wad, Log, and Boulder Revetment with Footer: Plan View
(USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Installation guidelines are available from the USDA-FS Soil Bioengineering Guide (USDA-FS,
2002). Under EMRRP, the USAGE has presented research on rootwad composites in a technical
note (Rootwad Composites for Streambank Erosion Control and Fish Habitat Enhancement).10
ROOTWAD, LOG, AND BOULDER REVETMENT WITH FOOTER: SECTION
(Not to scale)
Root wad: if possible,
partially embed root
fan into river bottom
- OHW,
or Bankfull
Log: 6'-12' Length
Diameter of Log
16 in. Minimum
Boulder: 11/2 times _
diameter of log
y Base Flow
Live Posts:
roots
should
extend to
dry season
water level
-Geotextile
Fabric
(Optional)
°O Q> O O o O
Dry Season Water Level
Figure 7.27 Rootwad, Log, and Boulder Revetment with Footer: Section (USDA-FS, 2002)
Additional Resources
> FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
> Harmon, W.A. and R. Smith. 2000. Using Root Wads and Rock Vanes for Streambank
Stabilization. River Course Fact Sheet Number 4. North Carolina Cooperative Extension Service.
http: //www. bae. ncsu. edu/pro grams/extension/wqg/sri/rv-crs-4. pdf.
^ Walter, J., D. Hughes, andNJ. Moore. 2005. Streambank Revegetation and Protection: A Guide
for Alaska. Revegetation Techniques: Root Wads. Revised Edition. Alaska Department of Fish
and Game, Division of Sport Fish.
http ://www. sf. adfg. state, ak. us/S ARR/restoration/techniques/rootwad. cfm.
10
http://el.erdc.usace.army.mil/elpubs/pdf/sr21 .pdf
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
0 Planning & regulatory
Rosgen's Stream Classification Method
Rosgen's stream channel stability method provides a
sequence of steps for the field practitioner to use in
reaching final conclusions and making recommendations
for management, stream design, or restoration. The field
practitioner uses field-measured variables to assess:
• Stream state or channel condition variables
• Vertical stability (degradation/aggradation)
• Lateral stability
• Channel patterns
• Stream profile and bed features
• Channel dimension factor
• Channel scour/deposition (with competence
calculations of field verified critical dimensionless
shear stress and change in bed and bar material size
distribution)
• Stability ratings adjusted by stream type
• Dimensionless ratio sediment rating curves by stream type and stability ratings
• Selection of position in stream type evolutionary scenario as quantified by morphological
variables by stream type to determine state and potential of stream reach.
The stability assessment is conducted on a reference reach and a departure analysis is performed
when compared to an unstable reach of the same stream type. Changes in the variables
controlling river channel form, primarily streamflow, sediment regime, riparian vegetation, and
direct physical modifications can cause stream channel instability. Separating the differences
between anthropogenic versus geologic processes in channel adjustment is a key to prevention,
mitigation, and restoration of disturbed systems.
Rosgen (1996) has also created a river inventory hierarchy involving four levels that would allow
a stream assessment to be conducted at various levels, ranging from broad qualitative
descriptions to detailed quantitative descriptions. The idea is to provide documented
measurements, coupled with consistent, quantitative indices of stability, to make the approach to
stream assessments less subjective and more consistent and reproducible. Level I and Level II
are used to do the initial stratification of a reach by valley and stream type. Level III is used to
predict stability. Level IV is used for validation, and requires the greatest amount of detail over a
longer time period. For example, vertical stability and bank erosion can be estimated at Level III.
But, in a Level IV assessment, permanent cross-sections are revisited over time to verify shifts in
bed elevation and measure actual erosion that occurred.
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Chapter 7: Practices for Implementing Management Measures
The four hierarchal levels, and the measurements and determinations they include, are shown
below along with their objectives.
Level I—Geomorphic characterization: Used to describe generalized fluvial features using
remote sensing and existing inventories of geology, landform evolution, valley morphology,
depositional history and associated river slopes, relief and patterns utilized for generalized
categories of major stream types, and associated interpretations.
Level II—Morphological description: To delineate homogeneous stream types that describe
specific slopes, channel materials, dimensions and patterns from reference reach
measurements and provide a more detailed level of interpretation than Level I. Includes
measurements such as sinuosity, width/depth ration, slope, entrenchment ratio, and channel
patterns and material.
Level III—Stream "state" or condition: The "state" of streams further describes existing
conditions that influence the response of channels to imposed change and provide specific
information for prediction methodologies (such as stream bank erosion calculations).
Provides for very detailed descriptions and associated interpretation and predictions. Includes
such measurements and/or characterizations of vegetation, deposition, debris, meander
patterns, channel stability index, and flow regime.
LevelIV—Reach specific studies (validation level): Provides reach-specific information on
channel processes. Used to evaluate prediction methodologies; to provide sediment,
hydraulic and biological information related to specific stream types; and to evaluate
effectiveness of mitigation and impact assessments for activities by stream type. Involves
direct measurements of sediment transport, bank erosion rates, aggradation/degradation,
hydraulics, and biological data.
Rosgen's stream classification methodologies can assist in stream restoration design by:
• Enabling more precise estimates of quantitative hydraulic relationships associated with
specific stream and valley morphologies.
• Establishing guidelines for selecting stable stream types for a range of dimensions,
patterns, and profiles that are in balance with the river's valley slope, valley confinement,
depositional materials, streamflow, and sediment regime of the watershed.
• Providing a method for extrapolating hydraulic parameters and developing empirical
relationships for use in the resistance equations and hydraulic geometry equations needed
for restoration design.
• Developing a series of meander geometry relationships that are uniquely related to stream
types and their bankfull dimensions.
• Identifying the stable characteristics for a given stream type by comparing the stable form
to its unstable or disequilibrium condition.
Refer to Applied River Morphology (Rosgen, 1996) for more information on this stream
classification system and potential applications.
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Scheduling Projects
Often clearing and grading for a project can be scheduled
during the time of year that the erosion potential of the site
is relatively low. In many parts of the country, there is a
certain period of the year when erosion potential is
relatively low and construction scheduling could be very
effective. For example, in the Pacific region if construction
can be completed during the 6-month dry season (e.g., May
1 to October 31), temporary erosion and sediment controls
might not be needed. In some parts of the country erosion
potential is very high during certain parts of the year, such
as the spring thaw in northern and high-elevation areas.
During that time of year, snowmelt generates a constant
runoff that can erode soil. In addition, construction
vehicles can easily turn the soft, wet ground into mud,
which is more easily washed off-site. Therefore, in the
north, limitations could be placed on clearing and grading
during the spring thaw (Goldman et al., 1986).
Additional Resource
> CASQA. 2004. California Stormwater BMP Construction Handbook: Scheduling. California
Stormwater Quality Association, Sacramento, CA.
http://www. cabmphandbooks. com/Documents/Construction/EC-1 .pdf.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Sediment Basins/Rock Dams
An earthen or rock embankment that is located to capture
sediment from runoff and retain it on the construction site.
Sediment basins, also known as silt basins, are engineered
impoundment structures that allow sediment to settle out of
the urban runoff. They are installed prior to full-scale
grading and remain in place until the disturbed portions of
the drainage area are fully stabilized. They are generally
located at the low point of sites, away from construction
traffic, where they will be able to trap sediment-laden
runoff. Basin dewatering is achieved either through a
single riser and drainage hole leading to a suitable outlet on
the downstream side of the embankment or through the
gravel of the rock dam. In both cases, water is released at a
substantially slower rate than would be possible without
the control structure.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
The following are general specifications for sediment basin design criteria as presented in
Schueler(1997):
• Provide 1,800 to 3,600 ft3 of storage per contributing acre (a number of states, including
Maryland, Pennsylvania, Georgia, and Delaware, recently increased the storage
requirement to 3,600 ft3 or more [CWP, 1997b]).
• Surface area equivalent to 1 percent of drainage area (optional, seldom required).
• Riser with spillway capacity of 0.2 ft3/s/ac of drainage area (peak discharge for 2-year
storm with 1-foot freeboard).
• Length-to-width ratio of 2 or greater.
• Basin side slopes no steeper than 2:1 (h:v).
• Safety fencing, perforated riser, dewatering (optional, seldom required).
Sediment basins can be classified as either temporary or permanent structures, depending on the
length of service of the structure. If they are designed to function for less than 36 months, they
are classified as temporary; otherwise, they are considered permanent. Temporary sediment
basins can also be converted into permanent runoff management ponds. When sediment basins
are designed as permanent structures, they must meet all standards for wet ponds. It is important
to note that even the best-designed sediment basin seldom exceeds 60 to 75 percent total
suspended solids (TSS) removal, which should be considered when selecting a sediment control
practice.
Basins are most commonly used at the outlets of diversions, channels, slope drains, or other
runoff conveyances that discharge sediment-laden water.
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Additional Resources
^ CASQA. 2003. California Stormwater BMP Construction Handbook. Sediment Basin. California
Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/SE-2.pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Sediment Basin. Iowa State
University. http://www.ctre.iastate.edU/erosion/manuals/construction/3.17 sediment basin.pdf
^ Michigan Department of Environmental Quality. 1992. SESC Training Manual. Sedimentation
Basin. Michigan Department of Environmental Quality, Lansing, MI.
http://www.deq.state.mi.us/documents/deq-swq-nps-sb.pdf
^ Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Sediment Basin. Tennessee Department of Environment and Conservation, Nashville,
TN. http://state.tn.us/environment/wpc/sed ero controlhandbook/sb.pdf
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Sediment Fences
Silt fence, also known as filter fabric fence, is available in
several mesh sizes from many manufacturers. Sediment is
filtered out as runoff flows through the fabric. Such fences
should be used only where there is sheet flow (no
concentrated flow), and the maximum drainage area to the
fence should be 0.5 acre or less per 100 feet offence. To
ensure sheet flow, a gravel collar or level spreader can be
used upslope of the fence. Many types of fabrics are
available commercially. The characteristics that determine
a fence's effectiveness include filtration efficiency,
permeability, tensile strength, tear strength, ultraviolet
resistance, pH effects, and creep resistance. The longevity
of silt fences depends heavily on proper installation and
maintenance, however they typically last 6 to 12 months.
CWP (1997d) identified several conditions that increase
the effectiveness of silt fences:
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
• The length of the slope does not exceed 50 feet for slopes of 5 to 10 percent, 25 feet for
slopes of 10 to 20 percent, or 15 feet for slopes greater than 20 percent.
• The silt fence is aligned parallel to the slope contours.
• Edges of the silt fence are curved uphill, which does not allow flow to bypass the fence.
• The contributing length to the fence is less than 100 feet.
• The fence has reinforcement if receiving concentrated flow.
• The fence was installed above an outlet pipe or weir.
• The fence is down slope of the exposed area and alignment considers construction traffic.
• Sediment is not allowed to accumulate behind the fence (increases capacity and decreases
breach potential).
• Alignment of the silt fence mirrors the property line or limits of disturbance.
Additional Resources
> CASQA. 2003. California Stormwater BMP Construction Handbook: Straw Bale Barrier.
California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/SE-9.pdf.
> ISU. 2006. Iowa Construction Site Erosion Control Manual: Sediment Barrier. Iowa State
University. http://www.ctre.iastate.edU/erosion/manuals/construction/3.16 sediment barrier.pdf.
> Missouri Department of Natural Resources. 2006. Protecting Water Quality, A Construction Site
Water Quality Field Guide: Sediment Fence. Missouri Department of Natural Resources.
http://www.dnr.mo.gov/env/wpp/field-guide/fg05 06 sedimentcontrol.pdf.
^ Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Silt Fence. Tennessee Department of Environment and Conservation, Nashville, TN.
http://state.tn.us/environment/wpc/sed ero controlhandbook/sf.pdf.
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Sediment Traps
Sediment traps are small impoundments that allow
sediment to settle out of runoff water. They are typically
installed in a drainage way or other point of discharge
from a disturbed area. Temporary diversions can be used
to direct runoff to the sediment trap. Sediment traps are
ideal for sites 1 acre and smaller and should not be used
for areas greater than 5 acres. They typically have a useful
life of approximately 18 to 24 months. A sediment trap
should be designed to maximize surface area for
infiltration and sediment settling. This design increases
the effectiveness of the trap and decreases the likeliness
of backup during and after periods of high runoff
intensity. The approximate storage capacity of each trap
should be at least 1,800 ft3/acre of disturbed land draining
into the trap (Smolen et al., 1988).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Additional Resources
> British Columbia Ministry of Agriculture, Food and Fisheries. 2004. Constructed Ditch Fact Sheet:
Sediment Traps. No. 9. http://www.agf.gov.bc.ca/resmgmt/publist/600Series/641310-1 .pdf.
> CASQA. 2003. California Stormwater BMP Construction Handbook. Sediment Traps. California
Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.com/Documents/Construction/SE-3.pdf.
> Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Sediment Trap. Tennessee Department of Environment and Conservation, Nashville,
TN. http://www.state.tn.us/environment/wpc/sed ero controlhandbook/st.pdf.
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Seeding
Seeding establishes a vegetative cover on disturbed areas
and is very effective in controlling soil erosion once a dense
vegetative cover has been established. Seeding establishes
permanent erosion control in a relatively short amount of
time and has been shown to decrease solids load by 99
percent (CWP, 1997a). The three most common seeding
methods are (1) broadcast seeding, in which seeds are
scattered on the soil surface; (2) hydroseeding, in which
seeds are sprayed on the surface of the soil with a slurry of
water; and (3) drill seeding, in which a tractordrawn
implement injects seeds into the soil surface. Broadcast
seeding is most appropriate for small areas and for
augmenting sparse and patchy grass covers. Hydroseeding is
often used for large areas (in excess of 5,000 square feet)
and is typically combined with tackifiers, fertilizers, and
fiber mulch. Drill seeding is expensive and is cost-effective
only on sites greater than 2 acres. For best results, bare soils should be seeded or otherwise
stabilized within 15 calendar days after final grading. Denuded areas that are inactive and will be
exposed to rain for 15 days or more can also be temporarily stabilized, usually by planting seeds
and establishing vegetation during favorable seasons in areas where vegetation can be
established. In very flat, nonsensitive areas with favorable soils, stabilization may involve simply
seeding and fertilizing. The Soil Quality Institute (SQI, 2000) recommends that soils that have
been compacted by grading should be broken up or tilled before vegetating.
To establish a vegetative cover, it is important to use seeds from adapted plant species and
varieties that have a high germination capacity. Supplying essential plant nutrients, testing the
soil for toxic materials, and applying an adequate amount of lime and fertilizer can overcome
many unfavorable soil conditions and establish adequate vegetative cover. Specific information
about seeds, various species, establishment techniques, and maintenance can be obtained from
Erosion Control & Conservation Plantings on Noncropland (Landschoot, 1997) or a local
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Cooperative State Research, Education, and Extension Service
Conservation Service12 office.
11
or Natural Resources
Additional Resources
> CASQA. 2003. California Stormwater BMP Construction Handbook: Hydroseeding. California
Stormwater Quality Association, Sacramento, CA.
http://www.cabrnphandbooks.corn/Docurnents/Construction/EC-4.pdf.
^ Wisconsin Department of Natural Resources. 2003. Seeding for Construction Site Erosion
Control. Wisconsin Department of Natural Resources, Madison, WI.
http://dnr.wi.gov/org/water/wm/nps/pdf/stormwater/techstds/erosion/
Seeding%20For%20Construction%20Site%20Erosion%20Control%20 1059.pdf.
11 http://www.csrees.usda.gov
12 http://www.nrcs.usda.gov
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Selective Withdrawal
Temperature control in reservoir releases depends on the
volume of water storage in the reservoir, the timing of the
release relative to storage time, and the level from which
the water is withdrawn. Dams capable of selectively
releasing waters of different temperatures can provide
cooler or warmer water temperatures downstream at times
that are critical for other instream resources, such as
during periods offish spawning and development of fry
(Fontane et al., 1981; Hansen and Crumrine, 1991).
Stratified reservoirs are operated to meet downstream
temperature objectives such as to enhance a cold-water or
warm-water fishery or to maintain preproject stream
temperature conditions. Release temperature may also be
important for irrigation (Fontane et al., 1981).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Multilevel intake devices in storage reservoirs allow
selective withdrawal of water based on temperature and DO levels. These devices minimize the
withdrawal of surface water high in blue-green algae, or of deep water enriched in iron and
manganese. Care should be taken in the design of these systems not to position the multilevel
intakes too far apart because this will increase the difficulty with which withdrawals can be
controlled, making the discharge of poor-quality hypolimnetic water more likely (Howington,
1990; Johnson and LaBounty, 1988; Smith et al., 1987).
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Chapter 7: Practices for Implementing Management Measures
Setbacks
Where setbacks have been implemented to reduce the
hazard of coastal land loss, they have also included
requirements for the relocation of existing structures
located within the designated setback area. Setbacks can
also include restrictions on uses of waterfront areas that are
not related to the construction of new buildings (Davis,
1987). Upland drainage from development should be
directed away from bluffs and banks so as to avoid
accelerating slope erosion.
In most cases, states have used the local unit of
government to administer the program on either a
mandatory or voluntary basis. This allows local
government to retain control of its land use activities and to
exceed the minimum state requirements if this is deemed
desirable (NRC, 1990).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
D Integrated
0 Planning & regulatory
Technical standards for defining and delineating setbacks also vary from state to state. One
approach is to establish setback requirements for any "high hazard area" eroding at greater than 1
foot per year. Another approach is to establish setback requirements along all erodible shores
because even a small amount of erosion can threaten homes constructed too close to the
streambank or shoreline. Several states have general setback requirements that, while not based
on erosion hazards, have the effect of limiting construction near the streambank or shoreline.
The basis for variations in setback regulations between states seems to be based on several
factors, including (NRC, 1990):
• The language of the law being enacted
• The geomorphology of the coast
• The result of discretionary decisions
• The years of protection afforded by the setback
• Other variables decided at the local level of government
From the perspective of controlling NFS pollution resulting from erosion of shorelines and
streambanks, the use of setbacks has the immediate benefit of discouraging concentrated flows
and other impacts of storm water runoff from new development in areas close to the streambank
or shoreline. In particular, the concentration of storm water runoff can aggravate the erosion of
shorelines and streambanks, leading to the formation of gullies, which are not easily repaired.
Therefore, drainage of storm water from developed areas and development activities located
along the shoreline should be directed inland to avoid accelerating slope erosion.
The most significant NFS benefits are provided by setbacks that not only include restrictions on
new construction along the shore but also contain additional provisions aimed at preserving and
protecting coastal features such as beaches, wetlands, and riparian forests. This approach
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Chapter 7: Practices for Implementing Management Measures
promotes the natural infiltration of surface water runoff before it passes over the edge of the bank
or bluff and flows directly into the coastal waterbody. Setbacks also help protect zones of
naturally occurring vegetation growing along the shore. As discussed in the section on
"bioengineering practices," the presence of undisturbed shoreline vegetation itself can help to
control erosion by removing excess water from the bank and by anchoring the individual soil
particles of the substrate.
Almost all states and territories with setback regulations have modified their original programs to
improve effectiveness or correct unforeseen problems (NRC, 1990). Experiences have shown
that procedures for updating or modifying the setback width need to be included in the
regulations. For instance, application of a typical 30-year setback standard in an area whose rate
of erosion is 2 feet per year results in the designation of a setback width of 60 feet. This width
may not be sufficient to protect the beaches, wetlands, or riparian forests whose presence
improves the ability of the streambank or shoreline to respond to severe wave and flood
conditions, or to high levels of surface water runoff during extreme precipitation events. A
setback standard based on the landward edge of streambank or shoreline vegetation is one
alternative that has been considered (NRC, 1990; Davis, 1987).
From the standpoint of NFS pollution control, an approach that designates streambanks,
shorelines, wetlands, beaches, or riparian forests as a special protective feature, allows no
development on the feature, and measures the setback from the landward side of the feature is
recommended (NRC, 1990). In some cases, provisions for soil bioengineering, marsh creation,
beach nourishment, or engineering structures may also be appropriate since the special protective
features within the designated setbacks can continue to be threatened by uncontrolled erosion of
the shoreline or streambank. Finally, setback regulations should recognize that some special
features of the streambank or shoreline will change position. For instance, beaches and wetlands
can be expected to migrate landward if water levels continue to rise. Alternatives for managing
these situations include flexible criteria for designating setbacks, vigorous maintenance of
beaches and other special features within the setback area, and frequent monitoring of the rate of
streambank or shoreline erosion and corresponding adjustment of the setback area.
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Shoreline Sensitivity Assessment
Currently there are no complete, universal assessment
methodologies that apply to all shorelines and assess
erosion vulnerabilities in various types of lakes, reservoirs,
estuaries, and coasts. The methods presented by NOAA
and the U.S. Geological Survey (USGS) were originally
developed for other purposes and are being applied for
other shoreline assessments:
• Environmental Sensitivity Mapping
• USGS Coastal Classification (Coastal & Marine
Geology Program)
• Coastal Vulnerability Index (CVI) (focus is on
SLR—the "erosion" factor may be the only
relevant factor in CVI)
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks 0 Shorelines
D Vegetative
D Structural
D Integrated
0 Planning & regulatory
Environmental Sensitivity Mapping
The Environmental Sensitivity Index (ESI) was originally created for NOAA to prioritize areas
for environmental cleanup (mainly oil-spills), to assist spill-response coordinators in evaluating
the potential impact of oil along a shoreline, and to facilitate the allocation of resources during
and after a spill.
ESI maps are comprised of three general types of information (NOAA, 1997):
• Shoreline Classification—ranked according to a scale relating to sensitivity, natural
persistence of oil, and ease of cleanup.
• Biological Resources—including oil-sensitive animals and rare plants as well as habitats
that are used by oil-sensitive species or are themselves sensitive to oil spills, such as
submersed aquatic vegetation and coral reefs.
• Human-Use Resources—specific areas that have added sensitivity and value because of
their use, such as beaches, parks and marine sanctuaries, water intakes, and
archaeological sites.
The standardized ESI shoreline guideline rankings include estuarine, lacustrine, riverine, and
palustrine habitats (NOAA, 1997). The classification scheme is based on an understanding of the
physical and biological character of the shoreline environment, not just the substrate type and
grain size. Relationships among physical processes, substrate type, and associated biota produce
specific geomorphic/ecologic shoreline types, sediment transport patterns, and predictable
patterns in oil behavior and biological impact. The concepts relating natural factors to the
relative sensitivity of coastline, mostly developed in the estuarine setting, were slightly modified
for lakes and rivers. The sensitivity ranking is controlled by the following factors:
• Relative exposure to wave and tidal energy
• Shoreline slope
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• Substrate type (grain size, mobility, penetration and/or burial, and trafficability)
• Biological productivity and sensitivity
ESI maps have proven to have a long-term use, and they are excellent tools for studying
shoreline change and its effects on the distribution and concentration of plants and animals living
near the coast. Environmental sensitivity mapping is still evolving, and NO A A researchers are
working with federal, state, and private industry partners to improve the ESI mapping system to
extend beyond spill response.
USGS Coastal Classification (Coastal & Marine Geology Program)
The objective of the Coastal Classification Map is to determine the hazard vulnerability of an
area. The coastal geomorphic classification scheme utilizes morphology and human
modifications of the coast as the primary basis for hazard assessment. It emphasizes physical
factors that influence erosion, overwash of sandy beaches and barrier islands, and landward
sediment transport during storms along and across those features (USGS, 2004).
USGS National Assessment of Coastal Vulnerability to Sea-Level Rise
The USGS Coastal and Marine Geology Program's National Assessment, seeks to determine the
relative risks due to future sea-level rise for the U.S. Atlantic, Pacific, and Gulf of Mexico coasts
USGS, 2002). Through the use of a CVI, the relative risk that physical changes will occur as sea-
level rises is quantified based on the following criteria: tidal range, wave height, coastal slope,
shoreline change, geomorphology, and historical rate of relative sea-level rise. This approach
combines a coastal system's susceptibility to change with its natural ability to adapt to changing
environmental conditions, and yields a relative measure of the system's natural vulnerability to
the effects of sea-level rise.
In 2001, USGS in partnership with the National Park Service (NFS) Geologic Resources
Division, began conducting hazard assessments and creating map products to assist the NFS in
managing vulnerable coastal resources. One of the most important and practical issues in coastal
geology is determining the physical response of coastal environments to water-level changes.
Additional Resources
> NOAA. 1997. Environmental Sensitivity Index Guidelines (Version 3) Chapter 2. Seattle, WA.
http://response.restoration.noaa.gov/book shelf/876 chapter2.pdf.
> USGS. 2002. Vulnerability of US National Parks to Sea-Level Rise and Coastal Change. U. S.
Geological Survey, http://pubs.usgs.gov/fs/fs095-02/fs095-02.html.
> USGS. 2004. Coastal Classification Mapping Project. U.S. Geological Survey, Coastal &
Marine Geology Program, http://coastal.er.usgs.gov/coastal-classification/class.html.
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Chapter 7: Practices for Implementing Management Measures
Site Fingerprinting
Often areas of a construction site are unnecessarily
cleared. The total amount of disturbed area can be
reduced with site fingerprinting, which involves placing
development in the most environmentally sound locations
on the site and minimizing the size of disturbed area.
With site fingerprinting, only those areas essential for
completing construction activities are cleared. The
remaining area is left undisturbed.
Fingerprinting places development away from
environmentally sensitive areas (wetlands, steep slopes,
etc.), areas for future open space and restoration, areas
where trees are to be saved, and temporary and permanent
vegetative buffer zones.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
The proposed limits of land disturbance can be physically
marked off to ensure that only the land area required for buildings, roads, and other infrastructure
is cleared. Existing vegetation, especially vegetation on steep slopes, can be avoided.
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Chapter 7: Practices for Implementing Management Measures
Sodding
Sodding permanently stabilizes an area with a thick
vegetative cover. Sodding provides immediate stabilization
of an area and can be used in critical areas or where
establishing permanent vegetation by seeding and
mulching would be difficult. Sodding is also a preferred
option when there is high erosion potential during the
period of vegetative establishment from seeding.
According to the Soil Quality Institute (SQI, 2000), soils
that have been compacted by grading should be broken up
or tilled before placing sod.
Additional Resources
^ Barr Engineering Company. 2001. Minnesota Urban
Small Sites BMP Manual: Stormwater Best Management
Practices for Cold Climates. Soil Erosion Control:
Vegetative Methods. Prepared for the Metropolitan
Council by Barr Engineering Company, St. Paul, MN.
http://www.metrocouncil.org/environmentAVatershed/BMP/CH3 RPPSoilVeget.pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Sodding. Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/2.6 sodding.pdf.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Soil Protection
Unprotected stockpiles are very prone to erosion, and they
must be protected. Small stockpiles can be covered with a
tarp to prevent erosion. Large stockpiles can be stabilized
by erosion blankets, seeding, or mulching.
Because of the high organic content of topsoil, it is not
recommended for use as fill material or under pavement.
After a site is cleared, the topsoil is typically removed.
Since topsoil is essential to establish new vegetation, it
should be stockpiled and then reapplied to the site for
revegetation, if appropriate. Although topsoil salvaged
from the existing site can often be used, it must meet
certain standards, and topsoil might need to be imported
onto the site if the existing topsoil is not adequate for
establishing new vegetation.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Spill and Water Budgets
Although often used together, spill and water budgets are
independent methods of facilitating downstream fish
migration. Spill budgets provide alternative methods for
fish passage that are less dangerous than passage through
turbines. Spillways are used to allow fish to leave the
reservoir by passing over the dam rather than through the
turbines. The spillways must be designed to ensure that
hydraulic conditions do not induce injury to the passing
fish from scraping and abrasion, turbulence, rapid pressure
changes, or supersaturation of dissolved gases in water
passing through plunge pools (Stone and Webster, 1986).
In the Columbia River basin (Pacific Northwest), the
USAGE provides spill on a limited basis to pass fish
around specific dams to improve survival rates. At key
dams, spill is used in special operations to protect hatchery
releases or provide better passage conditions until bypass systems are fully developed or, in
some cases, improved (van der Borg and Ferguson, 1989). The cost of this alternative depends
on the volume of water lost for power production (Mattice, 1990). Analyses of this practice,
using a USAGE model called FISHPASS, historically has shown that application of spill budgets
in the Columbia River basin is consistently the most costly and least efficient method of
improving overall downstream migration efficiency (Dodge, 1989).
In 1995 the National Marine Fisheries Service (NMFS) released a draft biological opinion to
save Columbia River Basin salmon. The opinion was issued after concluding that current
operations of the hydropower system were jeopardizing Columbia Basin salmon. The opinion
addresses safer passage for young fish through the dams and modification to a number of
hydropower operations and facilities. It calls for using as much water as possible during fish-
passage season to improve flow for fish moving through the system. Specifically the draft called
for spilling water over dams to increase passage of juvenile salmon via non-turbine routes to at
least 80 percent. The USAGE now runs the Juvenile Fish Transportation Program in cooperation
with NMFS (NOAA, 1995; USACE, 2002b).
Water budgets increase flows through dams during the out-migration of anadromous fish species.
They are used to speed smolt migration through reservoirs and dams. Water normally released
from the impoundment during the winter period to generate power is instead released in May or
June, when it can be sold only as secondary energy. This concept has been used in some regions
of the United States, although quantification of the overall benefits is lacking (Dodge, 1989).
The volume of a typical water budget is generally not adequate to sustain minimum desirable
flows for fish passage during the entire migration period. The Columbia Basin Fish and Wildlife
Authority has proposed replacement of the water budget on the Columbia River system with a
minimum flow requirement to prevent problems of inadequate water volume in discharge during
low-flow years (Muckleston, 1990).
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Chapter 7: Practices for Implementing Management Measures
Spill Prevention and Control Program
Spill procedure information can be posted, and persons
trained in spill handling should be onsite or on call at all
times. Materials for cleaning up spills can be kept onsite
and easily available. Spills should be cleaned up
immediately and the contaminated material properly
disposed.
In general, a spill prevention, control, and countermeasure
(SPCC) plan can include guidance to site personnel on:
• Proper notification when a spill occurs
• Site responsibility with respect to addressing the
cleanup of a spill
• Stopping the source of a spill
• Cleaning up a spill
• Proper disposal of materials contaminated by the spill
• Location of spill response equipment programs
• Training program for designated on-site personnel
A periodic spill "fire drill" can be conducted to help train personnel on proper responses to spill
events and to keep response actions fresh in the minds of personnel. It is important to maintain
an adequate spill and cleaning kit, which could include the following:
• Detergent or soap, hand cleaner, and water
• Activated charcoal, adsorptive clay, vermiculite, kitty litter, sawdust, or other adsorptive
materials
• Lime or bleach to neutralize pesticides or other spills in emergency situations
• Tools such as a shovel, broom, and dustpan and containers for disposal
• Proper protective clothing
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
0 Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Spillway Modifications
Spill at hydroelectric dams is routinely required during
periods of high runoff when the river discharge exceeds
what can be passed through the powerhouse turbines. In
some cases, spill has been associated with gas
supersaturation problems. The USAGE has proposed
several practices for solving the gas supersaturation
problem. These include (1) passing more headwater
storage through turbines, installing new fish bypass
structures, and installing additional power units to reduce
the need for spill; (2) incorporating "flip-lip" deflectors in
spillway-stilling basins, transferring power generation to
high-dissolved-gas-producing dams, and altering spill
patterns at individual dams to minimize nitrogen mass
entrainment; and (3) collecting and transporting juvenile
salmonids around affected river reaches. Only a few of
these practices have been implemented (Tanovan, 1987).
As more attention is being paid to maintaining minimum flows in rivers for fish passage and
spawning, mangers are balancing the need for spills with the potential impacts of gas
supersaturation (Anderson, 2004; Anderson, 1995; DeHart, 2003; USFWS, 2001; Van Holmes
and Anderson, 2004). For example, the U.S. Fish and Wildlife Service has routinely monitored
gas supersaturation in reaches below Bonneville Dam (Columbia River, Oregon) to protect
migrating salmon, many of which are endangered species (USFWS, 2001).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
0 Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Surface Roughening
Roughening is the scarifying of a bare sloped soil surface
with horizontal grooves or benches running across the
slope. Roughening aids the establishment of vegetative
cover, improves water infiltration, and decreases runoff
velocity.
Additional Resource
> Tennessee Department of Environment and
Conservation. 2002. Erosion and Sediment Control
Handbook: Surface Roughening. Tennessee Department
of Environment and Conservation, Nashville, TN.
http://www.state.tn.us/environment/wpc/
sed ero controlhandbook/sr.pdf.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Toe Protection
A number of qualitative advantages are to be gained by
providing toe protection for vertical bulkheads. Toe
protection usually takes the form of a stone apron installed
at the base of the vertical structure to reduce wave
reflection and scour of bottom sediments during storms.
The installation of rubble toe protection should include
filter cloth and perhaps a bedding of small stone to reduce
the possibility of rupture of the filter cloth. Ideally, the
rubble should extend to an elevation such that waves will
break on the rubble during storms.
Additional Resources
> Massachusetts DEP. 2006. Massachusetts Nonpoint
Source Pollution Management Manual: Stone Toe
Protection. Massachusetts Department of Environmental
Protection, Boston, MA.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
http://proiects.geosvntec.com/NPSManual/Fact%20Sheets/Stone%20Toe%20Protection.pdf.
Wisconsin Department of Natural Resources. 2006. Vegetated Armoring Erosion Control
Methods, http://dnr.wi.gov/org/water/fhp/waterwav/erosioncontrol-vegetated.html.
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Chapter 7: Practices for Implementing Management Measures
Training—ESC
Provide education and training opportunities for
designers, developers, and contractors. One of the most
important factors determining whether ESCs will be
properly installed and maintained on a construction site is
the knowledge and experience of the contractor and onsite
personnel. Many communities require certification for
key on-site employees who are responsible for
implementing the ESC plan. Certification can be
accomplished through municipally sponsored training
courses; more informally, municipalities can hold
mandatory preconstruction or prewintering meetings and
conduct regular and final inspection visits to transfer
information to contractors (Brown and Caraco, 1997).
Information that can be covered in training courses and
meetings includes the importance of ESC for water
quality protection; developing and implementing ESC
plans; the importance of proper installation, regular inspection,
practices; and record keeping for inspections and maintenance
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
and diligent maintenance of ESC
activities.
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Chapter 7: Practices for Implementing Management Measures
Transference of Fish Runs
Transference offish runs involves inducing anadromous
fish species to use different spawning grounds in the
vicinity of an impoundment. To implement this practice,
the nature and extent of the spawning grounds that were
lost due to the blockage in the river need to be assessed,
and suitable alternative spawning grounds need to be
identified. The feasibility of successfully collecting the fish
and transporting them to alternative tributaries also needs
to be carefully determined.
One strategy for mitigating the impacts of diversions on
fisheries is the use of ephemeral streams as conveyance
channels for all or a portion of the diverted water. If flow
releases are controlled and uninterrupted, a perennial
stream is created, along with new instream and riparian
habitat. However, the biota that had been adapted to
preexisting conditions in the ephemeral stream will probably be eliminated.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
0 Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Tree Armoring, Fencing, and Retaining Walls
or Tree Wells
Tree armoring protects tree trunks and natural vegetation
from being damaged by construction equipment. Fencing
can also protect tree trunks, but it should be placed at the
tree's drip line so that construction equipment is kept
away from the tree. A tree's drip line is the minimum area
around the tree in which the tree's root system should not
be disturbed by cut, fill, or soil compaction caused by
heavy equipment. When cutting or filling must be done
near a tree, a retaining wall or tree well can be used to
minimize the cutting of the tree's roots or the quantity of
fill placed over the tree's roots. It is recommended that
cutting or filling be done only when absolutely necessary.
Fill placement over the tree root flare or within the
dripline will eventually kill the tree.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
TREE REVETMENT
— Steel Cable
Clamp
Tree Revetments
Tree revetments consist of a row of interconnected trees
anchored to the toe of the streambank or to the upper
streambank (Figures 7.28 and 7.29). This serves to reduce
flow velocities along eroding streambanks, trap sediment,
and provide a substrate for plant establishment and erosion
control. This design relies on the installation of an
adequate anchoring system and is best suited for
streambank heights under 12 feet and bankfull velocities
under 6 feet per second. In addition, this structure should
occupy no more than 15 percent of the channel at bankfull.
Toe protection is needed to accompany this design if scour
is anticipated and upper bank soil bioengineering
techniques are recommended to ensure streamside
regeneration. This design allows for the use of local
materials if they are readily available. Decay resistant
species are
recommended for the
logs to extend the life
of the structure and
thus the ability of
vegetation to become
established. Due to
decomposition,
these structures have
a limited life and
might require
periodic replacement.
It is considered
beneficial that
decomposition of the
logs over time allows
the streambank to
return to a natural
state with protection
provided by mature
streambank
vegetation. There is a
potential for the logs to dislodge, and these structures should not be located upstream of bridges
or other structures sensitive to damage. Tree revetments are susceptible to damage by ice
(FISRWG, 1998). Installation guidelines are available from the USDA-FS Soil Bioengineering
Guide (USDA-FS, 2002).
Deadman,
or Stump
&'-& Long
Deadman
Figure 7.28 Tree Revetment (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Additional Resources
^ Alaska Department of Fish and Game. 2005. Spruce Tree Revetment.
http://www.sf.adfg.state.ak.us/sarr/restoration/techniques/images/csbs strevet.pdf
> FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda. gov/technical/stream_restoration/PDFFILES/APPE]S[DIX.pdf
^ Goard, D. 2006. Riparian Forest Best Management Practices: Tree Revetments. Kansas State
University, Manhattan, KS. http://www.oznet.ksu.edu/library/forst2/MF2750.pdf
> Gough, S. 2004. Tree Revetments for Streambank Revi talization. Missouri Department of
Conservation, Fisheries Division, Jefferson City, MO. http://mdc.mo.gov/fish/streams/revetmen/.
TREE REVETMENT: SECTION VIEW
(Not to scale)
Existing
vegetation,
plantings, or soil
pioengineering
techniques •
Second Row of
Revetment Added
Deadman
or Earth
Anchor
15' to 20'
from Bank
to Deadman
Figure 7.29 Tree Revetment: Section View (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Turbine Operation
Implementation of changes in the turbine start-up
procedures can also enlarge the zone of withdrawal to
include more of the epilimnetic waters in the downstream
releases. Monitoring of the releases at the Walter F.
George lock and dam (Chattahoochee River, Georgia),
showed levels of DO declined sharply at the start-up of
hydropower production. The severity and duration of the
DO drop were found to be reduced by starting up all the
generator units within a minute of each other (Findley and
Day, 1987).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Turbine Venting
Turbine venting is the practice of injecting air into water as
it passes through a turbine. If vents are provided inside the
turbine chamber, the turbine will aspirate air from the
atmosphere and mix it with water passing through the
turbine as part of its normal operation. In early designs, the
turbine was vented through existing openings, such as the
draft tube opening or the vacuum breaker valve in the
turbine assembly. Air forced by compressors into the draft
tube opening enriched reservoir waters with little
detectable DO to concentrations of 3 to 4 mg/L. Overriding
the automatic closure of the vacuum breaker valve (at high
turbine discharges) increased DO by only 2 mg/L
(Harshbarger, 1987).
Turbine venting uses the low-pressure region just below
the turbine wheel to aspirate air into the discharges (Wilhelms, 1984). Autoventing turbines are
constructed with hub baffles, or deflector plates placed on the turbine hub upstream of the vent
holes to enhance the low-pressure zone in the vicinity of the vent and thereby increase the
amount of air aspirated through the venting system. Turbine efficiency relates to the amount of
energy output from a turbine per unit of water passing through the turbine. Efficiency decreases
as less power is produced for the same volume of water. In systems where the water is aerated
before passing through the turbine, part of the water volume is displaced by the air, thus leading
to decreased efficiency. Hub baffles have also been added to autoventing turbines at the Norris
Dam (Clinch River, Tennessee) to further improve the DO levels in the turbine releases (Jones
and March, 1991).
Developments in autoventing turbine technology show that it may be possible to aspirate air with
no resulting decrease in turbine efficiency. In one test of an autoventing turbine at the Norris
Dam, the turbine efficiency increased by 1.8 percent (March et al., 1991; Waldrop, 1992).
Technologies like autoventing turbines are very site-specific and outcomes will vary
considerably.
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Chapter 7: Practices for Implementing Management Measures
Vegetated Buffers
Like filter strips, vegetated buffers provide a physical
separation between a construction site and a waterbody.
The difference between a filter strip and a vegetated buffer
area is that a filter strip is an engineered device, whereas a
buffer is a naturally occurring filter system. Vegetated
buffers remove nutrients and other pollutants from runoff,
trap sediments, and shade the waterbody to optimize light
and temperature conditions for aquatic plants and animals
(Welsch, n.d.). Preservation of vegetation for a buffer can
be planned before any site-disturbing activities begin so as
to minimize the impact of construction activities on
existing vegetation. Trees can be clearly marked at the
dripline to preserve them and to protect them from ground
disturbances around the base of the tree.
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
0 Vegetative
D Structural
D Integrated
D Planning & regulatory
Proper maintenance of buffer vegetation is important. Maintenance requirements depend on the
plant species chosen, soil types, and climatic conditions. Maintenance activities typically include
fertilizing, liming, irrigating, pruning, controlling weeds and pests, and repairing protective
markers (e.g., fluorescent fences and flags).
Additional Resources
> CASQA. 2003. California Stormwater BMP Construction Handbook: Vegetated Buffer Strips.
California Stormwater Quality Association, Sacramento, CA.
http://www.cabmphandbooks.corri/Docurnents/Developrnent/TC-31 .pdf.
^ Ohio DNR. No date. Ohio Stream Management Guide: Forested Buffer Strips. Ohio Department
of Natural Resources, http://www.ohiodnr. com/water/pubs/fs st/stfs 13 .htm.
> River Alliance of Wisconsin. No date. Benefits of Vegetated Buffers. River Alliance of
Wisconsin, Madison, WI. http://www.wisconsmrivers.org/documents/policy/
Fact%20Sheet%20-%20Benefits%20of%20Vegetated%20Buffers.pdf.
^ Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Vegetative Practices. Tennessee Department of Environment and Conservation,
Nashville, TN.
http://state.tn.us/environment/wpc/sed ero controlhandbook/2.%20Vegetative%20Practices.pdf.
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Chapter 7: Practices for Implementing Management Measures
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
0 Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
Vegetated Filter Strips
Vegetated filter strips are low-gradient vegetated areas that
filter overland sheet flow. Runoff must be evenly
distributed across the filter strip. Channelized flows
decrease the effectiveness of filter strips. Level spreading
devices are often used to distribute the runoff evenly across
the strip (Dillaha et al., 1989).
Vegetated filter strips should have relatively low slopes
and adequate length to provide optimal sediment control
and should be planted with erosion-resistant plant species.
The main factors that influence the removal efficiency are
the vegetation type, soil infiltration rate, and flow depth
and travel time. These factors are dependent on the
contributing drainage area, slope of strip, degree and type
of vegetative cover, and strip length. Maintenance
requirements for vegetated filter strips include sediment
removal and inspections to ensure that dense, vigorous vegetation is established and concentrated
flows do not occur. For more information on vegetated filter strips, refer to EPA's National
Management Measures to Protect and Restore Wetlands and Riparian Areas for the Abatement
of Nonpoint Source Pollution (USEPA, 2005b).
Additional Resources
> ISU. 2006. Iowa Construction Site Erosion Control Manual: Vegetative Filter Strip. Iowa State
University. http://www.ctre.iastate.edU/erosion/manuals/construction/2.8 veg filter strip.pdf.
^ Leeds, R., L.C. Brown, M.R. Sulc, and L. VanLieshout. No date. Vegetative Filter Strips:
Application, Installation and Maintenance. The Ohio State University, Food, Agriculture and
Biological Engineering, Columbus, OH. http://ohiolme.osu.edu/aex-fact/0467.html.
> USD A. 2003. Grass Filter Strips. U.S. Department of Agriculture, Natural Resources
Conservation Service.
http://www.oh.nrcs.usda.gov/programs/Lake Erie Buffer/filter strips.html.
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Chapter 7: Practices for Implementing Management Measures
Vegetated Gabions
Vegetated gabions (Figure 7.30) start with wire-mesh,
rectangular baskets filled with small to medium rock and
soil. The baskets are then laced together to form a
structural toe or sidewall. Live branches (0.5 to 1 inch in
diameter) are then placed on each consecutive layer
between the rock filled baskets to take root, join together
the structure, and bind it to the slope. This method is
effective for protecting steep slopes where scouring or
undercutting is occurring. However, this method is not
appropriate in streams with heavy bed load or where severe
ice damage occurs. This method provides moderate
structural support and should be placed at the base of a
slope to stabilize the slope and reduce slope steepness. A
stable foundation is required for the installation of these
structures. When the rock size needed is not locally
available, this design is effective because
smaller rocks can be used. A limiting
factor of this method is that it is
expensive to install and to replace. These
structures are relatively expensive to
construct and frequently require costly
repairs. This method should be combined
with other soil bioengineering
techniques, particularly revegetation
efforts, to achieve a comprehensive
streambank restoration design (FISRWG,
1998). There is often opposition to these
structures based on their inability to
blend in with natural settings and their
general lack of aesthetically pleasing
qualities (Gore, 1985).
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Installation guidelines are available from
the USD A NRCS Engineering Field
Handbook, Chapter 18 (USDA-NRCS,
1992). Under EMRRP, the USAGE has
presented research on vegetated gabions
in a technical note (Gabions for
Streambank Erosion Control)1^
VEGETATED GABIONS
Slope for
toe wall
Willow, alder, or
poplar cuttings -
as brush layers
Slope for
toe bench
£j- Original
/' / slope
• Temporary
excavation
line
Tree/shrub cuttings
along horizontal
joints between bays
of gabion mattress
\
* T
Tree/shrub
cuttings along
vertical joints
Figure 7.30 Vegetated Gabion (Allen and Leech, 1997)
13
http://el.erdc.usace.army.mil/elpubs/pdf/sr22.pdf
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Chapter 7: Practices for Implementing Management Measures
Additional Resources
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
^ ISU. 2006. Iowa Construction Site Erosion Control Manual: Gabion. Iowa State University.
http://www.ctre.iastate.edU/erosion/manuals/construction/3.8_gabion.pdf.
^ Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Vegetated Rock Gabions/Gabions. Created for United
States Department of Agriculture, Natural Resource Conservation Service, Watershed Science
Institute. http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/veg rockgabions.pdf
> MMG Civil Engineering Systems, Ltd. 2001. Vegetated Gabions. MMG Civil Engineering
Systems, Ltd., St. Germans, Kings Lynn, Norfolk, England.
http://www.verdantsolutions.ltd.uk/acrobat/vegsod.pdf
^ Ohio DNR. No date. Ohio Stream Management Guide: Gabion Revetments. Ohio Department of
Natural Resources, http://www.ohiodnr.com/water/pubs/fs st/stfs 15.htm.
> Tennessee Department of Environment and Conservation. 2002. Erosion and Sediment Control
Handbook: Gabion. Tennessee Department of Environment and Conservation, Nashville, TN.
http://state.tn.us/environment/wpc/sed ero controlhandbook/ga.pdf
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Vegetated Geogrids
Vegetated geogrids consist of layers of live branch
cuttings and compacted soil with natural or synthetic
geotextile materials wrapped around each soil layer
(Figure 7.31). This serves to rebuild and vegetate eroded
Streambanks, particularly on outside bends where erosion
can be a problem. This system is designed to capture
sediment providing a substrate for plant establishment and
if properly designed and installed, these systems help to
quickly establish riparian vegetation. Its benefits are
similar to those of brush layering (e.g., dries excessively
wet sites, reinforces soil as roots develop, which adds
significant resistance to sliding or shear displacement).
Due to the strength of this design and the higher initial
tolerance to flow velocity, these systems can be installed
on a 1:1 or steeper streambank or lakeshore. Limitations
of this design include the complexity involved with
constructing this system and the fairly high expense (FISRWG, 1998). When constructing this
type of system, use live branch cuttings that are brushy and root readily. Also use cuttings that
are 0.5 to 2 inches in diameter and 4 to 6 feet long. This type of system requires biodegradable
erosion control fabric. Installation guidelines are available from the USDA-FS Soil
Bioengineering Guide (USDA-FS, 2002).
Additional Resources
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
> Massachusetts DEP. 2006. Massachusetts Nonpoint Source Pollution Management Manual:
Vegetated Geogrids. Massachusetts Department of Environmental Protection, Boston, MA.
http://proiects.geosyntec.corri/NPSManual/Fact%20SheetsA^egetated%20Geogrids.pdf.
> ISU. 2006. How to Control Streambank Erosion: Vegetated Geogrids. Iowa State University.
http://www.ctre.iastate.edu/erosion/manuals/streambank/vegetated_geogrids.pdf.
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Vegetated Geogrids. Created for United States
Department of Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/vegegeogrids.pdf.
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Chapter 7: Practices for Implementing Management Measures
VEGETATED GEOGRID
Geotextile
Fabric
Dead Stout Stakes:
secure geotextile
- fabric
Eroded Streambank
Compacted Soil layer
Approximately 1' Thick
Live Branch Cuttings
• 4' - 6!
Note: Rooted or leafed
condition of piant material is
not representative of its
condition at installation.
Figure 7.31 Vegetated Geogrid (USDA-FS, 2002)
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
D Structural
0 Integrated
D Planning & regulatory
Vegetated Reinforced Soil Slope (VRSS)
The vegetated reinforced soil slope (VRSS) soil system
(Figures 7.32 and 7.33) is an earthen structure constructed
from living, rootable, live-cut, woody plant material
branches, bare root, tubling or container plant stock, along
with rock, geosynthetics, geogrids, and/or geocomposites.
The VRSS system is useful for immediately repairing or
preventing deeper failures, providing a structurally sound
system with soil reinforcement, drainage, and erosion
control (typically on steepened slope sites with limited
space). Living cut branches and plants grow and perform
additional soil reinforcement via the roots and surface
protection via the top growth (Sotir and Fischenich, 2003).
Live vegetation is typically installed from just above
baseflow elevation and up the face of the reconstructed
streambank, acting to protect the bank through immediate
soil reinforcement and confinement, drainage, and, in the toe
area, with rock. The system extends below the depth of
scour, typically with rock, which improves infiltration and
supports the riparian zone. Internal systems (e.g., rock, live
cut branches) can be configured to act as drains that redirect
or collect internal bank seepage and transport water to the
stream via a rock toe (Sotir and Fischenich, 2003).
Plants may be selected to provide color, texture, and other
attributes to add a natural landscape appearance. Examples
of plants include dogwood, willow, hybiscus, and Viburnum
spp. Check with your local NRCS office to make sure these
are appropriate for the location. If a compound channel cross
section is desirable near or just below the baseflow
elevation, a step-back terrace may be incorporated to offer
an enhanced riparian zone where emergent aquatic plants
may invade over time. Although the total mass uptake may
be small, they assimilate contaminants within the water
column. Aquatic wetland plants that may be installed
adjacent to the stream include blueflag, monkey flower, and
pickerelweed. Again, check with your local NRCS office to
ensure these are appropriate. VRSS systems can be constructed on slopes ranging from IV on 2H
(1:2) to 1:0.5. When constructed in step or terrace fashion, they improve pollutant control by
intercepting sediment and attached pollutants during overbank flows (Sotir and Fischenich,
2003). Additional information about VRSS systems is available from USACE's Vegetated
Reinforced Soil Slope Streambank Erosion Control.14
Figure 7.32 VRSS Structure After
Construction
(Sotir and Fischenich, 2003)
Figure 7.33 Established VRSS
Structure (Sotir and Fischenich, 2003)
14
http://el.erdc.usace.army.mil/elpubs/pdf/sr30.pdf
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Chapter 7: Practices for Implementing Management Measures
Water Conveyances
These are the open or closed channel, conduit, or drop
structure used to convey water from a reservoir. The
USAGE has studied the performance of spillways and
overflow weirs at its facilities to determine the importance
of these structures in improving DO levels. For example,
data have been analyzed for the test spill done in 1999 at
Canyon Ferry Dam in Montana, which found that allowing
a portion of the releases to go over the spillways resulted in
a significant increase in DO in the river downstream of the
dam. Initially the use of spillways appeared to be a viable
solution to the problem of low dissolved oxygen in the
river below the dam. However, there was a problem with
nitrogen supersaturation.
The operation of some types of hydraulic structures has
been linked to problems of the supersaturation. An
unexpected fish kill occurred in spring 1978 due to supersaturation of nitrogen gas in the Lake of
the Ozarks (Missouri) within 5 miles of Truman Dam, caused by water plunging over the
spillway and entraining air. The vertical drop between the spillway crest and the tailwaters was
only 5 feet. The maximum total gas saturation was 143 percent, which is well above desired
saturation levels. In this case, the spillway was modified by cutting a notch to prevent water from
plunging directly into the stilling basin (ASCE, 1986).
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
0 Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Wildflower Cover
Because of the hardy, drought-resistant nature of
wildflowers, they may be more beneficial as an erosion
control practice than turf grass. Though not as dense as
turfgrass, wildflower thatches and associated grasses are
expected to be as effective in erosion control and
contaminant absorption. An additional benefit of
wildflower thatches is that they provide habitat for
wildlife, including insects and small mammals. Because
thatches of wildflowers do not need fertilizers, pesticides,
or herbicides and watering is minimal, implementation of
this practice may result in cost savings.
A wildflower stand requires several years to become
established, but maintenance requirements are minimal
once established. Prices vary greatly, from less than $15
(Stock Seed Farms, n.d.) to $40 (Albright Seed Company,
2002) a pound, for wildflower seed mixes. The amount of wildflower seeds applied depends on
the desired coverage of wildflowers. However, Stock Seed Farms recommends that one pound of
seed can cover 3,500 ft2 (Stock Seed Farms, n.d.). Keep in mind that species selection should
focus on those wildflowers and grasses native to the given area or appropriate to the site.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Wind Erosion Controls
Wind erosion controls limit the movement of dust from
disturbed soil surfaces and include many different
practices. Wind barriers block air currents and are effective
in controlling soil blowing. Many different materials can
be used as wind barriers, including solid board fences,
snow fences, and bales of hay. Sprinkling moistens the soil
surface with water and must be repeated as needed to be
effective for preventing wind erosion (Delaware DNREC,
2003); however, applications must be monitored to prevent
excessive runoff and erosion.
Channelization
D Physical & chemical
D Instream/riparian restoration
Dams
0 Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
D Streambanks D Shorelines
D Vegetative
D Structural
D Integrated
D Planning & regulatory
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Chapter 7: Practices for Implementing Management Measures
Channelization
0 Physical & chemical
0 Instream/riparian restoration
Dams
D Erosion control
D Runoff control
D Chemical/pollutant control
D Watershed protection
D Aerate reservoir water
D Improve tailwater oxygen
D Restore/maintain habitat
D Maintain fish passage
Erosion
0 Streambanks 0 Shorelines
D Vegetative
0 Structural
D Integrated
D Planning & regulatory
Wing Deflectors
Wing deflectors are structures that protrude from either
streambank but do not extend entirely across a channel.
The structures are designed to deflect flows away from the
bank, and create scour pools by constricting the channel
and accelerating flow. The structures can be installed in
series on alternative streambanks to produce a meandering
thalweg and stream diversity. The most common design is
a rock and rock-filled log crib deflector structure. The
design bases the size of the structure on anticipated scour.
These structures need to be installed far enough
downstream from riffle areas to avoid backwater effects
that could drown out or damage the riffle. This design
should be employed in streams with low physical habitat
diversity, particularly channels that lack pool habitats.
Construction on a sand bed stream may be susceptible to
failure and should be constructed with the use a filter layer
or geotextile fabric beneath the wing deflector structure (FISRWG, 1998).
Additional Resources
^ FISRWG. 1998. Stream Corridor Restoration: Principles, Processes, and Practices. Federal
Interagency Stream Restoration Working Group.
http://www.nrcs.usda.gov/technical/stream restoration/PDFFILES/APPENDIX.pdf.
^ Massachusetts DEP. 2006. Massachusetts Nonpoint Source Pollution Management Manual:
Wing Deflectors. Massachusetts Department of Environmental Protection, Boston, MA.
http://projects.geosyntec.corri/NPSManual/Fact%20SheetsAVing%20Deflectors.pdf.
> Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Single Wing Deflector. Created for United States
Department of Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://www.abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/singlewing.pdf.
^ Mississippi State University, Center for Sustainable Design. 1999. Water Related Best
Management Practices in the Landscape: Double Wing Deflector. Created for United States
Department of Agriculture, Natural Resource Conservation Service, Watershed Science Institute.
http://abe.msstate.edu/csd/NRCS-BMPs/pdf/streams/bank/doublewing.pdf.
^ Ohio DNR. No date. Ohio Stream Management Guide: Deflectors. Ohio Department of Natural
Resources, http://www.ohiodnr.com/water/pubs/fs st/stfs 19.pdf.
> SMRC. No date. Stream Restoration: Flow Deflection/Concentration Practices. The Stormwater
Manager's Resource Center.
http://www.stormwatercenter.net/Assorted%20Fact%20Sheets/Restoration/flow deflection.htm.
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Chapter 8: Modeling Information
Chapter 8: Modeling Information
Physical and chemical effects of hydraulic and hydrologic changes to streams, rivers, or other
surface water systems can often be estimated with models and past experience (expert judgment).
Several different models are available that can simulate many of the complex physical, chemical,
and biological interactions that occur when hydraulic changes are imposed on surface water
systems. Additionally, models can sometimes be used to determine a combination of practices to
mitigate the unavoidable effects that occur even when a project is properly planned. Models,
however, cannot be used independently of expert judgment gained through past experience.
When properly applied models are used in conjunction with expert judgment, the effects of
hydromodification activities (both potential and existing projects) can be evaluated and many
undesirable effects prevented or eliminated. Models combined with expert judgment can also be
used to evaluate existing hydromodification activities as part of operation and maintenance
programs to identify possible opportunities to reduce or eliminate water quality impacts.
In the U.S. Army Corps of Engineers' (US ACE's) report, Review of Watershed Water Quality
Models1 (Deliman et al., 1999), the authors compare and evaluate existing hydrologic and
watershed water quality models, make recommendations for base model(s) for predicting
nonpoint source (NFS) pollution, and identify areas for model improvement. The authors review
commonly used and well validated models used in urban or nonurban settings. Users of the
models can use the report to obtain basic model information and to review how well the models
simulate NFS pollution and where the authors think improvements could be made. This
information might be useful to readers who are trying to select the best model for analyzing how
to reduce NFS pollution in their watersheds (Deliman et al., 1999).
Tables 8.1 and 8.2 below provided example of models and assessment approaches that could be
used to determine the effects of hydromodification activities.
http://el.erdc.usace.army.mil/elpubs/pdf/trw99-l.pdf
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Available Models and Assessment Approaches
Table 8.1 lists some of the models available for studying the effects of channelization and channel modification activities, as well as
models to analyze watershed runoff and to assess BMPs and low impact development to reduce impacts (of hydromodification
activities.) The table also provides a quick description of each model and the dimension in which it models, as well as source and
contact information.
Table 8.1 Models Applicable to Hydromodification Activities
Model
Dimension
Description
Model Resources
Channelization and Channel Modification Models
BRANCH
The Branch-Network Dynamic Flow Model is used to simulate
steady state flow in a single open channel reach or
throughout a system of branches connected in a dendritic or
looped pattern. The model is typically applied to assess flow
and transport in upland rivers where flows are highly
regulated or backwater effects are evident, or in coastal
networks of open channels where flow and transport are
governed by the interaction of freshwater inflows, tidal action,
and meteorological conditions. (Last updated: 1997)
http://water.usgs.gov/cgi-bin/
man wrdapp?branch
CE-QUAL-RIV1
CE-QUAL-RIV1 is a one-dimensional (cross-sectionally
averaged) hydrodynamic and water quality model, meaning
that the model resolves longitudinal variations in hydraulic
and quality characteristics and is applicable where lateral and
vertical variations are small. CE-QUAL-RIV1 consists of two
parts, a hydrodynamic code (RIV1H) and a water quality code
(RIV1Q). The hydrodynamic code is applied first to predict
water transport and its results are written to a file, which is
then read by the quality model. It can be used to predict one-
dimensional hydraulic and water quality variations in streams
and rivers with highly unsteady flows, although it can also be
used for prediction under steady flow conditions.
http://www.wes.army.mil/el/elmodels/
riv1info.html
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Model
Dimension
Description
Model Resources
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CE-QUAL-W2
CE-QUAL-W2 is a two-dimensional, laterally averaged, finite
difference hydrodynamic and water quality model for rivers,
reservoirs, and estuaries. Because the model assumes lateral
homogeneity, it is best suited for relatively long and narrow
waterbodies exhibiting longitudinal and vertical water quality
gradients. Branched networks can be modeled. The model
accommodates variable grid spacing (segment lengths and
layer thicknesses) so that greater resolution in the grid can be
specified where needed.
http://smiq.usqs.qov/cqi-bin/SMIC/model
home pages/model home?selection=cequalw2
http://www.ce.pdx.edu/w2
CH3D-SED
1,2, or 3
The CH3D numerical modeling system can be used to
investigate sedimentation on bendways, crossings, and
distributaries. Applications address dredging, channel
evolution, and channel training structure evaluations.
http://chl.erdc.usace.army.mil/
chl.aspx?p=s&a=Software:22
EFDC
1,2, or 3
The Environmental Fluid Dynamics Code is a single source,
three-dimensional, finite-difference modeling system having
hydrodynamic, water quality-eutrophication, sediment
transport and toxic contaminant transport components linked
together.
John Hamrick developed this at the Virginia
Institute of Marine Science 1990-1991. Dr.
John Hamrick, Tetra Tech, Inc. 10306 Eaton
Place, Suite 340 Fairfax, VA 22030
EFM
Ecosystem Functions Model (EFM) is a planning tool that
analyzes ecosystem response to changes in flow regime.
EFM allows environmental planners, biologists, and engineers
to determine whether proposed alternatives (e.g., reservoir
operations, levee alignments) would maintain, enhance, or
diminish ecosystem health. Project teams can use EFM
software to visualize existing ecologic conditions, highlight
promising restoration sites, and assess and rank alternatives
according to the relative enhancement (or decline) of
ecosystem aspects. The hydraulic modeling portion of the
EFM process is performed by existing independent software,
such as HEC-RAS.
http://el.erdc.usace.armv.mil/elpubs/pdf/
smartnote04-4.pdf
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Model
Dimension
Description
Model Resources
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FESWMS-2DH
FESWMS-2DH is a finite element surface water modeling
system for two-dimensional flow in a horizontal plane. The
model can simulate steady and unsteady surface water flow
and is useful for simulating two-dimensional flow where
complicated hydraulic conditions exist (e.g., highway
crossings of streams and flood rivers). It can also be applied
to many types of steady or unsteady flow problems. (Last
updated: 1995)
http://water.usgs.gov/cgi-
bin/man wrdapp?feswms-2dh
HEC-6
HEC-6 is a one-dimensional, moveable boundary, open
channel flow numeric model designed to simulate and predict
changes in river profiles resulting from scour and deposition
over moderate time periods, typically years. Latest revision
occurred in 1993.
http://www.hec.usace.armv.mil/software/legacys
oftware/hec6/hec6.htm
HEC-HMS
The HEC-HMS model is designed to simulate the precipitation-
runoff processes of dendritic watershed systems. It is
applicable in a wide range of geographic areas for solving the
widest possible range of problems, including large river basin
water supply and flood hydrology, and small urban or natural
watershed runoff. Hydrographs produced by the program are
used directly or in conjunction with other software for studies of
water availability, urban drainage, flow forecasting, future
urbanization impact, reservoir spillway design, flood damage
reduction, floodplain regulation, and systems operation.
http://www.hec.usace.army.mil/software/
hec-hms/index.html
http://el.erdc.usace.army.mil/elpubs/pdf/
smartnote04-3.pdf
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Model
Dimension
Description
Model Resources
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HEC-RAS
HEC-RAS is an integrated system of software, designed for
interactive use in a multi-tasking, multi-user network
environment. The system is comprised of a graphical interface
(GUI), separate hydraulic analysis components, data storage
and management capabilities, graphics and reporting facilities.
The model performs one-dimensional steady flow, unsteady
flow, and sediment transport calculations. The key element is
that all three components will use a common geometric data
representation and common geometric and hydraulic
computation routines. In addition to the three hydraulic
analysis components, the system contains several hydraulic
design features that can be invoked once basic water surface
profiles are computed. The HEC-RAS modeling system was
developed as a part of the Hydrologic Engineering Center's
"Next Generation" (NexGen) of hydrologic engineering
software. The NexGen project encompasses several aspects
of hydrologic engineering, including: rainfall-runoff analysis;
river hydraulics; reservoir system simulation; flood damage
analysis; and real-time river forecasting for reservoir
operations.
http://www.hec.usace.army.mil/software/hec-ras
HIVEL2D
1,2
HIVEL2D is a free-surface, depth averaged model designed
specifically to simulate flow in typical high-velocity channels.
http://chl.erdc.usace.army.mil/CHL.aspx?p=s&
a=Software:6
RiverWare™
RiverWare™ is a reservoir and river modeling software
decision support tool. With RiverWare™, users can model the
topology, physical processes and operating policies of river
and reservoir systems, and make better decisions about how
to operate these systems by understanding and evaluating
the trade-offs among the various management objectives.
Water management professionals can improve their
management of river and reservoir systems by using the
software. The Bureau of Reclamation, the Tennessee Valley
Authority, and the USAGE sponsor ongoing RiverWare™
research and development.
http://cadswes.colorado.edu/riverware
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Dimension
Description
Model Resources
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SAM
The model calculates the width, depth, slope and n-values for
stable channels in alluvial material. SAM can be used to
evaluate erosion, entrainment, transportation, and deposition
in alluvial streams. Channel stability can be evaluated, and
the evaluation used to determine the cost of maintaining a
constructed project. The model is currently being improved
and enhanced at WES.
http://chl.erdc.usace.army.mil/
CHL.aspx?p=s&a=Software:2
SIAM
N/A
SIAM is a model designed to simulate the movement of
sediment through a drainage network from source to outlet. It
allows for evaluation of numerous sediment management
alternatives relatively quickly. The model provides an
intermediate level of analysis more quantitative than a
conventional geomorphic evaluation, but less specific than a
numerical, mobile-boundary simulation. SIAM is to be
incorporated into a future release of HEC-RAS.
http://www.usbr.gov/pmts/sediment/model/
srhsiam/index.html
http://www.wes.army.mil/rsm/pubs/pdfs/
RSM-2-WS04.pdf
SMS
(RMA2 and RMA4)
1,2
The Surface-Water Modeling System is a generalized
numerical modeling system for open-channel flows,
sedimentation, and constituent transport.
http://chl.erdc.usace.army.mil/CHL.aspx?p=s&a
=Software:4
TABS-MD
(RMA2, RMA4,
RMA10, SED2D)
1,2, or 3
The multi-dimensional numerical modeling system is a
collection of generalized computer programs and utility codes,
designed for studying multidimensional hydrodynamics in
rivers, reservoirs, bays, and estuaries. The models can be
applied to study project impacts of flows, sedimentation,
constituent transport, and salinity.
http://chl.erdc.usace.army.mil/CHL.aspx?p=s&a
=Software:10
WASP
1,2, or 3
Water Quality Analysis Simulation Program. Framework for
modeling contaminant fate and transport in surface waters.
The WASP framework can be used to model biochemical
oxygen demand and dissolved oxygen dynamics, nutrients and
eutrophication, bacterial contamination, and organic chemical
and heavy metal contamination.
http://www.epa.qov/athens/wwqtsc/html/
wasp.html
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Dimension
Description
Model Resources
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Models to Analyze Watershed Runoff and Assess Practices to Reduce Impacts of Hydromodification
BMP Decision
Support System
(BMP-DSS)
1
BMP-DSS is a decision-making tool for placement of
BMPs/LID practices at strategic locations in urban watersheds
based on integrated data collection and
hydrologic/hydraulic/water quality modeling. The system uses
CIS technology, integrates BMP processes simulation
models, and applies system optimization techniques for BMP
placement and selection. The system also provides interfaces
for BMP placement, BMP attribute data input, and decision
optimization management. The system includes a stand-alone
BMP simulation and evaluation module, which complements
both research and regulatory nonpoint source control
assessment efforts and allows flexibility in examining various
BMP design alternatives.
Developed by the EPA and Prince George's
County Department of Environmental
Resources. Contact Dr. Mow-Soung Cheng at
301-883-5836 for more information.
HSPF
Hydrological Simulation Program—FORTRAN (HSPF) is a
comprehensive package for simulation of watershed
hydrology and water quality for both conventional and toxic
organic pollutants. HSPF incorporates watershed-scale ARM
and NPS models into a basin-scale analysis framework that
includes fate and transport in one dimensional stream
channels. It is the only comprehensive model of watershed
hydrology and water quality that allows the integrated
simulation of land and soil contaminant runoff processes with
In-stream hydraulic and sediment-chemical interactions. The
result of this simulation is a time history of the runoff flow rate,
sediment load, and nutrient and pesticide concentrations,
along with a time history of water quantity and quality at any
point in a watershed. HSPF simulates three sediment types
(sand, silt, and clay) in addition to a single organic chemical
and transformation products of that chemical.
http://www.epa.qov/ceampubl/swater/hspf/
index.htm
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Dimension
Description
Model Resources
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LSPC
LSPC is the Loading Simulation Program in C++, a watershed
modeling system that includes streamlined Hydrologic
Simulation Program Fortran (HSPF) algorithms for simulating
hydrology, sediment, and general water quality on land as
well as a simplified stream transport model. LSPC is derived
from the Mining Data Analysis System (MDAS), which was
developed by EPA Region 3 and has been widely used for
mining applications and TMDLs. A key data management
feature of this system is that it uses a Microsoft Access
database to manage model data and weather text files for
driving the simulation. The system also contains a module to
assist in TMDL calculation and source allocations. For each
model run, it automatically generates comprehensive text-file
output by subwatershed for all land-layers, reaches, and
simulated modules, which can be expressed on hourly or
daily intervals. Output from LSPC has been linked to other
model applications such as EFDC, WASP, and CE-QUAL-
W2.
http://www.epa.gov/ATHENS/wwqtsc/html/
lspc.html
Program for
Predicting
Polluting Particle
Passage through
Pits, Puddles,
and Ponds—
Urban Catchment
Model (P8-UCM)
P8-UCM is a model for predicting the generation and
transport of stormwater pollutants in urban watersheds.
Continuous water balance and mass balance calculations are
performed on a user-defined system consisting of
watersheds, devices (runoff storage/treatment areas, BMPs),
particle classes, and water quality components. Simulations
are driven by continuous hourly rainfall and daily air
temperature time series data. The model simulates pollutant
transport and removal in a variety of treatment devices
(BMPs).
http://wwwalker.net/p8
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Model
Dimension
Description
Model Resources
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Storm Water
Management
Model (SWMM)
SWMM is a dynamic rainfall-runoff simulation model used for
single event or long-term (continuous) simulation of runoff
quantity and quality from primarily urban areas. The runoff
component of SWMM operates on a collection of
subcatchment areas that receive precipitation and generate
runoff and pollutant loads. The routing portion of SWMM
transports this runoff through a system of pipes, channels,
storage/treatment devices, pumps, and regulators. SWMM
tracks the quantity and quality of runoff generated within each
subcatchment, and the flow rate, flow depth, and quality of
water in each pipe and channel during a simulation period
comprised of multiple time steps.
http://www.epa.qov/ednnrmrl/models/swmm/
index.htm
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Table 8.2 lists some of the available assessment models and approaches for assessing the biological impacts of channelization. The
table also provides a quick description of the model or approach, as well as sources of additional information.
Table 8.2 Assessment Models and Approaches
Model or
Assessment
Approach
Description
Model Resources
Assessment Models
AQUATOX
A freshwater ecosystem simulation model designed to
predict the fate of various pollutants such as nutrients
and organic toxicants and their effects on the
ecosystem, including fish, invertebrates, and aquatic
plants (including periphyton).
http://epa.gov/waterscience/models/aquatox
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Cornell Mixing Zone
Expert System
(CORMIX)
A water quality modeling and decision support system
designed for environmental impact assessment of
mixing zones resulting from wastewater discharge from
point sources. The system emphasizes the role of
boundary interaction to predict plume geometry and
dilution in relation to regulatory mixing zone
requirements.
http://www.epa.gov/waterscience/models/cormix.html
HEC-HMS,
Hydrologic Modeling
System
A system designed to simulate the precipitation-runoff
processes of dendritic watershed systems. In addition to
unit hydrograph and hydrologic routing options,
capabilities include a linear quasi-distributed runoff
transform (ModClark) for use with gridded precipitation,
continuous simulation with either a one-layer or more
complex five-layer soil moisture method, and a versatile
parameter estimation option.
http://www.hec.usace.army.mil/software/hec-hms/index.html
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HEC-RAS, River
Analysis System
The HEC-RAS system is used to calculate water surface
profiles for both steady and unsteady gradually varied
flow. The system can handle a full network of channels,
a dendritic system, or a single river reach.
http://www.hec.usace.armv.mil/software/hec-ras/hecras-
hecras.html
http://www.wsi.nrcs.usda.gov/products/W2Q/H&H/Tools
Models/Ras.html
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Model or
Assessment
Approach
Description
Model Resources
Physical Habitat
Simulation Model
(PHABSIM)
A set of computer programs designed to predict the
microhabitat (depth, velocities, channel indices)
conditions in rivers at different flow levels and the
relative suitability of those conditions for different life
stages of aquatic life. (Serves as the key microhabitat
simulation component of IFIM.)
http://www.fort.usgs.gov/Products/Software/PHABSIM
Riverine Community
Habitat Assessment
and Restoration
Concept (RCHARC)
A simulation approach using computer models to
compare hydraulic conditions and microhabitats of a
reference reach to alternative study reach(es).
Nestler, J., T. Schneider, and D. Latka. 1993. RCHARC: A
new method for physical habitat analysis. Engineering
Hydrology, 294-99.
RiverWare™
RiverWare™ is a reservoir and river modeling software
decision support tool. With RiverWare™, users can
model the topology, physical processes, and operating
policies of river and reservoir systems, and make better
decisions about how to operate these systems by
understanding and evaluating the trade-offs among the
various management objectives. Water management
professionals can improve their management of river
and reservoir systems by using the software. The
Bureau of Reclamation, the Tennessee Valley Authority,
and the Army Corps of Engineers sponsor ongoing
RiverWare™ research and development.
http://cadswes.colorado.edu/riverware
Salmonid Population
Model (SALMOD)
A computer model that simulates the dynamics
(spawning, growth, movement, and mortality) of
freshwater salmonid populations, both anadromous and
resident, under various habitat quality and capacities.
http://www.fort.usgs.gov/Products/Software/SALMOD
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Assessment Approaches
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A Procedure to
Estimate the
Response of Aquatic
Systems to Changes
in Phosphorus and
Nitrogen Inputs
A simple tool to estimate the responsiveness of a
waterbody to changes in the loading of phosphorus and
nitrogen using a dichotomous key that classifies it
according to key characteristics.
ftp://ftp.wcc.nrcs.usda.gov/downloads/wgam/agusens.pdf
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Model or
Assessment
Approach
Description
Model Resources
EPA Volunteer
Stream Monitoring
Methods
A series of methods geared for volunteer monitoring
programs offering simple to advanced techniques for
monitoring macroinvertebrates, habitat, water quality,
and physical conditions.
http://www.epa.gov/owow/monitoring/volunteer/stream
Habitat Evaluation
Procedures/Habitat
Suitability Index
(HEP/HSI)
HEP is an evaluation method that determines the
suitability of available habitat for select aquatic and
terrestrial wildlife species and measures the impact of
proposed land or water use changes on that habitat. HSI
is a measure of habitat suitability.
http://policy.fws.gov/870fw1 .html
http://www.fort.usgs.gov/Products/Software/HEP
http://www.fort.usgs.gov/Products/Software/HSI
Index of Biological
Integrity (IBI)
An aquatic ecosystem health index using measures of
total native fish species composition, indicator species
composition, pollutant intolerant and tolerant species
composition, and fish condition.
http://www.epa.gov/owow/wetlands/wgual/bio fact/facts.html
Indicators of
Hydrologic Alteration
(I HA)
A method for assessing the degree of hydrologic
alteration attributable to human impacts within an
ecosystem. The method takes daily stream flow values
and calculates indices relating to the five components of
flow regime critical for ecological processes: magnitude,
frequency, duration, timing, and rate of change of
hydrologic conditions.
http://www.nature.org/initiatives/freshwater/conservationtools
/artl 7004.html
Instream Flow
Incremental
Methodology (IFIM)
A river network analysis that incorporates fish habitat,
recreational opportunity, and woody vegetation
responses to alternative water management schemes.
Information is presented as a time series of flow and
habitat at select points within the network.
http://www.fort.usgs.gov/Products/Software/IFIM
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Invertebrate
Community Index
(ICI)
An invertebrate community health index using ten
structural and compositional invertebrate community
metrics including number of mayfly, caddisfly, and
dipteran taxa.
http://www.epa.state.oh.us/dsw/bioassess/BioCriteriaProtAg
Life.html
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Model or
Assessment
Approach
Description
Model Resources
http://www.epa.state.oh.us/dsw/bioassess/BioCriteriaProtAq
Life.html
(Modified) Index of
Weil-Being (IWB)
The IWB is a fish community health index using
measures offish species abundance and diversity
estimates. The modified index of well being factors out
13 pollutant tolerant species offish from certain
calculations to prevent false high readings on polluted
streams which have large populations of pollutant
tolerant fish.
Rapid Bioassessment
Protocols (RBP)
A set of protocols that offer cost-effective techniques of
varying complexity to characterize the biological integrity
of streams and rivers using the collection and analysis of
biological, physical, and chemical data. It focuses on
periphyton, benthic macroinvertebrates, and fish
assemblages, and on assessing the quality of the
physical habitat.
http://www.epa.qov/owow/monitorinq/rbp
Rapid Channel
Assessment (RCA)
A reference stream/integrated ranking approach to
evaluate the physical condition of a stream channel
based on channel geometry, percent channel-bank
scour, sediment size distribution and embeddedness,
large wood debris, and thalweg profiles.
CWP. 1998. Rapid Watershed Planning Handbook: A
Comprehensive Guide for Managing Urbanizing Watersheds.
Center for Watershed Protection, Ellicott City, MD.
For a copy contact: The Center for Watershed Protection,
8391 Main Street Ellicott City, MD 21043, email:
center@cwp.org.
Rapid Stream
Assessment
Technique (RSAT)
A reference stream/integrated ranking approach to
evaluate steam health based on chemical stability,
channel scouring/sediment deposition, physical instream
habitat, water quality, riparian habitat, and biological
indicators.
CWP. 1998. Rapid Watershed Planning Handbook: A
Comprehensive Guide for Managing Urbanizing Watersheds.
Center for Watershed Protection, Ellicott City, MD.
For a copy contact: The Center for Watershed Protection,
8391 Main Street Ellicott City, MD 21043, email:
center@cwp.org.
http://www.stormwatercenter.net
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Rosgen's Stream
Classification Method
A classification method that uses morphological stream
characteristics to organize streams into relatively
homogeneous stream types to predict stream behavior
and to apply interpretive information.
O
O
Reference: Rosgen, D. 1996. Applied River Morphology.
Wildland Hydrology, Pagosa Springs, CO.
For a copy contact: Wildland Hydrology Books, 1481 Stevens
Lake Road, Pagosa Springs, CO 81147.
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Model or
Assessment
Approach
Description
Model Resources
Stream
Network/Stream
Segment
Temperature Models
(SNTEMP/SSTEMP)
Developed to help predict the consequences of stream
manipulation on water temperatures, these computer
models simulate mean daily water temperatures for
streams and rivers from data describing the stream's
geometry, meteorology, and hydrology. SNTEMP is for a
stream network with multiple tributaries for multiple time
periods. SSTEMP is a scaled down version suitable for
single (to a few) reaches and single (to a few) time
periods.
http://www.fort.usgs.gov/Products/Software/SNTEMP
Stream Visual
Assessment Protocol
(SVAP)
A simple procedure to evaluate the condition of a stream
based on visual characteristics. It also identifies
opportunities to enhance biological value and conveys
information on how streams function.
ftp://ftp.wcc.nrcs.usda.gov/downloads/wgam/svapfnl.pdf
Systems Impact
Assessment Model
(SI AM)
An integrated set of models used to aid the evaluation of
water management alternatives, it address significant
interrelationships among selected physical (temperature,
microhabitat), chemical (dissolved oxygen, water
temperature), and biological variables (young-of-year
Chinook salmon production), and stream flow.
Developed for the Klamath River in northern California.
http://www.fort.usgs.gov/Products/Software/SIAM
Time-Series Library
(TSLIB)
A set of DOS-based computer programs to create
monthly or daily habitat time-series and habitat-duration
curves using the habitat-discharge relationship produced
by PHABSIM. (Can serve as the hydraulic component of
IFIM).
http://www.fort.usgs.gov/Products/Software/TSLIB
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TR-20, Computer
Program for Project
Formulation
Hydrology
A physically based watershed scale runoff event model
that computes direct runoff and develops hydrographs
resulting from any synthetic or natural rainstorm.
Developed hydrographs are routed through stream and
valley reaches as well as through reservoirs.
http://www.wsi.nrcs.usda.gov/products/W2Q/H&H/Tools
Models/WinTR20.html
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TR-55, Urban
Hydrology for Small
Watersheds
Simplified procedures to calculate storm runoff volume,
peak rate of discharge, hydrographs, and storage
volumes required forfloodwater reservoirs.
http://www.info.usda.gov/CED/ftp/CED/tr55.pdf
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Chapter 8: Modeling Information
Examples of Channel Modification Activities and Associated
Models/Practices
Modeling for Impoundments
A low-complexity option for modeling impoundments is to use simple models like the Bathtub
model to simulate the waterbody. Compared to more complex multi-dimensional models, which
use multiple computational cells to estimate volumetric and contaminant fluxes between the
cells, Bathtub-type models typically use a single cell. This single cell, while a simplification of
the system, may be appropriate if the system is fully mixed in both the horizontal and vertical
dimensions. This approach can also be economically developed using spreadsheets (such as
Excel) to calculate the results. However, a Bathtub-type model has limited utility if the water
body is stratified or if results are required at more than one location in the system.
Another example of a modeling tool that has the ability to simulate impoundments is CE-QUAL-
W2, a two-dimensional hydrodynamic water quality model. CE-QUAL-W2 provides results for
either a horizontal or cross-sectional, two-dimensional plane. Because the model assumes a
vertically or horizontally-mixed environment, it is best suited for relatively long and narrow
water bodies (rivers, lakes, reservoirs, and estuaries) that exhibit longitudinal or vertical water
quality stratification. The water quality portion of CE-QUAL-W2 includes the major processes
of eutrophication kinetics and a single algal compartment. The bottom sediment compartment
stores settled particles, releases nutrients to the water column, and exerts sediment oxygen
demand based on user-supplied fluxes; a full sediment diagenesis (i.e., the process of chemical
and physical change in deposited sediment during its conversion to rock) model is under
development.
The Environmental Fluid Dynamics Code (EFDC) is a general-purpose modeling package for
simulating one- or multi-dimensional flow, transport, and bio-geochemical processes in surface
water systems including rivers, lakes, estuaries, reservoirs, wetlands, and coastal regions. The
EFDC model was originally developed by Hamrick in 1992 at the Virginia Institute of Marine
Science for estuarine and coastal applications and is considered public domain software. This
model is now EPA-supported as a component of EPA Region 2's PRVI BASINS software
system and EPA's TMDL Toolbox,2 and has been used extensively to support TMDL
development throughout the country. In addition to hydrodynamic, salinity, and temperature
transport simulation capabilities, EFDC is capable of simulating cohesive and non-cohesive
sediment transport, near field and far field discharge dilution from multiple sources,
eutrophi cation processes, the transport and fate of toxic contaminants in the water and sediment
phases, and the transport and fate of various life stages of finfish and shellfish.
Modeling for Estuary Tidal Flow Restrictions
Artificial hydraulic structures have the ability to alter natural flow patterns (hydrodynamic) in an
estuary, which may modify erosion patterns, salinity regimes, and the fate and transport of
pollutants. Some examples of artificial hydraulic structures include culverts, bridges, tide gates,
2 http://www.epa.gov/athens/wwqtsc/html/efdc.html
EPA841-B-07-002 8-15 July 2007
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Chapter 8: Modeling Information
and weir structures. Installation or removal of these structures may cause a significant change in
local hydrodynamics, and tools may be used to estimate the impacts prior to the modification.
The EFDC model, as described above, allows modelers to evaluate the impacts of hydraulic
structures, such as culverts, bridges, tide gates, and weirs. Due to the flexibility of EFDC, each of
these structures can also be conceptually represented in a variety of ways. For example, the weir
equation can be applied to locations in the modeling grid to estimate water surface-dependent
flow through one or more grid cells. This enables a modeler to evaluate the effect of placement
of structures that modify surface flow patterns (such as a weir). Structures such as piers and
impermeable barriers (e.g. jetties, breakwaters) can also be simulated using this code.
Another modeling tool that can address estuary tidal flow restrictions is the Finite Element
Surface Water Modeling System (FESWMS) model. This modeling code was developed by the
Federal Highway Administration (FHA) and is distributed by the U.S Geological Survey
(USGS). FESWMS is a hydrodynamic modeling code that simulates two-dimensional, depth-
integrated, steady or unsteady surface-water flows. It supports both super and subcritical flow
analysis, and area wetting and drying. FESWMS is also suited for modeling regions involving
flow control structures, such as are encountered at the intersection of roadways and waterways.
Specifically, the FESWMS model allows the user to include weirs, culverts, drop inlets, and
bridge piers into a standard two-dimensional finite element model. FESWMS does not have
three-dimensional capabilities.
Modeling for Estuary Flow Regime Alterations
A number of structures or processes can alter the flow regime of a system. Flow contributions to
an estuary can be altered by upstream rediversions or basin transfers, dams and dam releases, or
other channel modifications. For example, when freshwater flows patterns are altered by the
presence and operation of a dam, EFDC can be used to model the impact to downstream
estuaries. EFDC can provide modelers with a time series representation of flow that is withdrawn
from a simulated reservoir/dam system. Coupling the time series flow projections with
hydrodynamic analysis of the receiving esturay enables modelers to determine potential impacts
of altered flow patterms and to evaluate various spill options for the dam operation. Structures
within the estuary that may alter the flow patterns include marinas, piers, jetties, and other
similar type structures. Flow regime alterations due to these structures can be simulated using the
same modeling tools described in the Flow Restrictions section above. Flow restrictions are the
cause of most changes in the flow regime, so the simulation of the causes of restriction using a
process-based modeling tool produces the desired flow alterations. Therefore, EFDC and
FESWMS can be utilized in the same manner to obtain flow regime results.
Temperature Restoration Practices
Several computer models that predict instream water temperature are currently available. These
models vary in the complexity of detail with which site characteristics, including meteorology,
hydrology, stream geometry, and riparian vegetation, are described. The U.S. Fish and Wildlife
Service developed an instream surface water temperature model (Theurer et al., 1984) to predict
mean daily temperature and diurnal fluctuations in surface water temperatures throughout a
stream system. The model, Stream Network Temperature Model (SNTEMP), can be applied to
any size watershed or river system. This predictive model uses either historical or synthetic
EPA841-B-07-002 8-16 July 2007
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Chapter 8: Modeling Information
hydrological, meteorological, and stream geometry characteristics to describe the ambient
conditions. The purpose of the model is to predict the longitudinal temperature and its temporal
variations. The instream surface water temperature model has been used satisfactorily to evaluate
the impacts of riparian vegetation, reservoir releases, and stream withdrawal and returns on
surface water temperature. In the Upper Colorado River Basin, the model was used to study the
impact of temperature on endangered species (Theurer et al., 1982). It also has been used in
smaller ungauged watersheds to study the impacts of riparian vegetation on salmonid habitat.3
The Stream Segment Temperature Model (SSTEMP) is a much-scaled down version of the
SNTEMP model developed by the USGS Biological Resource Division. Unlike the large
network model (SNTEMP), this program only handles single stream segments for a single time
period (e.g., month, week, day) for any given "run." Initially designed as a training tool,
SSTEMP may be used satisfactorily for a variety of simple cases that one might face on a day-to-
day basis. It is especially useful to perform sensitivity and uncertainty analysis. The model
predicts minimum 24-hour temperatures, mean 24-hour temperatures, and maximum 24-hour
stream temperatures for a given day, as well as a variety of intermediate values. The SSTEMP
model identifies current stream and/or watershed characteristics that control stream temperatures.
The model also quantifies the maximum loading capacity of the stream to meet water quality
standards for temperature. This model is important for estimating the effect of changing controls
or factors (such as riparian grazing, stream channel alteration, and reduced streamflow) on
stream temperature. The model can also be used to help identify possible implementation
activities to improve stream temperature by targeting those factors causing impairment to the
stream. Good input data and an awareness of the model's assumptions are critical to obtaining
reliable predictions. SSTEMP may be used to evaluate alternative reservoir release proposals,
analyze the effects of changing riparian shade or the physical features of a stream, and examine
the effects of different withdrawals and returns on instream temperature.4
Selecting Appropriate Models
Although a wide range of adequate hydrodynamic and surface water quality models are
available, the central issue in selecting appropriate models for evaluating hydromodification
projects is the appropriate match of the financial and geographical scale of the proposed project
with the cost required to perform a credible technical evaluation of the projected environmental
impact. It is highly unlikely, for example, that a proposal for a relatively small stream channel
modification project, such as installing culverts in a stream segment, would be expected or
required to contain a state-of-the-art hydrodynamic and surface water quality analysis that
requires one or more person-years of effort. In such projects, a simplified, desktop approach
(e.g., HEC-RAS Model) requiring less time and money would most likely be sufficient (USAGE,
2002a). In contrast, substantial technical assessment of the long-term environmental impacts
would be expected for channelization proposed as part of construction of a major harbor facility
or as part of a system of navigation and flood control locks and dams. The assessment should
3 For more information or to download SNTEMP, see the U.S. Geological Survey Web site:
http://www.fort.usgs.gov/Products/Software/SNTEMP.
4 More information about the model is available on the U.S. Geological Survey Web site:
http://www.mesc.usgs.gov/products/software/default.asp (navigate to Stream Network Temperature Model and
Stream Segment Temperature Model).
EPA841-B-07-002 8-17 July 2007
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Chapter 8: Modeling Information
incorporate the use of detailed 2D or 3D hydrodynamic models coupled with sediment transport
and surface water quality models.
In general, six criteria can be used to review available models for potential application in a given
hydromodification project:
1. Time and resources available for model application
2. Ease of application
3. Availability of documentation
4. Applicability of modeled processes and constituents to project objectives and concerns
5. Hydrodynamic modeling capabilities
6. Demonstrated applicability to size and type of project
The Center for Exposure Assessment Modeling (CEAM),5 EPA Environmental Research
Laboratory, Athens, Georgia, provides continual support for several hydrodynamic and surface
water quality models, such as HSCTM2D, HSPF, PRZM3, and SED3D. Another source of
information and technical support is the Waterways Experiment Station, USAGE, Vicksburg,
Mississippi.6 Although a number of available models are in the public domain, costs associated
with setting up and operating these models may exceed the project's available resources. For a
simple to moderately difficult application, the approximate level of effort varies, but could range
from 1 to 12 person-months.
Several factors need to be considered in the application of mathematical models to predict
impacts from hydromodification projects including:
• Variations and uncertainties in the accuracy of these models when they are applied to the
short- and long-term response of natural systems.
• Availability of relevant information (data collection) to derive the simulations and
validate the modeling results.
The cost of a given modeling project depends on a number of factors. Questions need to be asked
prior to the start of a modeling project to determine the purpose and future use of the model,
and/or its results. For example, the modeler needs to know if the model results are to be used
deterministically (the model assumes there is only one possible result that is known for each
alternative course or action), or if the model is to be used for a heuristic (involving or serving as
an aid to learning, discovery, or problem-solving by experimental and especially trial-and-error
methods) scoping exercise to identify data gaps in a system. In a deterministic study, the results
are traditionally compared to observed data in an effort regarded as calibration and validation.
The model must therefore be rigorous enough to represent the system accurately. The complexity
of the system under study is also a consideration that must be made prior to the project. The
complexity of the system generally correlates well with the level of complexity of the model
required to simulate it. Likewise, the more complex the model is, the more intensive it is to
develop and run, and the more costly the modeling project is.
5 http://www.epa.gov/ceampubl
6 http://www.erdc.usace.army.mil
EPA841-B-07-002 8-18 July 2007
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Chapter 8: Modeling Information
A number of approaches are available to model a given system, and the discussion above only
highlights a few of the modeling tools currently available. The cost to set up a model for a given
system varies tremendously, based not only on the modeling code selected, but also on what the
modeler decides to simulate. For example, a modeler may aim to obtain flow results for an
estuary using a given model. In reality, surface winds in that estuary may or may not be
influencing the flow regime. If observed wind data is available from a weather station nearby,
the modeler may choose to incorporate these data into the model to better represent that
influence. The modeler may also choose not to incorporate these data, or the data may not be
available. Although the modeler is utilizing the same modeling code, the decision regarding
whether or not to simulate the wind conditions is not only a question regarding the model's
purpose, but also what the development of this model will cost.
Modeling tools can range from simple spreadsheet tools using "back of the envelope" type
calculations, to complex processed based models that must be run on high performance
computing systems. As discussed previously, the tool selected for a given modeling project
needs to be chosen with a number of questions in mind. As a result, each system can be modeled
in a number of different ways with a number of different modeling codes. Therefore, the range in
cost for even a single estuary or impoundment may range tenfold depending on the model's
purpose. Typically, the cost of developing a model may range from a few thousand dollars for a
simple spreadsheet model, to in excess of one million dollars for a more robust modeling system.
EPA841-B-07-002 8-19 July 2007
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Chapter 9: Dam Removal Requirements, Process, and Techniques
Chapter 9: Dam Removal Requirements, Process, and Techniques
Chapter 2 provided a discussion of specific impacts from dams, water quality above and below
the dam, suspended sediment and recharge issues, and biological and habitat impacts. Chapter 4
then provided a discussion of types of dams, Federal Energy Regulatory Commission (FERC)
requirements, management measures and practices that can be used to mitigate for some of the
effects of dams, and information to consider when contemplating removing a dam. Chapter 9
focuses on what occurs after the decision has been made to remove a dam. This chapter provides
a more detailed discussion on some permitting requirements for removing dams, the dam
removal process, and sediment removal techniques to consider when removing a dam.
Requirements for Removing Dams
Removing a dam may require evaluations and permits from state, federal, and local authorities.
These requirements are typically to ensure that the removal is done is a manner that is safe and
minimizes short and long term impacts to the river and floodplain. States and local governments
have different requirements. The following federal requirements may apply to dam removal:
• Rivers and Harbors Act Permit
• FERC License Surrender or Non-power License Approval
• National Environmental Policy Act (NEPA) Review
• Federal Consultations (Endangered Species Act Section 7 Consultation, Magnuson-
Stevenson Act Consultation, National Historic Preservation Act Compliance)
• State Certifications (Water Quality Certification, Coastal Zone Management Act
Certification)
The following state requirements might apply to dam removal:
• Clean Water Act (CWA) Section 404 Dredge and Fill Permit
• Waterway Development Permits
• Dam Safety Permits
• State Environmental Policy Act Review
• Historic Preservation Review
• Resetting the Floodplain
• State Certifications
Demolition and building permits may also be required for dam removal. Individual state and
local governments may have additional requirements as well.
EPA841-B-07-002 9-1 July 2007
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Chapter 9: Dam Removal Requirements, Process, and Techniques
Tips for a Successful Permitting Process (American Rivers, 2002b)
Dam removal is relatively new and the permitting process can be difficult. Most state and federal
agencies are not yet practiced at moving dam removal through the permitting process. The relevant
permitting requirements were designed for more destructive activities, and dam removal does not
easily fit into the requirements. Tips to help make the process smoother include:
Schedule Time
• Expect dam removal projects to take longer than construction efforts.
• Schedule more lead-time into the permitting process to avoid delays and frustrations.
Establish a Relationship with the Permitting Agencies
• Hold a pre-application meeting with key agency staff once your project is well thought out.
• Do not attempt to circumvent the process and stick with the permitting timeline.
• Do not provide inconsistent information.
• A single point of contact for the group applying for the permit will help avoid confusion and
maintain communication.
Providing Information about the Proposed Project
• Create clear and simple descriptions and drawings (to scale) of the proposed project.
• Be sure to identify complicating conditions, schedules, seasonal constraints, etc.
• Provide and discuss alternatives, but make it clear why the chosen approach should be used.
• Assume the reviewers know nothing about your project.
Dam Removal Process
The complexity of the removal process of a dam is specific to each particular case of removal.
There are two major components of the removal process: the stakeholders involved in the
decision-making process of removing the dam and the actual physical removal of the dam itself.
The authorities that govern dams are numerous, yet overlapping. These entities include: USAGE,
Bureau of Reclamation, FERC, and other federal agencies; interest groups; and state and local
governments. There are also various state programs that have been created to keep dams safe and
environmentally friendly, as well as to help owners finance dam removal. A study by the Aspen
Institute (2002) provides a list of priority issues to consider when dam removal may be a
possibility. Among the considerations listed are dam and public safety, economics,
environmental concerns, risk, social values and community interests, scientific information, and
stakeholder participation. This report suggests that success of dam removal is dependent upon a
thorough analysis of these competing factors and input from all interested parties (Aspen
Institute, 2002). Often, the dam owner makes the decision to remove a dam, deciding that the
costs of continuing operation and maintenance are greater than the cost of removing the dam.
However, state dam safety offices can order for a dam to be removed if there are safety concerns;
FERC can order removal of dams under their jurisdiction for environmental and safety reasons
(American Rivers, n.d.a.).
State governments have authority over the dams in their jurisdiction. Other state and local
government agencies dealing with issues such as water quality, water rights, and fish and wildlife
protection can also play a role in overseeing dams within their jurisdiction if they so choose
EPA841-B-07-002 9-2 July 2007
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Chapter 9: Dam Removal Requirements, Process, and Techniques
(FOE et al., 1999). Certain states have implemented stringent rules for dams that are and are not
regulated by FERC or USAGE. For example, the state of Wisconsin has a Dam Safety Inspection
Program that requires dams to be inspected every 10 years by the Wisconsin Department of
Natural Resources (WDNR) (Doyle et al., 2000). Any dam that fails to meet safety requirements
set by WDNR must be repaired or removed. The state of Pennsylvania has implemented a law
that was written under the order of the Pennsylvania Fish and Boat Commission that states that
any newly constructed or existing dam that requires a state permit for construction or
modification must also include provisions for fish passage (Doyle et al., 2000).
Some states have programs that aid dam owners in the process of removing their structures. The
Pennsylvania Department of Environmental Protection (DEP) has adopted procedures to make it
easier and less expensive for dam owners to remove unsafe, unused, or unwanted dams. In this
process, owners of dams on third order or larger streams are contacted and asked if they are
interested in removing their dams. If they are, then all the landowners affected by the removal
are contacted, and a public meeting is held if interest warrants one. After public comments, an
engineering design is created, followed by an environmental assessment, then sediment and
erosion control (ESC) plans are established, and finally approval is sought by the USAGE. This
program was used in the removal of seven dams on Conestoga River and also in the removal of
the Williamsburg Station Dam on the Juniata River. This approval process takes between 12 and
18 weeks (FOE et al., 1999). However, the physical decommissioning and removing of a dam
can still be a lengthy and diversified process.
Sediment Removal Techniques
Large dams can trap thousands to millions of cubic yards of sediment over time, eliminating the
flood control or storage capacity of the dam. Removal or control of sediment behind a dam can
represent a large portion of the cost and planning effort of a dam removal project. There are
several methods available to project planners and dam owners that target different pollution
concerns and budgetary limitations (International Rivers Network, 2003). The options in terms of
sediment removal range from complete removal and relocation of all accumulated material from
the inundated regions; removing sediment only from the anticipated channel of the river, or
allowing the river to erode a new channel through the sediment (Wunderlich et al., 1994).
If the sediment is basically clean and the main concern is turbidity and clogging downstream
streambed spawning areas, gradual incremental drawdowns of the reservoir behind the dam
allow the sediment to be transported downstream in smaller portions and avoids the release one
large, lethal volume of sediment. If contaminated sediment is the main concern, dredging is an
option that can be used. While the use of silt curtains can minimize turbidity during dredging, silt
curtains do not contain dissolved substances such as metals, which can pose a threat to
downstream ecosystems (EMC2, 2001). Another option for contaminated sediments is to
stabilize the sediment in place within the stream. This can be accomplished by leaving a portion
of the dam in place to hold back an area of sediment that is of concern. The strategic placement
of boulders can also contain the sediment from moving downstream.
For more information on issues associated with dam removal, see the Additional Resources
section of this document.
EPA841-B-07-002 9-3 July 2007
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http://www.epa.gov/owow/nps/Ecology. Accessed January 2005.
USEPA. 1995b. Erosion, Sediment, andRunoff Control for Roads and Highways. EPA-841-F-
95-008d. U.S. Environmental Protection Agency, Washington, DC.
http://www.epa.gov/owow/nps/education/runoff.html. Accessed January 2005.
USEPA. 1997a. Community-Based Environmental Protection: A Resource Book for Protecting
Ecosystems and Communities. EPA 230-B-96-003. U.S. Environmental Protection Agency,
Washington, DC. http://epa.gov/care/library/howto.pdf. Accessed January 2005.
USEPA. 1997b. Volunteer Stream Monitoring: A Methods Manual. EPA 841-B-97-003. U.S.
Environmental Protection Agency, Washington, DC.
http://www.epa.gov/volunteer/stream/stream.pdf Accessed June 2003.
USEPA. 1998. National Water Quality Inventory: 1996 Report to Congress. EPA 841-R-97-008.
U.S. Environmental Protection Agency, Washington, DC. http://www.epa.gov/305b/96report.
Accessed June 2003.
USEPA. 1999. Storm Water Technology Fact Sheet: Turf Reinforcement Mats. EPA 832-F-99-
002. U.S. Environmental Protection Agency, Washington, DC.
USEPA. 2000. Low Impact Development: A Literature Review. EPA-841-B-00-005. U.S.
Environmental Protection Agency, Washington, DC. http://www.epa.gov/owow/nps/lid/lid.pdf
Accessed May 2007.
USEPA. 2002a. National Water Quality Inventory: 2000 Report to Congress. EPA 841-R-02-
001. United States Environmental Protection Agency, Washington, DC.
http://www.epa.gov/305b/2000report. Accessed June 2003.
USEPA. 2002b. Environmental Assessment for Proposed Effluent Guidelines and Standards for
the Construction and Development Category. EPA 821-R-02-009. U.S. Environmental Protection
Agency, Washington, DC.
http://www.epa.gov/watersci ence/guide/construction/envir/C&D_Envir_Assessmt_proposed.pdf
Accessed June 2003.
USEPA. 2002c. South Myrtle Creek Ditch Project: Removal of Dam Benefits Aquatic Life.
Section 319 Success Stories, Vol. III. EPA 841-S-01-001. U.S. Environmental Protection
Agency, Washington, DC. http://www.epa.gov/owow/nps/Section319III/OR.htm. Accessed
August 2005.
USEPA. 2003 a. Sediment Oxygen Demand Studies. U.S. Environmental Protection Agency, New
England Regional Laboratory, http://www.epa.gov/regionl/lab/ecology/sod.html. Accessed June
2003.
EPA841-B-07-002 References-20 July 2007
-------
References Cited
USEPA. 2003b. National Management Measures to Control Nonpoint Source Pollution from
Agriculture. EPA 841-B-03-004. U.S. Environmental Protection Agency, Washington, DC.
http://www.epa.gov/owow/nps/pubs.html. Accessed May 2003.
USEPA. 2003c. EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature
and Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency,
Seattle, WA.
USEPA. 2005a. National Management Measures to Control Nonpoint Source Pollution from
Forestry. EPA 841-B-05-001. U.S. Environmental Protection Agency, Washington, DC.
http://www.epa.gov/owow/nps/forestrymgmt. Accessed April 2007.
USEPA. 2005b. National Management Measures to Protect and Restore Wetlands and Riparian
Areas for the Abatement of Nonpoint Source Pollution. EPA 841-B-05-003. U.S. Environmental
Protection Agency, Washington, DC. http://www.epa.gov/owow/nps/wetmeasures. Accessed
September 2005.
USEPA. 2005c. Draft Handbook for Developing Water shed Plans to Restore and Protect Our
Waters. EPA 841-B-05-005. U.S. Environmental Protection Agency, Washington, DC.
http://www.epa.gov/nps.
USEPA. 2005d. National Management Measures to Control Nonpoint Source Pollution from
Urban Areas. EPA 841-B-05-004. U.S. Environmental Protection Agency, Washington, DC.
http://www.epa.gov/owow/nps/urbanmm/index.html. Accessed May 2003.
USFWS. 2001. Gas Supersaturation Monitoring Report for Spill Below Bonneville Dam: March
10-13, 2001. U.S. Fish and Wildlife Service, Columbia River Fisheries Program Office,
Vancouver, WA.
http://www.fws.gov/columbiariver/pdfdocs/water/2001%20GBT%20Report.pdf Accessed
September 2005.
USGS. 1997. Sediment Oxygen Demand in the Tualatin River Basin, Oregon, 1992-96. U.S.
Geological Society, Stewart Rounds and Micelis Doyle.
http://or.water.usgs.gov/pubs dir/Html/WRIR97-4103/contents.html. Accessed October 2004.
USGS. 2000. Mississippi. USGS Fact Sheet 025-99. U.S. Geological Survey.
http://pubs.usgs.gov/fs/FS-025-99/pdf/fs-025-99.pdf. Accessed April 2007.
USGS. 2004. An Overview of Coastal Land Loss: With Emphasis on the Southeastern United
States, http://pubs.usgs.gov/of/2003/of03-337/intro.html. Accessed May 2007.
van der Borg, R., and J. Ferguson. 1989. Hydropower and fish passage impacts. In Proceedings
Waterpower '89, American Society of Civil Engineers, Niagara Falls, NY, August 23-25, 1989.
VanderKooy, SJ. and M.S. Peterson. 1998. Critical current speed for young Gulf Coast walleyes.
Transactions of the American Fisheries Society 127(1): 137-140.
EPA841-B-07-002 References-21 July 2007
-------
References Cited
Van Holmes, C., and J. Anderson. 2004. Predicted Fall Chinook Survival and Passage Timing
Under BiOp and Alternative Summer Spill Programs Using the Columbia River Salmon Passage
Model. Columbia Basin Research, University of Washington.
http://www.cbr.washington.edu/papers/2004SummerSpill.pdf. Accessed September 2005.
Wai drop, W.R. 1992. The autoventing turbine, a new generation of environmentally improved
hydroturbines. In Proceedings of the American Power Conference.
Walker, R. and W. Snodgrass. 1986. Model for sediment oxygen demand in lakes. Journal of
Environmental Engineering 112(l):25-43.
Wang, W., 1980. Fractionation of sediment oxygen demand. Water Research 14:603-612.
Washington State Department of Ecology. 1989. Nonpoint source pollution assessment and
management program. Document No. 88-17. Washington State Department of
Ecology, Water Quality Program, Olympia, WA. http://www.ecy.wa.gov/biblio/981813wr.html.
Accessed June 2003.
Watson, C.C., D.S. Biedenharn, and S.H. Scott. 1999. Channel Rehabilitation: Process, Design,
and Implementation. U.S. Army Engineer Research and Development Center, Vicksburg,
Mississippi. http://chl.erdc.usace.army.mi1/Media/2/9/0/ChannelRehabilitation.pdf Accessed
August 2005.
WEF. 1997. The Clean Water Act Desk Reference: 25th Anniversary Edition. Water Environment
Federation, Alexandria, VA.
WRM. 2000. Dam Repair or Removal: A Decision-Making Guide. Water Resources
Management Practicum. http://www.ies.wisc.edu/research/wrmOO. Accessed May 2003.
Watson, C.C., D.S. Biedenharn, and S.H. Scott. 1999. Channel rehabilitation: processes, design,
and implementation. United States Army Corps of Engineers, Engineer Research and
Development Center, Vicksburg, MS.
Welsch, J.D. No date. Riparian Forest Buffers: Function and Design for Protection and
Enhancement of Water Resources. U.S. Department of Agriculture Forest Service, Northeastern
Area State and Private Forestry, Randnor, PA.
Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems. Academic Press. San Diego, CA.
Wilhelms, S.C. 1984. Turbine venting. Environmental & water quality operational studies,
Volume E-84-5, September 1984. U.S. Army Corps of Engineers, Waterways Experiment
Station, Vicksburg, MS.
Wilhelms, S.C. 1988. Reaeration at low-head gated structures; preliminary results. Water
operations technical support, Volume E-88-1, July 1988. U.S. Army Corps of Engineers,
Waterways Experiment Station, Vicksburg, MS.
EPA841-B-07-002 References-22 July 2007
-------
References Cited
Wilhelms, S.C., andD. R. Smith. 1981. Reaeration through gated-conduit outlet works.
Technical Report E-81-5. U.S. Army Corps of Engineers, Waterways Experiment Station,
Vicksburg, MS. Technical Report E-81-5.
Wilhelms, S.C. and L.I. Yates. 1995. Improvement of reservoir releases by aeration. Water
Quality Technical Note MS-01. U.S. Army Corps of Engineers, Vicksburg, MS.
Woodhouse, W.W., Jr. 1978. Dune Building and Stabilization with Vegetation. Special Report
No. 3. U.S. Army Corps of Engineers Coastal Engineering Center, FortBelvoir, VA.
Wunderlich, R.C., B.D. Winter, and J.H. Meyer. 1994. Restoration of the Elwha River ecosystem
and anadromous fisheries. Salmon Ecosystem Restoration: Myth and Reality. Proceedings of the
1994 Northeast Pacific Chinook and Coho Salmon Workshop. American Fisheries Society,
Corvalis, OR.
Wyzga, B. 2001. Impact of channelization-induced incision of the Skawa and Wisloka rivers,
southern Poland, on the condition of overbank deposition. Regulated Rivers: Research and
Management 17(1): 85-100.
Zimmerman, M.J., and M. S. Dortch. 1989. Modelling water quality of a reregulated stream
below a hydropower dam. Regulated Rivers: Research and Management 4:235-247.
EPA841-B-07-002 References-23 July 2007
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Additional Resources
Additional Resources
The following are additional resources that may be used to obtain supplementary information for
topics presented in this document.
Background on Streams, Restoration, and Hydrology
The following are basic references regarding stream ecology, restoration, and hydrology:
Allan, J.D. 1995. Stream Ecology—Structure and Function of Running Waters. Chapman and
Hall, New York.
Brookes, A. andF.D. Shields, eds. 1999. River Channel Restoration: Guiding Principles for
Sustainable Projects. John Wiley and Sons, Chichester, U.K.
Cooke, G.D., E.B. Welch, S.A. Peterson, and P.R. Newroth. 1993. Restoration and Management
of Lakes and Reservoirs. 2nd ed. Lewis Publishers, Boca Raton, FL.
Fischenich, C. 2000. Glossary of Stream Restoration Terms.
http://el.erdc.usace.army.mil/elpubs/pdf/sr01.pdf Accessed October 2004.
Gordon, N.D., T.A. McMahon, and B.L. Finlayson. 1992. Stream Hydrology: An Introduction
for Ecologists. John Wiley and Sons, Chichester, U.K.
Kondolf, G.M. 1995. Five elements for effective evaluation of stream restoration. Restoration
Ecology 3(2): 133-136.
Kondolf, G.M., and E.R. Micheli. 1995. Evaluating stream restoration projects. Environmental
Management 19(1):1-15.
National Research Council (NRC). 1992. Restoration of Aquatic Ecosystems: Science,
Technology, and Public Policy. National Academy Press, Washington, DC.
Poff, N., J.D. Allan, M.B. Bain, J.R. Karr, K.L. Prestegaard, B.D. Richter, R.E. Sparks, and J.C.
Stromberg. 1997. The natural flow regime: A paradigm for river conservation and restoration.
BioScience 47:769-784.
Ponce, V.M. 1989. Engineering Hydrology: Principles and Practices. Prentice-Hall, Englewood
Cliffs, New Jersey.
Rosgen, D.L. 1996. AppliedRiver Morphology. Wildland Hydrology, Colorado.
EPA841-B-07-002 Resources-1 July 2007
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Additional Resources
USEPA. 1995. Ecological Restoration: A Tool to Manage Stream Quality. EPA 841-F-95-007,
U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds,
Washington, DC. http://www.epa.gov/owow/nps/Ecology.
Detailed Information for Practices to Achieve Management Measures
Additional information about practices, their effectiveness, limitations, and cost estimates are
available from a number of sources, including:
Allen, H.H. and J.R. Leech. 1997. Bioengineeringfor Streambank Erosion Control: Report 1
Guidelines. U.S. Army Corps of Engineers, Environmental Impact Research Program, Technical
Report EL-97-8. http://el.erdc.usace.army.mil/elpubs/pdf/trel97-8.pdf
American Society of Civil Engineers and the U.S. Environmental Protection Agency (ASCE and
USEPA). 2007. International Stormwater Best Management Practices (BMPs) Database.
http://www.bmpdatabase.org.
Center for Watershed Protection (CWP). 2007. The Stormwater Manager's Resource Center.
http://www.stormwatercenter.net.
Federal Interagency Stream Restoration Working Group (FISRWG). 1998. Stream Corridor
Restoration: Principles, Processes, and Practices.
http://www.nrcs.usda.gov/technical/stream restoration.
Fischenich, J. C. andH. Allen. 2000. Stream Management. ERDC/EL SR-W-00-1, U.S. Army
Engineer Research and Development Center, Vicksburg, MS.
http://el.erdc.usace.army.mil/elpubs/pdf/srwOO-l/srwOO-l.pdf. Accessed October 2004.
Knutson, P.L., and M.R. Inskeep. 1982. Shore Erosion Control with Salt Marsh Vegetation.
Coastal Engineering Technical Aid No. 82-3. U.S. Army Corps of Engineers Coastal
Engineering Research Center, Vicksburg, MS.
National Association of Home Builders (NAHB). 1995. Storm Water Runoff & Nonpoint Source
Pollution Control Guide for Builders and Developers. National Association of Home Builders,
Washington, DC. http://www.nahbrc.org.
Oregon Association of Conservation Districts. 1999. Protecting Streambanks from Erosion: Tips
for Small Acreages in Oregon, http ://www. or. nrcs .usda. gov/news/factsheets/f s4. pdf .
Urban Drainage and Flood Control District. 1999. Urban Storm Drainage Criteria Manual:
Volume 3—Best Management Practices. Urban Drainage and Flood Control District, Denver,
CO. http://www.udfcd.org.
U.S. Army Corps of Engineers (USAGE). 2007. Engineer Research and Development Center
(ERDC) Web site, http://www.erdc.usace.army.mil.
EPA841-B-07-002 Resources-2 July 2007
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Additional Resources
U.S. Department of Agriculture, Forest Service (USDA-FS). 2002. A Soil Bioengineering Guide
for Streambank and Lake shore Stabilization, http://www.fs.fed.us/publications/soil-bio-guide.
U.S. Environmental Protection Agency (USEPA). 2002. Development Document for Proposed
Effluent Guidelines and Standards for the Construction and Development Category. EPA-821-R-
02-007. http://www.epa.gov/waterscience/guide/construction/devdoc.htm.
U.S. Environmental Protection Agency (USEPA). 2007. National Menu ofStormwaterBest
Management Practices, http://cfpub.epa.gov/npdes/stormwater/menuofbmps/menu.cfm.
Additional information about hydromodification, soil bioengineering, and restoration is available
from the following:
• Ann Riley, Urban Stream Restoration: A Video Tour of Ecological Restoration
Techniques (http://www.noltemedia.com/nm/urbanstream): This video, which can be
ordered online, is a documentary tour of six urban stream restoration sites. It provides
background information on funding, community involvement, and the history and
principles of restoration. The demonstration includes examples of stream restoration in
very urbanized areas, re-creating stream shapes and meanders, creek daylighting, soil
bioengineering, and ecological flood control projects. Ann Riley, a nationally known
hydrologist, stream restoration professional, and executive director of the Waterways
Restoration Institute in Berkley, California, leads the tour.
• California Forest Stewardship Program. Bioengineering to Control Streambank Erosion
(http://ceres.ca.gov/foreststeward/html/bioengineering.html): This fact sheet discusses
various bioengineering techniques applicable to California streams.
• Lower American River Corridor River Management Plan (http ://www. safca.com): The
plan provides information on aquatic habitat management goals, including restoration to
improve aquatic habitat impaired by low flows from channel modification of the Lower
American River.
• Natural Resources Conservation Service, Watershed Technology Electronic Catalog
(http://www.wcc.nrcs.usda.gov/wtec/wtec.html): This online catalog is a source of
technical guidance on a variety of restoration techniques and management practices, to
provide direction for watershed managers and restoration practitioners. The site is
focused on providing images and conceptual diagrams.
• North Delta Improvements Project (http://ndelta.water.ca.gov/index.html): The North
Delta Improvements Project (NDIP), which is under the California Department of Water
Resources, presents unique opportunities for synergy in achieving flood control and
ecosystem restoration goals.
EPA841-B-07-002 Resources-3 July 2007
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Additional Resources
• Ohio Department of Natural Resources. Stream Management Guide Fact Sheets
(http://www.dnr.state.oh.us/water/pubs/fs_st/streamfs.htm): This is a compilation of fact
sheets offering technical guidance for streambank and instream practices, general stream
management, and stream processes.
• Sacramento River Riparian Habitat Program (http://www.sacramentoriver.ca.gov): The
Sacramento River Riparian Habitat Program is working to ensure that riparian habitat
management along the river addresses the dynamics of the riparian ecosystem and the
reality of the local agricultural economy.
• Schueler, T. 1987. Controlling Urban Runoff: A Practical Manual for Planning and
Designing Urban BMPs. Metropolitan Washington Council of Governments,
Washington, DC.
• South Delta Improvements Program
(http://baydeltaoffice.water.ca.gov/sdb/sdip/index_sdip.cfm): The purpose of the South
Delta Improvements Program (SDIP) is to incrementally maximize diversion capability
into Clifton Court Forebay, while providing an adequate water supply for diverters within
the South Delta Water Agency and reducing the effects of State Water Project exports on
both aquatic resources and direct losses offish in the South Delta.
• South Sacramento County Streams Project (http://www.spk.usace.army.mil): South
Sacramento County Streams Project provides flood damage reduction to the urban areas
of the Morrison Creek and Beach Stone Lake drainage basins in the southern area of
Sacramento, as well as around the Sacramento Regional Waste Water Treatment Plant.
The project will fund stream restoration in southern Sacramento County.
• USDA Natural Resources Conservation Service, Stream Visual Assessment Protocol
(http://www.nrcs.usda.gov/technical/ECS/aquatic/svapfnl.pdf): This document outlines
methods for field conservationists and landowners to evaluate stream ecological
conditions.
• Washington State Department of Transportation, Soil Bioengineering Web site
(http://www.wsdot.wa.gov/eesc/design/roadside/sb.htm): This is a comprehensive Web
site, with information on cost, specifications for project design, funding, and case studies.
• WA TERSHEDSS: Water, Soil and Hydro-Environmental Decision Support System
(http://www.water.ncsu.edu/watershedss): The "Educational Component" of this Web
site contains fact sheets with information on a variety of techniques for management
practices, including soil bioengineering and structural streambank stabilization.
EPA841-B-07-002 Resources-4 July 2007
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Additional Resources
Resources for Dams
Thornton, K.W., B.L. Kimmel, and F.E. Payne, eds. 1990. Reservoir Limnology: Ecological
Perspectives. John Wiley and Sons, Inc., New York, NY.
U.S. Army Corps of Engineers. No date. The WES Handbook on Water Quality Enhancement
Techniques for Reservoirs and Tailwaters. U.S. Army Engineer Research and Development
Center Waterways Experiment Station, Vicksburg, MS.
Web sites for dam removal include the following:
• American Rivers' Rivers Unplugged Program:
http://www.americanrivers.org/site/PageServer?pagename=AMR content 1270
• Association of State Dam Safety Officials: http://www.damsafety.org
• Friends of the Earth's River Restoration:
http: //www. foe. org/camp s/reg/nw/ri ver/index. html
• International River Network's River Revival Program: http://www.irn.org/revival/decom
• Massachusetts Department of Fisheries, Wildlife, and Environmental Law Enforcement
River Restore Program:
http://www.mass.gov/dfwele/river/programs/riverrestore/riverrestore.htm
• National Performance of Dams Program Stanford University:
http ://www. Stanford, edu/group/strgeo/researchcenters.html
• New Hampshire Department of Environmental Services:
http://www.des.state.nh.us/dam.htm
• Pennsylvania Department of Environmental Protection, Division of Dam Safety, Dam
Safety Program:
http://www.dep.state.pa.us/dep/deputate/watermgt/we/damprogram/Main.htm
• Pennsylvania Fish & Boat Commission: http://www.fish.state.pa.us
• River Recovery—Restoring Rivers through Dam Decommissioning:
http://www.recovery.bcit.ca/index.html
• United States Society on Dams: http://www.ussdams.org
• Wisconsin Department of Natural Resources:
http://www.dnr.state.wi.us/org/water/wm/dsfm/dams/removal.html
Additional information about dam removal is available from the following resources:
• ASCE. 1997. Guidelines for the Retirement of Hydroelectric Facilities. American Society
of Civil Engineers.
• Bednarek, A.T. 2001. Undamming rivers: A review of the ecological impacts of dam
removal. Environmental Management 27(6):803-814.
• Bioscience. 2002. Dam removal and river restoration: Linking scientific, socioeconomic,
and legal perspectives. Summer (special issue).
• Born, S.M., et al. 1998. Socioeconomic and institutional dimensions of dam removals:
The Wisconsin experience. Environmental Management 22(3):359-370.
EPA841-B-07-002 Resources-5 July 2007
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Additional Resources
• Hart, D.D. and N.L. Poff. 2002. A special section on dam removal and river restoration.
BioScience 52:653-655.
• Heinz Center. 2002. Dam Removal: Science and Decision Making. Available at:
http://www.heinzctr.org/Programs/SOCW/dam_removal.htm.
• International Rivers Network: http://www.irn.org/pubs/wrr.
• Niemi, G.J., et al. 1990. Overview of case studies on recovery of aquatic systems from
disturbance. Environmental Management 14(5):571-587.
• United States Society on Dams Publications: http://www.ussdams.org/pubs.html.
• University of Wisconsin-Madison/Extension. 1996. The Removal of Small Dams: An
Institutional Analysis of the Wisconsin Experience. Extension Report 96-1, May.
Department of Urban and Regional Planning.
• Wisconsin Department of Natural Resources Projects:
http://www.dnr.state.wi.us/org/gmu/sidebar/iem/lowerwis/index.htmtfbaraboo or
http://www.dnr.state.wi.us/org/gmu/lowerwis/baraboo.htm:
http://www.dnr.state.wi.us/org/gmu/sidebar/iem/milw/index.htm:
http://www.dnr.state.wi.us/org/gmu/sidebar/iem/superior/index.htm:
http://www.dnr.state.wi.us/org/gmu/sidebar/iem/sheboygan/index.htm
Noneroding Roadways
The following sources may be used to obtain additional information on noneroding roadways:
• Controlling Nonpoint Source Runoff Pollution from Roads, Highways, and Bridges
http://www.epa.gov/owow/nps/roads.html
• Erosion, Sediment, and Runoff'Controlfor Roads and Highways
http://www.epa.gov/owow/nps/education/runoff.html
• Gravel Roads: Maintenance and Design Manual—the purpose of the manual is to
provide clear and helpful information for doing a better job of maintaining gravel roads.
The manual is designed for the benefit of elected officials, mangers, and grader operators
who are responsible for designing and maintaining gravel roads.
http://www.epa.gov/owow/nps/gravelroads
• Low-Volume Roads Engineering Best Management Practices Field Guide
http://zietlow.com/manual/gkl/web.doc
• Massachusetts Unpaved Roads BMP Manual
http://berkshireplanning.Org/4/download/dirt roads.pdf
• Planning Considerations for Roads, Highways, and Bridges
http: //www. epa. gov/owow/np s/educati on/pi anroad. html
• Pollution Control Programs for Roads, Highways, and Bridges
http://www.epa.gov/owow/nps/education/control.html
• Recommended Practices Manual: A Guideline for Maintenance and Service of Unpaved
Roads http://www.epa.gov/owow/nps/unpavedroads.html
• The "Road Maintenance Video Set" is a five-part video series developed for USDA
Forest Service equipment operators that focuses on environmentally sensitive ways of
maintaining low volume roads, http://www.epa.gov/owow/nps/maint_videoset.html
EPA841-B-07-002 Resources-6 July 2007
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Additional Resources
Additional Information
Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling. 1999. RapidBioassessment
Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and
Fish, Second Edition. EPA 841-B-99-002. U.S. Environmental Protection Agency; Office of
Water; Washington, D.C. http://www.epa.gov/owow/monitoring/rbp/ Accessed July 2007.
International Commission on Large Dams
http://www.icold-cigb.org
International Rivers Network
http://www.irn.org
U.S. Army Corps of Engineers, Engineer Research and Development Center
http://www.erdc.usace.army.mil
U.S. Department of Agriculture, Farm Service Agency
http://www.fsa.usda.gov/pas
U.S. Department of Agriculture, Natural Resources Conservation Service
http://www.nrcs.usda.gov
U.S. Department of the Interior, Bureau of Reclamation
http://www.usbr. gov
U.S. Department of the Interior, National Park Service
http://www.nps.gov
U.S. Department of the Interior, U.S. Fish and Wildlife Service
http ://www.fws. gov
U.S. Department of the Interior, U.S. Geological Survey
http://www.usgs.gov
USEPA. 1994. A State and Local Government Guide to Environmental Program Funding
Alternatives. EPA 841-K-94-001. http://www.epa.gov/owow/nps/MMGI/funding.html
USEPA. 1994. A Tribal Guide to the Section 319(h) Nonpoint Source Grant Program. EPA 841-
S-94-003.
USEPA. 1994. Section 319 Success Stories: Volume I. EPA 841-S-94-004.
http://www.epa.gov/owow/nps/Success319
USEPA. Catalog of Federal Funding Sources for Watershed Protection
http ://cfpub. epa. gov/fedfund
EPA841-B-07-002 Resources-7 July 2007
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Additional Resources
USEPA. 1997. Section 319 Success Stories: Volume II—Highlights of State and Tribal Nonpoint
Source Programs. EPA 841-R-97-001.
http://www.epa.gov/owow/nps/Section319II
USEPA. 2002. Section 319 Success Stories: Volume III.
http://www.epa.gov/owow/nps/Section319III
USEPA Clean Lakes Program
http://www.epa.gov/owow/lakes/cllkspgm.html
USEPA Environmental Finance Information Network (EFIN)
http://www.epa.gov/efmpage/efm.htm
USEPA Nonpoint Source Pollution Control Program Homepage
http ://www. epa. gov/O WOW/NP S
USEPA Surf Your Watershed
http ://www. epa. gov/surf
USEPA Watershed Academy
http://www.epa.gov/owow/watershed/wacademy
Watershedss, (Water, Soil, and HydroEnvironmental Decision Support System)—North Carolina
State University
http://www.water.ncsu.edu/watershedss
EPA841-B-07-002 Resources-8 July 2007
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Appendix A
U.S. Environmental Protection Agency
Contacts
This appendix provides wetlands contacts, nonpoint source regional contacts, and
Clean Water State Revolving Fund Contacts.
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Appendix A
U.S. Environmental Protection Agency
Contacts
EPA is grouped into 10 Regions. For questions about a particular state, contact the appropriate EPA Regional
Coordinator listed below.
EPA Region
Wetland Contact
Nonpoint Source Regional
Coordinators
Clean Water State
Revolving Fund
Regional Coordinators
Region 1:
CT,MA,ME,NH,
RI,VT
http://www.epa.
gov/regionOl/
Region 2:
NJ, NY, PR, VI
http://www.epa.
gov/Region2
Region 3:
DC,DE,MD,PA,
VA,WV
http://www.epa.
gov/region03
Region 4:
AL,FL,GA,KY,
MS,NC,SC,TN
http://www.epa.
gov/region4/
Region 5:
IL,IN,MI,MN,
OH,WI
http://www.epa.
gov/region5/
U.S.EPA-Regionl
Wetlands Protection Unit
One Congress Street
Boston, MA 02114-2023
http://www.epa.gov/regionO II
topics/ecosystems/
wetlands.html
U.S.EPA-Region2
Water Programs Branch
Wetlands Section
290 Broadway
New York, NY 10007-1866
http ://www. epa. gov/region02/
water/wetlands/
U.S. EPA-Region 3
Wetlands Protection
Section
1650 Arch Street (3 WP12)
Philadelphia, PA 19103
http ://www. epa. gov/reg3 esd 1 /
hy dricsoils/index. htm
U.S.EPA-Region4
Wetlands Section
6 IForsyth Street, SW
Atlanta, GA 30303
http://www.epa.gov/region4/
water/wetlands/
U.S. EPA-Region 5
Watersheds and Wetlands
Water Division (W-15J)
77 West Jackson Blvd.
Chicago, IL 60604
http://www.epa.gov/region5/
water/wshednps/
topic_wetlands.htm
U.S.EPA-Regionl
Nonpoint Source Coordinator
One Congress Street,
Boston, MA 02114-2023
http://www.epa.gov/regionO II
topics/water/npsources.html
U.S.EPA-Region2
Water Programs Branch
Nonpoint Source Coordinator
290 Broadway
New York, NY 10007-1866
http ://www. epa. gov/region02/
water/npspage.htm
U.S. EPA-Region 3
Nonpoint Source Coordinator
1650 Arch Street (3 WP 12)
Philadelphia, PA 19103
http: //www. epa. gov/reg3 wapd/
nps/
U.S.EPA-Region4
Nonpoint Source Coordinator
6 IForsyth Street, SW
Atlanta, GA 30303
http ://www. epa. gov/region4/
water/nps/
U.S. EPA-Region 5
Nonpoint Source Coordinator
Water Division (W-15J)
77 West Jackson Blvd.
Chicago, IL 60604
http ://www. epa. gov/region5/
water/wshednps/topic_nps.htm
U.S. EPA-Region 1
SRF Program Contact
One Congress Street
Boston, MA 02114-2023
http://www.epa.gov/ne/cwsrf/
index.html
U.S. EPA-Region 2
Water Programs Branch
SRF Program Contact
290 Broadway
New York, NY 10007-1866
http://www.epa.gov/Region2/
water/wpb/staterev.htm
U.S. EPA-Region 3
Construction Grants Branch
SRF Program Contact
1650 Arch Street (3 WP 12)
Philadelphia, PA 19103
http: //www. epa. gov/reg3 wapd/
srfYindex.htm
U.S. EPA-Region 4
Surface Water Permits & Facilities
SRF Program Contact
6 IForsyth St.
Atlanta GA, 30303
http://www.epa.gov/Region4/
water/gtas/grantprograms.html
U.S. EPA-Region 5
SRF Program Contact
Water Division (W-15J)
77 West Jackson Blvd.
Chicago, IL 60604
http ://www. epa. gov/region5/
business/fs-cwsrf.htm
EPA841-B-07-002 July 2007
A-1
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Appendix A
EPA Region
Wetland Contact
Nonpoint Source Regional
Coordinators
Clean Water State
Revolving Fund
Regional Coordinators
Region 6:
AR,LA,NM,OK,
TX
http://www.epa.
gov/region6
Region 7:
IA,KS,MO,NE
http://www.epa.
gov/region?
Region 8:
CO,MT,ND,SD,
UT,WY
http://www.epa.
gov/region8
Region 9:
AZ,CA,HI,NV,
Pacific Islands
http://www.epa.
gov/region9/
Region 10:
AK, ID, OR, WA
http://www.epa.
gov/regionlO/
General Program
Information
U.S.EPA-Region6
Marine and Wetlands Section
1445 Ross Ave., Suite 1200
Dallas, TX 75202
http://www.epa.gov/region6/
water/ecopro/index.htm
U.S.EPA-Region7
Wetlands Protection
Section (ENRV)
901N. 5th St.
Kansas City, KS 66101
http://www.epa.gov/region7/
wetlands/index, htm
U.S.EPA-RegionS
Wetlands Program
999 18th Street, Suite 500
Denver, CO 80202-2405
http://www.epa.gov/region8/
water/wetlands/wetlands.html
U.S.EPA-Region9
Water Division, Wetlands
75 Hawthorne Street
San Francisco, CA 94105
http://www.epa.gov/region09/
water/wetlands/index.html
U.S. EPA-Region 10
Wetlands Section
1200 SixthAve.
Seattle, WA 98101
http://yosemite.epa.gov/R10/
ECOCOMM.NSF/webpage/
Wetlands
U.S. EPA
Wetlands Division (4502F)
Mail Code RC-4100T
1200 Pennsylvania Ave., NW
Washington, DC 20460
http: //www. epa. gov/o wo w/
wetlands/
U.S. EPA-Region 6
Nonpoint Source Coordinator
1445 Ross Ave., Suite 1200
Dallas, TX 75202
http ://www. epa. gov/region6/
water/ecopro/watershd/
nonpoint/
U.S. EPA-Region 7
Nonpoint Source Coordinator
90IN. 5thSt.
Kansas City, KS 66101
U.S.EPA-RegionS
Nonpoint Source Coordinator
999 18th Street, Suite 300
Denver, CO 80202-2405
http ://www. epa. gov/region8/
water/nps/contacts.html
U.S. EPA-Region 9
Nonpoint Source Coordinator
75 Hawthorne Street
San Francisco, CA 94105
http: //www. epa. gov/regionO 91
water/nonpoint/index.html
U.S. EPA-Region 10
Nonpoint Source Coordinator
1200 SixthAve.
Seattle, WA98101
U.S. EPA Nonpoint Source
Control Branch (4503 -T)
Ariel RiosBldg.
1200 Pennsylvania Ave., NW
Washington, DC 20460
http ://www. epa. gov/o wo w/nps
U.S.EPA-Region6
SRF Program Contact
1445 Ross Ave., Suite 1200
Dallas, TX 75202
http ://www. epa. gov/Arkansas/
6en/xp/enxp2c4. htm
U.S. EPA-Region 7
SRF Program Contact
90IN. 5thSt.
Kansas City, KS 66101
http://www.epa.gov/Region7/
water/srf.htm
U.S.EPA-RegionS
SRF Program Contact
999 18th Street, Suite 300
Denver, CO 80202-2405
U.S. EPA-Region 9
Construction Grants Branch
SRF Program Contact
75 Hawthorne Street
San Francisco, CA 94105
http://www.epa.gov/region9/
funding/
U.S. EPA-Region 10
Ecosystems & Communities
SRF Program Contact
1200 Sixth Ave.
Seattle, WA 98101
http://yosemite.epa.gov/rlO/
ecocomm. nsf/webpage/
Clean+Water+State+Revolving
+Fund+in+Region+10
U.S. EPA
The Clean Water State
Revolving Fund Branch
(4204M)
1201 Constitution Ave., NW
Washington, DC 20004
http://www.epa.gov/owm/
cwfinance/cwsrf/index.htm
A-2
EPA841-B-07-002 July 2007
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