300R04904
KING WILLIAM
RESERVOIR PROJECT
RESERVOIR MITIGATION PLAN
Prepared on Behalf of
Regional Raw Water Study Group
June 2004
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ES-1
1.0 PROCESS AND HISTORY OF THE KING WILLIAM RESERVOIR
MITIGATION PLAN 1-1
1.1 Introduction 1-1
1.2 The State and Federal Permit Process and the RRWSG's Efforts 1-2
1.3 Regulatory Involvement 1-2
1.4 Draft EIS (February 1994) 1-3
1.5 Supplement to the DEIS (December 1995) 1-4
1.6 Conceptual Mitigation Plan for the DEQ (August 1996) 1-5
1.7 Final EIS (January 1997) 1-6
1.8 Wetland Mitigation Pilot Study (September 1997) 1-7
1.9 Reservoir Fringe Study (October 1997) 1-8
1.10 Draft Wetland Mitigation Plan (October 1997) 1-9
1.11 Virginia Water Protection Permit (VWP Permit No. 93-0902) (December 22, 1997) 1-10
1.12 Working Draft Mitigation Plan (July 1998) 1-10
1.13 Final Habitat Evaluation Procedures Report (February 1999) 1-12
1.14 Final Fish and Wildlife Mitigation Plan (May 1999) 1-12
1.15 Final Wetland Mitigation Plan (May 1999) 1-13
1.16 RRWSG's Reservoir Mitigation Plan (December 2003) 1-14
1.17 Summary of Reservoir Mitigation Plan 1-15
2.0 MITIGATION SITE SELECTION 2-1
2.1 History of Mitigation Site Selection 2-1
2.2 Site Selection Process 2-11
2.3 Site Screening and Identification 2-11
2.3.1 Geographic Considerations 2-11
2.3.2 Site Identification and Selection Criteria 2-12
2.4 Preliminary Evaluation 2-13
2.5 Site Access 2-14
2.6 Site Reconnaissance and Review 2-14
2.7 Selected Sites 2-15
3.0 PARTICIPANTS IN PLAN DEVELOPMENT 3-1
4.0 WETLAND MITIGATION COMPONENT 4-1
4.1 Wetland Mitigation Sites 4-1
4.1.1 King William Farm 4-2
4.1.2 York River Mitigation Bank 4-4
4.1.3 Meadow Farm 4-4
4.1.4 Burlington 4-6
4.1.5 Lanesville 4-7
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4.1.6 Gulasky 4-8
4.1.7 Townsend 4-9
4.1.8 The Island 4-10
4.1.9 Terrell 4-11
4.1.10 Rice 4-12
4.1.11 Davis 4-14
4.2 Contingency Mitigation Sites 4-15
4.3 Requirements for Wetland Compensatory Mitigation 4-16
4.3.1 Definitions 4-16
4.3.2 Requirements for Final Wetland Mitigation Site Designs and
Specifications 4-16
4.3.3 Success Criteria for Wetland Mitigation Sites 4-22
4.3.4 Monitoring Report Criteria 4-25
4.3.5 Post Monitoring Assessment 4-27
4.3.6 Performance Bond 4-28
4.4 Cultural Resources within the Mitigation Sites 4-28
4.5 Regulatory Guidance Letter 02-2 4-29
4.6 References 4-30
5.0 COHOKE CREEK DOWNSTREAM PROTECTION 5-1
5.1 Introduction 5-1
5.2 Avoidance and Minimization of Downstream Wetland Impacts 5-1
5.3 Minimum Reservoir Releases 5-5
5.4 Contributing Drainage Area Below Dam Site IV 5-8
5.5 Natural Flow Regime 5-10
5.6 Sediment Loading and Wetland Maintenance 5-13
5.7 Water Temperature Maintenance 5-15
5.8 Comparisons to Release from Other Reservoirs 5-15
5.9 Stream Corridor Preservation 5-16
5.10 Conclusion 5-17
6.0 STREAM AND RIPARIAN CORRIDOR MITIGATION COMPONENT 6-1
6.1 Introduction 6-1
6.2 Stream Mitigation Goals 6-2
6.3 Mitigation Credit Calculation 6-2
6.4 Stream Mitigation Site Selection/Analysis 6-3
6.5 Component Implementation 6-8
6.6 Monitoring and Deed Restriction 6-11
6.7 Summary 6-11
6.8 References 6-11
7.0 FISH AND WILDLIFE HABITAT MITIGATION COMPONENT 7-1
7.1 Introduction 7-1
7.1.1 Avoidance, Minimization and Compensation 7-2
7.1.2 Purpose of the Fish and Wildlife Habitat Component 7-3
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7.2 Affected Environment and Environmental Consequences 7-4
7.2.1 Wetlands Within The Reservoir Pool Area 7-4
7.2.2 Wetland Evaluation Technique 7-4
7.2.3 Evaluation for Planned Wetlands 7-5
7.2.4 Habitat Evaluation Procedures Gross Losses Analysis 7-6
7.2.5 Pipeline 7-8
7.2.6 Riparian Corridor 7-9
7.2.7 Fisheries 7-9
7.2.8 Upland Habitat 7-10
7.2.9 Threatened and Endangered Species 7-10
7.2.10 Cohoke Creek Downstream Wetlands 7-12
7.3 Project Benefits 7-12
7.3.1 Regional Approach 7-12
7.3.2 Water Supply Benefits 7-12
7.3.3 Host Community Benefits 7-13
7.3.4 Project Configuration Benefits 7-14
7.3.5 Recreation Benefits 7-14
7.3.6 Fisheries Benefits 7-15
7.3.7 Wildlife Benefits 7-15
7.3.8 Land Conservation Benefits 7-15
7.3.9 Natural Community Benefits 7-16
7.4 Mitigation Plan Goals and Elements 7-17
7.4.1 Mitigation Plan Goal 7-18
7.4.2 Mitigation Plan Elements 7-18
7.5 Wetland Creation/Restoration 7-20
7.5.1 Wetlands Creation/Restoration 7-20
7.5.2 Contingency Sites 7-21
7.5.3 Preservation Agreements 7-21
7.5.4 Summary 7-21
7.6 Reservoir 7-21
7.6.1 Reservoir Functions 7-22
7.6.2 Lacustrine Habitat 7-22
7.6.3 Shoreline Habitat 7-23
7.6.3.1 Comparable Shoreline Wetland Systems 7-24
7.6.3.2 Shoreline Wetlands under Section 404 7-24
7.6.3.3 Shoreline Wetlands and Reservoir Operations 7-25
7.6.4 Recreational Opportunities 7-27
7.7 Stream Corridor Restoration/Preservation 7-27
7.8 Fisheries 7-28
7.8.1 Raw Water Intake on the Mattaponi River 7-28
7.8.2 Reservoir Pool Area 7-29
7.8.3 Fish Passage 7-29
7.8.4 Fish Hatchery Improvements 7-29
7.9 Other Environmental Elements 7-29
7.9.1 Upland Restoration and Preservation 7-29
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7.9.2 Endangered Species 7-31
7.9.3 Cohoke Creek Downstream Wetlands 7-32
7.9.4 Wetland Education 7-32
7.9.5 Best Management Practice for Water Quality Protection 7-32
7.10 Summary 7-33
7.11 References 7-34
8.0 FUNCTIONAL ASSESSMENT 8-1
8.1 Functional Analysis Development 8-1
8.1.1 Introduction 8-1
8.1.2 Functional Analysis History 8-1
8.1.3 Wetland Evaluation Technique 8-2
8.1.4 Evaluation for Planned Wetlands 8-2
8.1.5 Habitat Evaluation Procedures - Gross Losses Analysis 8-3
8.1.6 Priority Function Development 8-3
8.2 Planned Components 8-4
8.2.1 Wetland Mitigation Sites 8-4
8.2.2 Deep Water Habitat 8-5
8.2.3 Shoreline Wetlands and Shallow Water Habitat 8-5
8.2.4 Reservoir Buffer and Upland Habitat Preservation 8-6
8.2.5 Downstream Preservation Area 8-6
8.2.6 Stream Corridor Restoration/Preservation 8-6
8.2.7 Fish Passage Restoration 8-7
8.2.8 Fish Hatchery Improvements 8-7
8.2.9 Wetland Education Opportunities 8-8
8.3 Ecosystem Support 8-8
8.3.1 Primary Productivity 8-8
8.3.2 Assessment Assumptions 8-8
8.3.3 Methodology 8-9
8.3.4 Results 8-9
8.4 Water Quality 8-10
8.4.1 Sediment Retention and Nutrient Assimilation 8-10
8.4.2 Assessment Assumptions 8-10
8.4.3 Methodology 8-11
8.4.4 Results 8-12
8.5 Fish and Wildlife Habitat 8-12
8.5.1 Overview of HEP 8-12
8.5.2 HEP Analysis of the Mitigation Plan 8-13
8.5.3 Conclusion 8-14
8.6 Landscape Interspersion/Connectivity within the Project Area 8-14
8.6.1 Overview of the Mitigation Plan 8-14
8.6.2 Conclusion 8-15
8.7 Functional Assessment Conclusions 8-16
8.8 References 8-17
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9.0 ASSURANCES FOR SUCCESSFUL IMPLEMENTATION 9-1
9.1 Assurances for Mitigation Success 9-1
9.1.1 Corps/USEPA Model Compensatory Mitigation Plan Checklist 9-1
9.1.2 Requirements for Compensatory Wetland Mitigation 9-1
9.1.3 20-Year Monitoring Period 9-2
9.1.4 Contingency Measures 9-2
9.1.5 Adaptive Management 9-2
9.1.6 VDEQ/USACE Approval and Public Notice 9-2
9.1.7 Financial Assurances 9-3
9.1.8 Protection in Perpetuity 9-3
10.0 MITIGATION COMMITMENTS 10-1
10.1 Summary of RRWSG Mitigation Commitments 10-1
LIST OF TABLES
Table On or
No. Description Following
Page
3-1 Participants in Plan Development 3-1
4-1 Wetland Restoration/Creation Acreages Proposed within the Mitigation Sites
Contingency Sites 4-1
4-2 Status of Section 106 Activities 4-28
6-1 King William Reservoir Stream Impacts 6-1
6-2 Stream Mitigation Site Analysis 6-4
6-3 Stream Mitigation Summary 6-4
6-4 Stream Mitigation Miles 6-7
6-5 Stream Impact to Mile-Credit Balance Sheet 6-8
7-1 Mitigation Elements and Benefits 7-3
7-2 Summary of Wet Analysis Results - King William Reservoir
Dam Site II Wetlands 7-5
LIST OF TABLES
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LIST OF TABLES
Table On or
No. Description Following
Page
7-3 Gross Losses in the KWR-IV Reservoir Pool Area 7-8
7-4 Occurrence of Fish Species in Reservoir Environments
Cohoke Creek Non-tidal Water Above Cohoke Millpond 7-10
7-5 Typical Fish and Wildlife of the Lacustrine Community 7-22
7-6 Littoral Zone Area of Representative Reservoirs 7-24
8-1 Mitigation Components Functional Replacement 8-4
8-2 Acreage Estimates for the Wetland Mitigation Sites and Contingency Sites 8-4
8-3 Mitigation Sites Functional Replacement 8-5
8-4 Evaluation of Net Primary Productivity Functions 8-9
8-5 Evaluation of the Water Quality Functions of the King William Reservoir Project 8-12
8-6 HEP Evaluation Species Habitat Gains with Mitigation Implementation 8-13
LIST OF FIGURES
Figure Following
No. Description Page
4-1 Wetland Mitigation Site Locations 4-1
4-2 King William Farm Property Conceptual Layout and Surrounding Conditions 4-3
4-3 Gulasky Property and York River Mitigation Bank Conceptual
Layout and Surrounding Conditions 4-4
4-4 Burlington and Meadow Farm Properties Conceptual Layout and Surrounding
Conditions 4-5
4-5 Lanesville Property Conceptual Layout and Surrounding Conditions 4-7
4-6 Townsend Property Conceptual Layout and Surrounding Conditions 4-9
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(Continued)
LIST OF FIGURES
Figure
No.
4-7
4-8
Following
Description Page
The "Island
Terrell Prop
and Rice Properties Conceptual Layout and Surrounding Conditions
erry Conceptual Layout and Surrounding
4-10
Conditions 4-11
4-9 Davis Farm Property Conceptual Layout and Surrounding
Conditions 4-14
4-10 New Kent Environmental Bank Conceptual Layout and
Surrounding Conditions 4-15
4-11 Myers Property Conceptual Layout and Surrounding
Conditions 4-15
4-12 Eocene Property Conceptual Layout and Surrounding
Conditions 4-15
6-1 Cohoke Creek and Tributaries Conceptual Stream Preservation Corridors 6-4
6-2a Gulasky and York River Mitigation Bank Properties Conceptual Stream
Mitigation 6-4
6-2b Gulasky Property Site Photos 6-4
6-2c York River Mitigation Bank Property Site Photos 6-4
6-3a Burlington and Meadow Farm Properties Conceptual Stream Mitigation 6-4
6-3b Burlington and Meadow Farm Properties Site Photos 6-4
6-4a Davis Farm Property Conceptual Stream Mitigation 6-4
6-4b Davis Farm Property Site Photos 6-4
6-5a The 'Island' and Rice Properties Conceptual Stream Mitigation 6-4
6-5b The 'Island' and Rice Properties Site Photos 6-4
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Figure
No.
LIST OF FIGURES
Description
Following
Page
6-6a Lanesville Property Conceptual Stream Migitation 6-4
6-6b Lanesville Property Site Photos 6-4
6-7a King William Farm Property Conceptual Stream Mitigation 6-4
6-7b King William Farm Property Site Photos 6-4
6-8 Terrell Property Conceptual Stream Mitigation 6-4
6-9 Townsend Property Conceptual Stream Mitigation 6-4
6-10 Green Springs Stream Corridor Conceptual Stream Mitigation 6-4
6-1 la Green Springs Stream Corridor Conceptual Stream Mitigation 6-4
6-llb Green Springs Stream Site Photos 6-4
6-1 Ic Green Springs Stream Site Photos 6-4
6-lld Green Springs Stream Site Photos 6-4
7-1 Wetland Mitigation Site Locations 7-20
7-2 Shoreline Wetlands at Waller Mill Reservoir Site Photos 7-23
7-3 Shoreline Wetlands at Beaver Dam Swamp Reservoir - Site Photos 7-23
7-4 Shoreline Wetlands at Little Creek Reservoir Site Photos 7-23
7-5 Shoreline Wetlands at Diascund Creek Reservoir - Site Photos 7-23
7-6 Shoreline Wetlands at Lee Hall Reservoir Site Photos 7-23
8-1 Wetland Mitigation Site Locations 8-15
8-2 Gulasky Property and York River Mitigation Bank Conceptual Layout and
Surrounding Conditions 8-15
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Figure
No.
TABLE OF CONTENTS
(Continued)
LIST OF FIGURES
Description
Following
Page
8-3 Burlington Farm and Meadow Farm Properties Conceptual Layout and
Surrounding Conditions 8-15
8-4 Davis Farm Property Conceptual Layout and
Surrounding Conditions 8-15
8-5 The 'Island' and Rice Properties Conceptual Layout and
Surrounding Conditions 8-15
8-6 Lanesville Property Conceptual Layout and Surrounding Conditions 8-15
8-7 King William Farm Property Conceptual Layout and
Surrounding Conditions 8-15
8-8 Terrell Properties Conceptual Layout and
Surrounding Conditions 8-15
8-9 Townsend Property Conceptual Layout and Surrounding Conditions 8-15
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EXECUTIVE SUMMARY
INTRODUCTION
The North Atlantic Division, U.S. Army Corps of Engineers (Corps) has determined that the King
William Reservoir, along with conservation measures and utilization of limited groundwater supplies, is
the least environmentally damaging practicable alternative to meet the long-term water supply needs of
the Lower Virginia Peninsula ("Decision Memorandum for King William Reservoir Project, Norfolk
District Application No.93-0902-12, September 2002). Under the guidance of the Corps and other federal
agencies, the Regional Raw Water Study Group (RRWSG) has identified environmental impacts that may
be realized with construction of the King William Reservoir. These potential impacts were studied,
investigated, modeled, and in.some cases refinements to the project were made and impacts evaluated
again. As part of the mitigation process, extensive measures to avoid and minimize environmental
impacts have been undertaken to include relocation of the dam, redesign of the intake, relocation of the
outfall, and realignment of pipeline facilities. However, some impacts are unavoidable and must be
satisfactorily mitigated in order to allow the project to be found in compliance with Section 404 (b) (1) of
the Clean Water Act Guidelines.
The reservoir mitigation plan represents the culmination of a long, involved process in which numerous
federal and state agency representatives and wetland mitigation experts provided detailed directives and
review at virtually every step of the way. However, the result, as mandated by the February 1990
"Memorandum of Agreement Between the Environmental Protection Agency and the Department of the
Army Concerning the Determination of Mitigation under the Clean Water Act Section 404 (b)(l)
Guidelines" (Joint MOA), as well as the Corps' RGL 02-2 and 33 CFR 320.4 (r) is a reservoir mitigation
plan that identifies appropriate and practicable methods and strategies that will be employed to offset
impacts to aquatic and terrestrial resources within the reservoir project area.
The reservoir mitigation plan, when successfully implemented, will exceed the goal of compensating for
the loss of wetland acreage and function, and will also provide mitigation for other potential
environmental impacts resulting from the reservoir project. The applicant completed a rigorous wetland
mitigation site selection process, which was driven by the Corps, the U.S. Environmental Protection
Agency (USEPA), the U.S. Fish and Wildlife Service (USFWS), and the Virginia Department of
Environmental Quality (VDEQ). The wetland restoration/creation element will offset the loss of the 403
acres of vegetated wetlands in the reservoir pool, at a ratio of 2 acres for every acre lost (2:1 acreage
compensation). Recognizing -that the selected mitigation sites were chosen for their excellent
characteristics and their high probability for wetlands establishment success, the 2:1 acreage replacement
would achieve functional replacement. In effect, the King William Reservoir project and its
accompanying mitigation will exchange 403 acres of wetlands that exhibit certain elements of separation
the greater Chesapeake Bay Watershed by the downstream Cohoke Millpond, for 806 acres of wetlands
that are all directly connected to tributaries of the Bay.
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AVOIDANCE AND MINIMIZATION OF WETLAND IMPACTS
Since initial project planning efforts in 1989, the KRWSG has adhered to the Section 401 and Section 404
permit programs, National Environmental Policy Act (NEPA) regulations, and guidance from the VDEQ,
the Corps, USEPA, USFWS, and other federal and state agencies.
As a first step, the RRWSG undertook formal NEPA "scoping" to identify the issues and alternatives for
analysis in an EIS. More than 30 alternatives were identified and reviewed for availability, practicability,
and for their environmental effects, all of which involved the federal and Virginia regulatory agencies.
From these alternatives, the King William Reservoir Project emerged as the RRWSG's preferred project,
which involves a system of integrated water sources including fresh and brackish groundwater
development, use restrictions, conservation, and the creation of a 1,526-acre reservoir.
In the coastal plain of Virginia, it is impossible to construct a reservoir without some wetland impacts.
However, every effort has been made in the design of the King William Reservoir project to reduce
unavoidable impacts to the maximum extent possible.
The 1990 Memorandum of Agreement (MOA) between the USEPA and the Department of the Army
addresses the policies and procedures to be used in the determination of the type and level of mitigation
necessary to demonstrate compliance with the Clean Water Act Section 4()4(b)(l) Guidelines
(Guidelines). Specific mitigation requirements are defined by the mitigation sequencing rules: avoidance,
followed by minimization, and finally applicants must provide compensation for the remaining wetlands
impacted by discharges.
The first sequencing step, avoidance, requires an evaluation of practicable alternatives by permit
applicants to confirm that the selected project will have the least adverse impact on the environment. As
concluded in the September 2002 Corps Decision Memorandum for the project, "the King William
Reservoir, along with conservation measures and utilization of groundwater supplies, is the least
environmentally damaging practicable alternative to meet the waters needs of the lower Virginia
peninsula."
The second sequencing step requires permit applicants to make appropriate and practicable efforts to
minimize unavoidable impacts. The RRWSG exercised the principles of avoidance and minimization by
locating the reservoir within a stream segment where wetlands are already separated from direct
connection to the Pamunkey River by the existing Cohoke Millpond, located approximately 3.5 miles
downstream of the currently proposed Dam Site IV. The 300-year-old Cohoke Millpond dam cuts off the
tidal connection from the downstream wetlands and Pamunkey River. The Cohoke Millpond dam also
blocks both anadromous and freshwater fish movements, disrupts migratory patterns of other aquatic
organisms, and reduces sediment and organic matter transport to the downstream wetlands.
The RRWSG's currently proposed project (Dam Site IV) is a clear example of efforts to minimize
wetland impacts. At the direction of the Norfolk District Corps of Engineers, and recommendations by
the USFWS and USEPA, the RRWSG relocated the proposed dam site 1.7 miles upstream from the
original location (Dam Site I) to Dam Site IV, to reduce wetland impacts by 216 acres. This wetlands
savings resulted in a 9 billion gallon (42 percent) reduction in storage capacity from 21.2 to 12.2 billion
gallons. King William Reservoir storage capacity has already been reduced as much as possible such that,
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EXECUTIVE SUMMARY
in combination with already implemented conservation programs and brackish groundwater desalination,
it is still able to meet the basic project purpose.
The RRWSG also exercised the principles of avoidance and minimization by redesigning the Mattaponi
River intake, relocating the outfall on Beaverdam Creek, and realigning pipeline facilities to minimize
environmental impacts.
AFFECTED ENVIRONMENT
The project would inundate approximately 403 acres of freshwater, non-tidal wetlands and approximately
34 acres of open water within the reservoir pool. These areas would not be directly impacted by the
regulated discharge of fill material, but would experience secondary impacts resulting from modification
of their current aquatic functions.
Approximately 21 miles of nontidal, perennial and intermittent streams in the reservoir pool area will be
converted to a lacustrine system with deepwater habitat and shallow shoreline areas. The reservoir will
also fill or inundate approximately 1,089 acres of uplands. Most of these uplands are periodically clear-
cut. The project would also inundate potential habitat for a federally-threatened plant, the Small Whorled
Pogonia.
The project will result in temporary impacts to 6 acres of vegetated wetlands and 1 acre of open water in
conjunction with installation of water conveyance pipelines. Installation of the pipelines would comply
with the construction and management practices specified by the Department of the Army as part of the
Nationwide General permit Program. Impacts within the pipeline right-of-way would be temporary and
affected areas would eventually revert to their original functions as streams and wetlands, although
approximately 3.5 acres of the recovered wetland areas would be comprised of a different dominant
vegetation type.
OVERVIEW OF THE RESERVOIR MITIGATION PLAN
The purpose of this document is to provide the methods and strategies that will be employed to
compensate for impacts to aquatic resources in the reservoir project area, as well as offsetting impacts to
other resources.
The components of this reservoir mitigation plan total approximately 6,100 acres of wetlands, uplands,
and open water to be restored, created, and preserved. Detailed functional assessment demonstrates that
this mitigation plan will more than offset the impacts associated with the loss of the 403 acres of
vegetated wetlands, riparian habitat, wetland cover type conversion associated with the pipeline, and the
conversion of upland forest areas to open water. Implementation of the RRWSG's reservoir mitigation
plan will fully compensate for impacts by achieving "no net loss" of wetland acreage or functions.
Additional compensation will be provided by wetland preservation, lacustrine habitat creation, shoreline
habitat creation, stream corridor restoration, upland restoration and preservation. The RRWSG's
reservoir mitigation plan is unprecedented in both its scope and the level of detail provided for a pre-
permit proposal.
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The interagency mitigation team, including representatives of the Corps, USEPA, USFWS, and a VDEQ,
was intimately involved in the selection and conceptual design of the mitigation sites. The RRWSG has
identified over 806 acres of potential wetland restoration and creation areas within the Chesapeake Bay
watershed that can be used to offset the wetland functions and values associated with the loss of 403 acres
of vegetated wetlands within the reservoir pool area at a 2:1 compensation ratio. Most of the mitigation
sites are adjacent to surface watercourses and extensive tracts of existing wetlands and uplands that will
be protected and preserved. A large majority of the wetland mitigation acreage consists of restoration of
previously degraded wetlands, which is the most successful type of mitigation.
The Norfolk District, USEPA, USFWS, and VDEQ defined the goal for the RRWSG's reservoir
mitigation plan as "no net loss of wetland acreage and function." Although the Joint MOA does not
require full functional replacement of each individual function that would be lost from implementation of
the project, the RRWSG has offered a mitigation plan that will more than offset the wetland acreage and
functions lost from the proposed reservoir project. The mitigation plan also offers methods and strategies
to offset other functions impacted by the reservoir.
The 2:1 mitigation ratio is itself an appropriate and practicable way to compensate for the asserted
functional differences in the Cohoke Creek wetlands and the mitigation sites. As stated in the 1990 MOA
(section III.B), "In the absence of more definitive information on the functions and values of specific
wetland sites, a minimum of 1 to 1 acreage replacement may be used as a reasonable surrogate for no net
loss of functions and values. However, this ratio may be greater where the functional values of the area
being impacted are demonstrably high and the replacement wetlands are of lower functional value or the
likelihood of success of the mitigation project is low."
Over half of the mitigation sites are larger than 150 acres (total size) and construction of the three largest
mitigation sites alone would provide 1:1 wetland acreage compensation. In addition to the 806 acres of
wetland restoration/creation, the mitigation sites include preservation of at least 315 acres of wetlands and
over 700 acres of upland habitat, connecting the existing and newly restored or created forested wetland
systems and forming extensive ecosystem complexes that will include wetland, riverine, and forested
upland habitats. The smallest of the mitigation sites (Davis Farm) includes 10 acres of wetland
restoration/creation, but the total mitigation project area is 42 acres. The largest of the sites (Terrell)
includes 195 acres of wetland restoration/creation, in an overall mitigation site of approximately 380
acres. The proposed mitigation will restore large portions of riparian corridors that were previously
cleared and drained, and the combined systems will blend together or complement each other as they
mature into diverse communities. These large, contiguous wetland-upland systems will provide
substantial water quality and wildlife habitat benefits.
Recognizing that the selected mitigation sites were chosen for their excellent characteristics and their high
probability for wetlands establishment success, the 2:1 acreage replacement ratio alone would achieve full
wetland functional replacement.
In addition to the wetland mitigation sites, approximately 200 acres of vegetated wetlands and 122 acres
of shallow open water are expected to develop around the margins of the new King William Reservoir.
The project will thus result in a net gain of 603 acres of restored/created wetlands (806 + 200 - 403 =
603), and over 300 additional acres of wetlands within the mitigation sites will receive perpetual
protection.
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The mitigation sites are bordered by rivers or streams with some sites experiencing occasional overbank
flooding. Many of the mitigation sites include stream corridor restoration within the wetland restoration
area. Stream corridor restoration, enhancement, and protection will help to compensate for the loss of
functions and values of the impounded portions of Cohoke Creek.
Another component of the RRWSG's mitigation plan includes protection of a colony of a federally-
threatened plant, the Small Whorled Pogonia. The RRWSG is also engaged in consultations under
Section 106 of the National Historic Preservation Act with the Pamunkey and Mattaponi Indian Tribes,
the COE and other agencies, aimed at designing appropriate mitigation for potential impacts to tribal
cultural resources. One set of alternatives includes possible financial or other support for such activities
as developing Tribal environmental regulations, training and education of Tribal members in
environmental sciences, particularly wetlands, developing a database describing specific wetland
parameters associated with wetlands on the Tribes' Reservations, and providing access to the wetlands by
construction of elevated walkways and trails.
HISTORY OF WETLAND MITIGATION DEVELOPMENT
The final wetland mitigation component of the reservoir mitigation plan is the culmination of more than
ten years of interagency coordination and mitigation planning. Many drafts of the mitigation plan were
developed and revised based on agency comments. In an effort to develop a mitigation plan that was
acceptable to the regulatory agencies, the RRWSG spearheaded development of a mitigation team
comprised of representatives of the Corps, USEPA, USFWS, VDEQ and RRWSG. Recently, the
Virginia Department of Historic Resources (VDHR) joined the mitigation team to ensure compliance with
Section 106 of the National Historic Preservation Act. The mitigation team identified wetland mitigation
goals, site selection criteria and requirements for final mitigation plan development. Other organizations
were often invited to participate in the mitigation team meetings and provide input.
SITE SELECTION PROCESS
A site selection process was designed in coordination with the interagency mitigation team to identify
optimal areas for wetland restoration and creation. The process was continually refined in response to
agency directives. The site selection process was followed to maximize the probability of establishing
fully functional wetland systems. Selection of potential wetland mitigation sites was pursued through a
sequential process of site screening, preliminary evaluation of site features, obtaining access to sites and
establishing landowner willingness to consider participation in a wetland mitigation project. A screening
process was used to identify sites with desirable features for wetland mitigation and eliminate those with
undesirable features. A qualitative ranking was used in the preliminary evaluation phase to classify the
identified sites into groups of high, medium and low potential for wetland mitigation.
Once access to properties from the individual counties and landowners was obtained, meetings with
landowners and site reviews were conducted to confirm each site's potential for wetland mitigation. The
federal and state agencies required that wetland mitigation offset the in-kind losses associated with the
Cohoke Creek riparian wetland system. Therefore, mitigation site selection focused on the identification
of potential restoration areas located immediately adjacent to streams or river systems.
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EXECUTIVE SUMMARY
More than 250 potential mitigation sites were investigated and rejected for various reasons (i.e., minimum
size requirements, isolation from streams or existing wetlands, substantial excavation required, avoiding
mature forested areas to prevent loss of existing habitat, etc,). The interagency mitigation team has
accepted the candidate and contingency mitigation sites, and preservation areas, as well as the tentative
acres as described in the plan because the sites contain characteristics which increase the probability of
wetland mitigation success, given proper final designs, review agency involvement, construction
oversight, monitoring, and remediation...
PARTICIPANTS IN RESERVOIR MITIGATION PLAN DEVELOPMENT
The reservoir mitigation plan represents the culmination of a long, detailed process in which numerous
federal and state agency representatives and wetland mitigation experts provided directives and review at
virtually every step of the way. In addition to the interagency mitigation team, other state and federal
agencies, academic wildlife and wetland experts, local Indian Tribes, and special interest groups were
often invited to participate in the mitigation team meetings. For example, initial mitigation team meetings
also included representatives of the Virginia Department of Conservation and ELecreation, Virginia
Department of Game and Inland Fisheries (VDGIF), Virginia Institute of Marine Science (VIMS), The
Nature Conservancy, Chesapeake Bay Foundation, Sierra Club, and Environmental Concern, Inc.
WETLAND MITIGATION COMPONENT
2:1 Compensation
Wetland mitigation has been proposed by the RRWSG for the proposed King William Reservoir project
in support of their application for a Section 404 permit from the Corps. The mitigation plan describes the
strategies that will be used to offset the unavoidable wetland impacts associated with the construction of
the reservoir in compliance with criteria set forth by the Corps for wetland mitigation.
The RRWSG engaged in a fully integrated team effort with the Corps and its advisoiy agencies to select
mitigation sites acceptable to all. The interagency mitigation team has accepted the candidate and
contingency mitigation sites because the sites contain characteristics which increase the probability of
wetland mitigation success... All of the sites are currently agricultural fields that have been ditched or
drained, and the majority of the 806 acres of mitigation contain hydric soils, which indicates that the site
previously functioned as a wetland.
The mitigation sites will meet the 2:1 replacement goal by providing 806 acres of wetland
restoration/creation, combined with over 300 acres of wetland preservation, and over 700 acres of upland
restoration and preservation. The majority of the wetland mitigation sites will include restoration and
preservation of riparian buffer areas adjacent to streams and rivers. Also, stream restoration will be
incorporated into the final design of several of the wetland mitigation sites.
The mitigation sites provide connections with existing forested wetland systems, thereby forming
extensive ecosystem complexes consisting of a variety of wetland, riverine, and forested upland habitats.
Over half of the mitigation sites are larger than 150 acres, and 1:1 acreage compensation can be
accomplished with just three sites. The smallest site includes 10 acres of wetland restoration/creation, but
its total mitigation project area is 42 acres, and the site is hydrologically connected to other mitigation
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EXECUTIVE SUMMARY
sites via a small stream/ditch. The largest site includes 195 acres of wetland restoration/creation in an
overall mitigation project area of 380 acres.
KING WILLIAM RESERVOIR PROJECT
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Requirements for Compensatory Mitigation
Following permit issuance, the RRWSG will complete a detailed final mitigation plan to include final
design plans and specifications for the mitigation sites, which must be submitted to the Corps and VDEQ
for approval prior to mitigation site construction. Specific requirements for the final plan were developed
in coordination with the interagency mitigation team and follow the "Draft Recommendations for
Compensatory Wetland Mitigation" jointly developed by the Corps and VDEQ (July 2003). The specific
requirements include: requirements for final design plans and specifications; success criteria; potential
permit conditions related to construction; monitoring; bonding; and restrictive language for protection in
perpetuity. The requirements are intended to guide development and implementation of site-specific
wetland mitigation plans following permit issuance. The requirements may be modified on a site-by-site
basis according to information provided during final mitigation site design (to account for varying success
criteria), and are worded to allow flexibility while maintaining oversight by the Corps and VDEQ.
Successful implementation of the mitigation requirements and conditions should guarantee success of the
mitigation sites.
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EXECUTIVE SUMMARY
Cultural Resources within the Mitigation Sites
Pursuant to 36 CFR Part 800, Protection of Historic Properties, regulations implementing Section 106 of
the National Historic Preservation Act of 1966, as amended, 16 U.S.C. 470f, and 33 CFR Part 325,
Appendix C, Processing of Department of the Army Permits: Procedures for Protection of Historic
Places, the Corps is required to take into account the effects of federally permitted undertakings on
properties included in or eligible for inclusion in the National Register of Historic Places. As part of this
process, the Corps is required to consult with the State Historic Preservation Officer (SHPO).
With respect to the King William Reservoir project, the City of Newport News (City), the Corps, the
VDHR, the Advisory Council on Historic Preservation (ACHP), and other interested parties, will sign a
programmatic agreement (PA) to serve as the basis for satisfying the requirements of Section 106. The
programmatic agreement will provide a framework for the identification, evaluation, and mitigation of
adverse effects to all significant historic properties that will be impacted by the proposed reservoir
project, to include the mitigation sites.
Compliance with USAGE Regulatory Guidance Letter 02-2
The Corps recently developed supplemental regulatory guidance on compensatory mitigation projects for
aquatic resource impacts under the Corps regulatory guidance program pursuant to Section 404 of the
Clean Water Act and Section 10 of the Rivers and Harbors Act of 1899. The regulatory guidance letter
(RGL 02-2) published on December 24, 2002 clarifies and supports the national policy for "no net loss"
of wetlands. It does not modify existing mitigation policies, or regulatory guidance such as the 1990
MOA, but provides guidance by which permittees must provide appropriate and practicable mitigation for
authorized impacts to aquatic resources.
The RRWSG has recognized these points of clarification in RGL 02-2 and has incorporated these
guidelines by developing a watershed approach with a variety of supporting elements. These elements
include wetland restoration, wetland establishment, wetland preservation, upland buffer preservation,
upland restoration, stream buffer restoration and preservation, and large-scale natural system riparian
preservation. Additionally, a functional assessment involving "priority functions" as agreed upon by the
mitigation team for the project was used to evaluate the goal of no net loss of wetland functions.
DOWNSTREAM WETLANDS
With VDEQ-mandated median monthly flow releases, the substantially reduced King William Reservoir
(i.e., Dam Site IV) will protect the downstream Cohoke Creek ecosystem from reasonably foreseeable
adverse effects. The following key points support this conclusion:
The monthly varying release requirements would preserve at least 73 percent of estimated
average flow at Dam Site IV, at least 85 percent of average flow into Cohoke Millpond, maintain
seasonality associated with pre-project flows, and would even preserve more streamflow than
would naturally occur during drought conditions.
Even under 2040 to 2050 conditions, when RRWSG demands are projected to require full use of
King William Reservoir safe yield, the reservoir would still be full in 59 percent of the simulated
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EXECUTIVE SUMMARY
months, thereby providing frequent opportunities for storm events to cause high flow pulses in
Cohoke Creek. The reservoir would be full even higher percentages of time during the decades
before the reservoir's full capacity is needed.
An additional 7.4 square miles of watershed area draining to Cohoke Creek between Dam Site IV
and the Cohoke Millpond dam would provide runoff and sediment loading that would
substantially augment downstream flows and aid in wetland maintenance beyond the protection
afforded by reservoir releases.
The RRWSG has made a proposal for downstream corridor preservation that will protect
wetlands and surrounding uplands in a continuous wildlife preservation corridor between Dam
Site IV and Cohoke Millpond (see Section 5). Under the terms of agreement between the
applicant and King William County, the host jurisdiction, the County has a right to pursue a
future dam downstream of the currently proposed dam site (KWR-FV). Although this right is
preserved in the host agreement, the RRWSG is unaware of any plans to develop a downstream
impoundment on Cohoke Creek. King William County is slated to receive an allotment of the
reservoir's safe yield to meet their projected water needs; therefore, if expansion of the King
William Reservoir is pursued, it would occur well in the future. Construction of another dam
would also require permit approval from the Corps and the State.
A high level of downstream protection will be provided with this reservoir project, and certainly
more than typically required for other such projects in the Mid-Atlantic region.
STREAM AND RIPARIAN BUFFER MITIGATION COMPONENT
Approximately 14.5 miles of first order stream, 3 miles of second order stream and 3.5 miles of third
order stream (a total of 21 miles of streams) will be flooded by the reservoir. Stream and riparian corridor
restoration, enhancement and preservation are included in the reservoir mitigation plan to offset these
losses. Based on mitigation ratios outlined in the joint state and federal agency stream mitigation
guidelines published by the Corps' Wilmington District (Corps, 2003), the project has back calculated
mile-credits using the following ratios: 1:1 for restoration, 1.5:1 for enhancement, and 2.5:1 for
preservation. According to these ratios the stream and riparian corridor mitigation component provides
21 mile-credits of stream and riparian corridor mitigation with a total amount of restoration, enhancement
and preservation of 36.4 miles. The totals for each mitigation component are contained in the following
table.
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EXECUTIVE SUMMARY
KING WILLIAM RESERVOIR PROJECT
Stream and Riparian Corridor
Order
First
Second
Third
Fourth
Fifth
Totals
Restoration
3.6
0.0
0.8
0
0
4.4
Enhancement
11.0
2.4
0.9
0.0
0.0
14.3
Preservation
7.9
3.0
6.1
0.0
0.8
17.7
Total
22.5
5.4
7.7
0.0
0.8
36.4
Restoration for the purposes of this project generally includes restoring the appropriate geomorphic
dimension (cross-section), pattern (sinuosity), and profile (channel slopes) to a stream. This includes new
channel construction, etc. In most cases this would include some degree of riparian preservation.
Enhancement includes stabilization of streambanks through sloping to restore the appropriate dimension
and vegetating a riparian zone (typically 50 feet from the bankfull elevation) that is protected from
livestock by fencing, and construction of structures for the primary purpose of stream bank stabilization.
In most cases this would include some degree of riparian preservation. Preservation includes placing a
restrictive covenant or deed restriction on a riparian buffer, typically, 50 feet from the bankfull elevation
on either side of the channel.
HABITAT MITIGATION COMPONENT
The mitigation plan incorporates several elements to compensate for the loss of wildlife habitat from the
reservoir project.
Wetlands
The wetland restoration/creation element will offset the loss of the 403 acres of vegetated wetlands in the
reservoir pool, at a ratio of 2 acres for every acre lost (2:1 acreage compensation). Therefore, the plan
will restore/create 806 acres of wetlands, and it includes a minimum of 1:1 compensation for each
affected vegetation cover type. Approximately 315 acres of wetlands adjacent to the wetland
compensation sites will be preserved in perpetuity. This will prevent any future logging, draining, or
other activity in these wetlands, which could result in a conversion of the habitat from forested to scrub-
shrub or emergent communities. Preservation of wetlands adjacent to mitigation sites also will ensure
that the created/restored wetlands will be provided additional protection, thus increasing the likelihood of
successful establishment.
Reservoir
The project will create a 1,526-acre reservoir providing valuable open water and shoreline habitat.
Approximately 1,251 acres of deepwater habitat will be created and approximately 322 acres of valuable
shoreline wetlands and shallow water habitat would potentially develop between the 90 and 97-foot
contours around the 77-mile shoreline. A fisheries management program will be implemented to include
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supplementary stocking of forage and game species to augment natural populations. The reservoir will
also provide extensive recreational opportunities.
Streams
Stream corridors targeted for restoration and preservation have historically incurred degradation resulting
from agricultural activities and development or are under threat from potential development. Restoration
may involve the removal of livestock from the streams and stream banks by installing fencing. This will
allow riparian vegetation to become reestablished and provide a mechanism for sediment and nutrient
removal from runoff. The restoration effort will increase the value of habitat for fish and invertebrates
currently impacted by agricultural activities and land development.
Upland Restoration and Preservation
Approximately 3,223 acres of upland habitat will be restored, restricted, and/or preserved as part of the
mitigation plan. This includes 1,900 acres of upland forest that will serve as a buffer around the reservoir.
The buffer consists of a 100-foot preservation setback (1,300 acres) from the reservoir pool area that will
be protected in perpetuity and an additional 100-foot construction setback (600 acres) in which
development will be strictly limited. In addition, approximately 700 acres of upland habitat will be
restored and/or preserved around the proposed wetland mitigation sites and 620 acres of uplands will be
preserved downstream of the dam.
Threatened and Endangered Species
No endangered species are affected by the proposed project. The reservoir will benefit Bald Eagles by
providing valuable new open water habitat and by preserving trees around the shoreline that will provide
perching, roosting and nesting habitat.
Although there should be no direct impacts to the federally-threatened Sensitive Joint-vetch from
construction or operation of the intake, pre- and post-construction monitoring will be conducted to
identify and ameliorate potential disturbances to this species.
Although no federally-threatened Small Whorled Pogonia plants will be impacted by the proposed
project, the RRWSG is offering to provide substantial mitigation measures to offset impacts to potential
small whorled pogonia habitat. The RRWSG, in coordination with the USFWS, has proposed to preserve
an existing colony that is under threat of destruction. No federal or state protection is currently afforded
to this colony.
Wetland Education
Education opportunities represent a valuable benefit of wetlands. The RRWSG has offered to support a
proposal, developed during the Section 106 of the National Historic Preservation Act consultation process
with the Pamunkey and Mattaponi Indian Tribes, the Corps and other agencies, to provide financial or
other support for wetland and/or environmental education.
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FUNCTIONAL ASSESSMENT
A functional assessment was performed to ensure that the King Williams Reservoir project and associated
reservoir mitigation plan would cause no overall net loss of wetland values and functions. The applicant
used current and localized data, to the extent practicable, to complete the functional evaluations, and
modified the assessments based on Corps review and comments. The functional assessments focused on
four priority functions:
Ecosystem support as quantified by total net primary productivity (TNPP).
Water quality as quantified by sediment retention and nutrient assimilation.
Habitat functions as evaluated by Habitat Evaluation Procedures (HEP).
Landscape interspersion and connectivity evaluated by landscape position.
The assessment of changes in TNPP demonstrated that conversion of a large fraction of the Cohoke Creek
watershed to a reservoir, together with establishment of wetlands at mitigation sites, would result in an
increase in aquatic net primary productivity. The water quality assessment concluded that the reservoir
and mitigation sites would result in a net increase in sediment retention and nutrient assimilation, both by
conversion of agricultural land uses to forest and wetlands, and by retention/assimilation of pollutants in
the reservoir itself. Application of the habitat evaluation procedures (HEP) demonstrated that the
mitigation components would actually provide habitat gains for all wetland dependent species, including
the beaver, mink, great blue heron, wood duck, red-spotted newt, and yellowthroat. The plan provides
some level of compensation for each evaluated species.
The analysis of landscape interspersion and connectedness demonstrated that the King William Reservoir
project and its accompanying mitigation will involve an exchange of 403 acres of wetlands that are
disconnected from the downstream watershed by the Cohoke Millpond for 806 acres of wetlands that are
all directly connected to tributaries of the Bay. From an ecological standpoint, the landscape interspersion
and connectivity functions would thereby be improved.
ASSURANCES FOR MITIGATION SUCCESS
The RRWSG has made every effort to minimize the risk involved with the mitigation proposals. Critical
elements of the plan must be reviewed and agreed upon by the Corps and its advisory agencies before
proceeding. Similar requirements are already included in the Virginia Water Protection Permit, to include
a requirement for public review of the final mitigation plan and plan approval by VDEQ prior to
mitigation site construction. Most of the mitigation will be in place and subject to review and approval
prior to the impacts occurring, and the RRWSG has allocated approximately 300 acres of contingency
sites in the event that some failure occurs. To further ensure success, enforceable provisions of the
Virginia Water Protection Permit specifically require success criteria, a monitoring program and
contingency provisions to ensure that the entire mitigation plan is successfully established. The RRWSG
has committed to monitoring the wetland compensation sites over a twenty-year period. This lengthy
monitoring commitment is unprecedented and demonstrates the RRWSG's commitment to successful
mitigation implementation.
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EXECUTIVE SUMMARY
A real estate instrument will be recorded in the chain of title that will require the preservation of the
mitigation site (including wetlands) on the property in its post-construction/post-restoration condition in
perpetuity. The RRWSG will secure appropriate financial assurances guaranteeing that the approved
mitigation will be completed, and will be conditioned upon performance of the required mitigation and all
required monitoring.
The final site-specific requirements for the compensatory mitigation sites, to include monitoring, success
criteria, perpetual easements, and financial assurances will require approval by the Corps/VDEQ prior to
mitigation site construction.
\ I
MITIGATION COMMITMENTS
The RRWSG is committed to successful implementation of the reservoir mitigation plan and has
identified specific conditions that will be adhered to following permit issuance to ensure plan success.
CONCLUSION
The reservoir mitigation plan represents the culmination of a lengthy, complicated process in which
numerous federal and state agency representatives and wetland mitigation experts provided detailed
analysis and review at virtually every step of its formation. The RRWSG has worked diligently and in
good faith to solicit consensus and agreement from the federal advisory agencies in completion of the
mitigation plan.
As mandated by the February 1990 "Memorandum of Agreement Between the Environmental Protection
Agency and the Department of the Army Concerning the Determination of Mitigation under the Clean
Water Act Section 404 (b)(l) Guidelines" (Joint MOA), the King William Reservoir mitigation plan
identifies appropriate and practicable methods and strategies that will be employed to offset impacts to
aquatic resources within the reservoir project area. Successful implementation of the compensatory
mitigation components will offset the adverse impacts of the proposed fill discharges to wetlands, and
provide compensation for other impacts within the project area. As stated in the NAD Corps September
2002 Decision Memorandum regarding the RRWSG's proposed mitigation plan, "successful
implementation of compensatory mitigation resulting in no net loss of wetland functions and values
would satisfactorily offset the adverse impacts of the proposed fill discharge." The 2:1 compensation will
ensure that the project's wetland impacts will be more than offset by the mitigation plan and provides full
wetland functional replacement by offsetting the "lag time: for establishment of fully functioning
wetlands. The 2:1 compensation provided by the mitigation plan will also achieve full functional
replacement in a shorter time frame and allows for less than designed final function (per acre) in the event
of a partial failure. The following table provides a summary of all the mitigation elements contained in
this reservoir mitigation plan.
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Mitigation Components
Wetland Restoration/Creation
> Provides 2:1 Compensation
> Provides full wetland functional replacement
> Offsets "lag time" for wetland establishment
Stream Corridor Restoration/Preservation
> Fully compensates for 21 miles of impact
Wetland Preservation
Upland Restoration
Upland Preservation
Downstream Preservation Areas '
Deep Water Habitat
Shoreline Wetlands and Shallow Water Habitat
Wetland Education Opportunities
Total Acreage
TOTAL
Wetlands
(Acres)
806
315
186
322
1,629
Uplands
(Acres)
637
1,966
620
3,223
Open
Water
(Acres)
1,251
1,251
Other Elements
36.4
6.4 stream miles
Coordination w/
Pamunkey and
Mattaponi Indian Tribes
6,103 Acres
1 Under the terms of agreement between the applicant and King William County, the host jurisdiction, the County has a right to pursue a
future dam downstream of the currently proposed dam site (KWR-IV); however, the RRWSG is unaware of any plans to develop a
downstream impoundment on Cohoke Creek.
The interagency mitigation team, including representatives of the Corps, USEPA, USFWS, and the
VDEQ, was intimately involved in the process of mitigation site selection. Recently, the VDHR joined
the mitigation team to ensure compliance with Section 106 of the National Historic Preservation Act. The
RRWSG has identified over 806 acres of potential wetland restoration and creation areas within the
Chesapeake Bay watershed that can be used to offset the loss of 403 acres of vegetated wetlands within
the reservoir pool area at a 2:1 compensation ratio. The RRWSG has also identified approximately 300
acres of contingency sites that have been acknowledged by the mitigation team as acceptable mitigation.
Recognizing that the selected primary mitigation sites and contingency sites were chosen for their
excellent characteristics and their high probability for wetlands establishment success, any combination of
these sites (providing 2:1 compensation or 806 acres) would provide full wetland functional replacement.
The RRWSG is also committed to a program of stream restoration, enhancement, and preservation to
offset the losses associated with flooding of approximately 21 miles of nontidal, intermittent and
perennial streams within the reservoir pool area, and to offset the loss of riparian habitat within the project
area. Streams will be restored, enhanced and preserved at appropriate credit ratios to provide 21 mile
credits of stream and riparian corridor mitigation. The stream mitigation component effort will increase
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EXECUTIVE SUMMARY
the value of habitat for fish and wildlife currently impacted by agricultural activities and land
development.
The wetland mitigation plan does not replicate the Cohoke Creek stream valley system; however, the
mitigation components will provide full wetland functional replacement. When combined with the
reservoir, buffer, and downstream preservation area, the plan encompasses more than 6,100 acres of
preserved land, water and wetlands, which will be a significant contribution to the Commonwealth of
Virginia's efforts to restore and preserve the Chesapeake Bay and its tributaries.
The Corps has acknowledged that the reservoir and mitigation plan developed by the RRWSG would
provide environmental benefits to the Chesapeake Bay, an aquatic resource of genuine national
importance. As stated in the September 2002 Corps Decision Memorandum for the project, "Some
benefits are expected to accrue from creation of the reservoir, successful implementation of wetland
mitigation and land preservation and management plans. The Chesapeake Bay watershed may be better
maintained in the long-term, since several thousand acres of land will be preserved from more intense
development. The thousands of acres of land which would be preserved or ecologically improved include
the reservoir, the reservoir buffer zones and the wetlands restoration areas, providing long-term benefit to
the adjacent area and the Chesapeake Bay."
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SECTION 1.0
MAlJOOUVi
PIRNIE
PROCESS AND HISTORY OF THE
KING WILLIAM RESERVOIR
MITIGATION PLAN
1.1 INTRODUCTION
This section details the process that the Regional Raw Water Study Group (RRWSG) has followed in
developing the King William Reservoir Mitigation Plan. The process is presented below in chronological
fashion and describes key documents, approvals, and interagency participation associated with Plan
development.
The Reservoir Mitigation Plan is the culmination of more than ten years of interagency coordination and
mitigation planning. Many drafts of the mitigation plan were developed and revised based on agency
comments. Key milestones of this process were as follows:
Feb. 1994: DEIS with Conceptual Wetland Mitigation Plan
May 1994: Field Delineation of Wetlands Conducted
Nov. 1995: Habitat Evaluation Procedures (HEP) Study Initiated
Dec. 1995: Supplement to DEIS with Conceptual Mitigation Plan
" Aug. 1996: Conceptual Mitigation Plan for VDEQ
Jan. 1997: FEIS with 1996 Conceptual Mitigation Plan for VDEQ
July 1997: Draft Wetland Mitigation Pilot Study
Sep. 1997: Wetland Mitigation Pilot Study
Oct. 1997: Reservoir Fringe Study
Oct. 1997: Draft Wetland Mitigation Plan
Dec. 1997: VDEQ Virginia Water Protection Permit
June 1998: Draft Habitat Evaluation Procedures (HEP) Study
ป July 1998: Working Draft Mitigation Plan
Feb. 1999: Final Revised Draft Wetland Mitigation Plan
Feb.1999: Final Habitat Evaluation Procedures (HEP) Study
April 1999: Draft Fish and Wildlife Mitigation Plan
May 1999: Final Fish and Wildlife Mitigation Plan
May 1999: Final Wetland Mitigation Plan
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PROCESS AND HISTORY OF THE
KING WILLIAM RESERVOIR
MITIGATION PLAN
1.2 STATE AND FEDERAL PERMIT PROCESS AND THE RRWSG's EFFORTS
Since initial project planning efforts in 1989, the RRWSG has adhered to the Section 401 and Section 404
permit programs, National Environmental Policy Act (NEPA) regulations, and guidance from the Virginia
Department of Environmental Quality (VDEQ), the U.S. Army Corps of Engineers (Corps), the U.S.
Environmental Protection Agency (USEPA), the U.S. Fish and Wildlife Service (USFWS), and other
federal and state agencies.
As a first step, the RRWSG undertook formal NEPA "scoping" to identify the issues for discussion in an
EIS. More than 30 alternatives were identified and reviewed for availability, practicability, and for their
environmental effects, all of which involved the federal and Virginia regulatory agencies. From these
alternatives, the King William Reservoir Project emerged as the RRWSG's preferred project.
1.3 REGULATORY INVOLVEMENT
In an effort to develop a mitigation plan that was acceptable by the reviewing regulatory agencies, the
RRWSG spearheaded development of a Mitigation Team comprised of representatives of the USEPA,
USFWS, VDEQ and RRWSG. The Mitigation Team identified objectives for plan development. Other
state and federal agencies, academic wildlife and wetland experts, local Indian Tribes, and special interest
groups were often invited to participate in the Mitigation Team meetings. For example, initial Mitigation
Team meetings also included representatives of the Virginia Department of Conservation and Recreation,
Virginia Department of Game and Inland Fisheries (VDGIF), Virginia Institute of Marine Science, Nature
Conservancy, Chesapeake Bay Foundation, Sierra Club, and Environmental Concern, Inc. Mitigation
Team meetings included:
February 22, 1995
August 2, 1995
November 17, 1995
February 19, 1997
February 20, 1997
April 17, 1997
July 10, 1997
July 16, 1997
August 28, 1997
November 13, 1997
February 23, 1998
April 6, 1998
First Wetland Mitigation Workshop
Second Wetland Mitigation Workshop
Mitigation Field Work with USFWS
Mitigation Team Field Meeting
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team/HEP Team Meeting
Mitigation Team Meeting
Mitigation Team Field Meeting
Mitigation Team Field Meeting
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June 25, 1998
June 26, 1998
August 25, 1998
August 26, 1998
September 11,1998
April 7, 1999
April 8, 1999
April 10, 2003
August 4-7, 2003
August 8, 2003
October 9, 2003
November 3, 2003
November 14, 2003
February 26, 2004
June 2, 2004
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team Meeting
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team Meeting
Mitigation Team Field Meetings
Mitigation Team Meeting
Mitigation Team Meeting
Mitigation Team Conference Call
Mitigation Team Field Meeting
Mitigation Team Meeting
Mitigation Team Meeting
Note: This list excludes additional HEP Team meetings and agency field investigations for the reservoir
fringe evaluation
1.4 DRAFT EIS (FEBRUARY 1994)
When the RRWSG filed its first permit application in July 1993, the application described the
configuration of the King William Reservoir Project now known as "KWR-I". Based on aerial
interpretation and limited ground reconnaissance, the conceptual wetland mitigation plan provided in the
DEIS called for the creation/restoration of 452 acres of wetlands to offset impacts at a 1:1 ratio. The
majority of the mitigation was planned within the Cohoke Creek watershed, and consisted of wetland
development along the perimeter of the proposed reservoir, in the reclaimed borrow area to be utilized to
construct the dam, in various small impoundments in the headwaters of the small tributaries to Cohoke
Creek, and in prior converted croplands found in the watershed. Two constructed wetlands located 4,000
feet west of the proposed dam site were also proposed. The project goal was "no net loss" of wetland
function or acreage.
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1.5 SUPPLEMENT TO THE DEIS (DECEMBER 1995)
Field delineation of wetlands was conducted in May 1994 and identified 653 acres of wetlands within the
KWR-I project area. In response to comments on the Draft EIS, the RRWSG relocated the proposed dam
site approximately 2,900 feet upstream to dam site "KWR-II" to minimize wetland impacts.
Mitigation Team Directive: Dam site moved 2,900 feet upstream (KWR;II)
to minimize wetland impacts. . iซ ';! ~:: ' "';;*-- , "
During the first Mitigation Team meeting on February 22, 1995, the agencies requested that the
mitigation occur on-site, or within the Cohoke Creek basin, to the extent practicable.
'-Mitigation "Team Directive! On-site
" "'" '
The second Mitigation Team meeting on August 2, 1995 identified the need for a Habitat Evaluation
Procedures (HEP) study and Evaluation for Planned Wetlands to provide functional assessments.
Riparian habitat restoration was also discussed as a mitigation requirement. No conclusion was reached
regarding appropriate mitigation ratios.
ationV^e^'' to include large, -contiguousfareas; with
,, < . - - / ''',iv*if*3ฃ/AฃVo- '->'. ^'-u% *ฐ*? ,'*':, - '' ^"'- *!'{ฃ, \>-
associated upland/Wetland habitats^ terrestrial"; mitigation required;'wetland ftirictional
evaliiatipns required (EPW* HEP), stream^tigation required;*';2iIf replacement for PFO
i^acSa^-rfbr^faaa^ill for ^^W W&ฃ '. ^
The initial HEP Team meeting, attended by representatives of the Corps, USEPA, USFWS, VDEQ,
RRWSG, and a wildlife expert from Virginia Tech, was held on November 21, 1995 to discuss objectives
and methodology for the HEP study.
The conceptual mitigation plan presented in the Supplement to the DEIS was designed so that the project
goal of "no net loss" of wetland functions or acreage would be attained. Mitigation strategies were
identified to offset impacts to 524 acres of vegetated wetlands within the KWR-II pool area.
The plan consisted of restoration of prior converted croplands and farmed wetlands within the reservoir
watershed, borrow area wetland construction, and headwater wetland construction. Prior converted
cropland restoration within the Pamunkey and Mattaponi River Basins was also identified as a mitigation
objective.
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The HEP Team continued to meet regularly to identify study objectives. Field studies on the proposed
pool area and reservoir buffer were completed in the summer of 1996 to determine the current habitat
value for selected fish and wildlife species. Once impacts to the evaluation species from reservoir
construction were quantified over time, habitat benefits from the reservoir, reservoir buffer and mitigation
sites were quantified. The results of the HEP study would be used to determine what would be necessary
for full replacement of habitat value that will be lost due to reservoir construction.
1.6 CONCEPTUAL MITIGATION PLAN FOR THE DEQ (AUGUST 1996)
Agency comments on the Supplement encouraged the RRWSG to investigate additional mitigation sites
in the Pamunkey and Mattaponi River basins within King William County and portions of New Kent and
Hanover Counties. In addition to wetland mitigation, the agencies requested that the mitigation plan
include measures to offset impacts to streams and upland habitat within the pool area, pipeline impacts,
and impacts related to river withdrawals (i.e., anadromous fish, threatened and endangered species).
Federal Agency Directives: Downsize KWR again,jsearch for off-site mitigation areas in
the Mattaponi and Pamunkey River basins. RRWSG commits to include anadromous fish
passage restoration, and threatened and endangered species mitigation. ;
Following a request from the RRWSG regarding mitigation requirements, VDEQ issued a letter dated
December 8, 1995 providing minimum requirements of a "conceptual" wetland mitigation plari for the
King William Reservoir Project. In addition to general site information, VDEQ requested: a description
of sources of hydrology for restored/constructed wetlands; description of construction measures or
devices to restore and maintain hydrology; a functional assessment of the wetland functions performed by
the mitigation sites; water budget during a dry year for constructed wetlands relying on the normal pool
elevation for hydrology and an analysis of the frequency of occurrence that the normal pool elevation
would not be a contributing factor to wetland hydrology. VDEQ also included the following
requirements:
A conceptual monitoring plan.
Description of remedial actions taken in case of failure to establish the proposed wetlands.
A qualitative and quantitative functional assessment of the mitigation plan that includes a
description of functions that are created over and above those that are lost, as well as functions
that are not replaced..
Description of deed restrictions, conservation easements, preservation agreements, or title
transfers, as well as management measures.
The Corps' Norfolk District policy on replacement of wetland types would have required the RRWSG to
mitigate at approximately 1.7:1 for wetland impacts. However, as suggested by the Corps, the RRWSG
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offered to go beyond the Corps' policy and commit to a 2:1 wetland restoration and creation goal in an
attempt to facilitate the permitting process.
Mitigation Team Directive: KRWSG commits to a 2:1 wetlaiad restoration/creation goal
going beyond Corps! Norfolk District Branch Mitigation Guidance.
The August 1996 Conceptual Mitigation Plan wetland restoration/creation component alone provided
more than 2:1 compensation for project impacts associated with KWR-II. A functional assessment, using
the EPW procedure, was made of the existing Cohoke Creek wetlands and the proposed wetland
restoration/creation areas on the mitigation sites. The EPW procedure demonstrated that the 2:1 level of
compensation would provide a substantial net gain in wetland functional benefits. Priority was given to
identifying potential wetland restoration sites, due to a high level of restoration success. Wetland creation
in the dam borrow area and sand and gravel-mined areas were given second priority due to ample
hydrologic inputs. The plan also identified approximately 322 acres of aquatic fringe habitat that would
be created around the perimeter of the reservoir.
In addition to the wetland restoration/creation sites, the conceptual plan identified several other mitigation
components that exceeded the DEQ's minimum requirements for a "conceptual" wetland mitigation plan.
Large tracts of uplands would be restored and/or preserved in perpetuity around the reservoir and
mitigation areas, potential fish passage restoration sites were identified, improvements to the Mattaponi or
Pamunkey Indian Reservation fish hatcheries were proposed, mitigation for impacts to threatened and
endangered species were evaluated, and a large stream corridor preservation/enhancement project was
proposed.
1.7 FINAL EIS (JANUARY 1997)
The RRWSG continued to minimize wetland impacts by developing a dam site "KWR-IV" proposal,
which reduced the gross impacts to wetlands and open waters to 437 acres (392.5 and 44.5 acres,
respectively), saving 206 acres from the original KWR-I proposal. This further minimization came at a
significant cost, however, since moving the dam site another 1.1 miles upstream (1.7 miles above dam site
KWR-I) reduced the total storage by 42%, from 21 to 12 billion gallons.
Mitigation Team Directive: Dam* site moved anomef 1.1 miles; upstream; (1.7 miles
above darn site KWR-1^ reducing wetland. impacte by'206 acres. > ;; ?' ;
The August 1996 King William Reservoir Project Conceptual Mitigation Plan for the Virginia
Department of Environmental Quality (Malcolm Pirnie, 1996) is included in Volume II of the FEIS Main
Report. Although the preferred project alternative within the FEIS was the KWR-IV proposal, the
mitigation plan addressed impacts associated with the KWR-II project. The conceptual mitigation plan
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demonstrated that the project's wetland impacts would be more than offset by compensatory mitigation
projects.
1.8 WETLAND MITIGATION PILOT STUDY (SEPTEMBER 1997)
Following publication of the FEIS, the RRWSG continued to actively facilitate Mitigation Team
involvement in site selection and plan development. The Mitigation Team conducted numerous field
investigations of potential mitigation sites. Following each field visit, comments were solicited from the
Mitigation Team members to guide development of the conceptual plan.
During the April 17, 1997 Mitigation Team meeting, the level of detail needed for the federal permit was
discussed with regard to the mitigation plan. The Corps stated that final design, to include grading and
planting plans, would not be required for the federal permit.
Corps ^Norfolk District Directive: Final design of the wetland mitigation sites, to include
grading and planting plans, would not be required to obtain the federal permit.;.
Malcolm Pirnie was directed to identify potential mitigation sites based on 1:1 replacement of hydrologic
regime. The agencies agreed that preservation could be used as a last resort to meet the 2:1 requirements.
The Team concurred that efforts to identify mitigation sites could extend into the headwaters of the
Pamunkey and Mattaponi Rivers.
Mitigation Team Directives: Provide 1:1 wetland replacement by hydrologic:regime;
preservation could be used to meet 2:1 acreage requirement; search area for mitigation sites =
extended into the Mattaponi and Pamunkey River headwaters! Jtp ; :; ,
The Team concurred that impacts to streams within the project area should be mitigated at a 1:1 ratio
(stream order to stream order) by combining restoration, preservation, and enhancement of streams within
the Pamunkey and Mattaponi watersheds. Once these options were exhausted, the RRWSG could search
in adjacent watersheds for riparian restoration sites or identify preservation areas on the Pamunkey or
Mattaponi Rivers threatened by development. Mitigation for impacts to anadromous fish was also
discussed.
Mitigation Team Directives: Mitigate for stream impacts at a 1:1 ratio by stream order
impacted, to include preservation, restoration, and enhancement; mitigate for anadromous
fishimpacts : ' " -. '"' v.( v^V-.v-wV'-' ' :: ^-i -4;K;;;;-*:".^ ;;'-
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The Corps stated that a final design plan would not be required for the federal permit; however, a debate
over what would be required in the Final Plan led to an agreement by the Team that a Pilot Study should
be conducted for one of the proposed mitigation sites. The Pilot Study would include hydrologic data, to
include water budgets using TR-55, soil data, cross-section information, planting schemes, monitoring
plan, soil amendments, and a conceptual design. The use of berms or deep excavation was discouraged.
Mitigation Team Directive: Conduct a;Wetland Mitigation Pilot Concept Design Study.
The Final Pilot Study was developed in response to July 29, 1997 agency comments on the June 1997
draft Pilot Study. Additional information requested by the agencies that was incorporated into the plan
included:
Narrative description of the site to include wetland acreages, hydrologic regimes, and anticipated
wetland functions to be restored at the mitigation site
Description of site history and past land use
Wetland delineation
Discussion of sustaining long-term hydrology
Water budgets for dry and wet years in addition to normal years
Frequency of flooding for sites adjacent to rivers
Monitoring plan to include performance criteria as identified in the mitigation guidelines used by
the Norfolk District
ป Contingency measures
1.9 RESERVOIR FRINGE STUDY (OCTOBER 1997)
During the April 17, 1997 Mitigation Team Meeting, the agencies requested additional information
regarding the development of fringe wetlands around the perimeter of the reservoir.
Mitigation Team Directive: Fringe Study was conducted, to-'include numerous field
investigations, with agency involvement^ Study completed^in October 1997 concluded mat
322 acres of vegetated wetlands' and shallow water Habitat would develop around the
Reservoir shoreline. . > ;;' ' ' ' "y'j'V.-"'-" ','T '.. ' '- ;,
The Reservoir Fringe Study was conducted in response to agency concerns regarding the likelihood and
sustainability of fringe wetland establishment around the reservoir perimeter. The study provided a
qualitative assessment of potential fringe wetland establishment along the perimeter of the King William
Reservoir based on a review of current development and habitat conditions at five regional reference
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reservoirs. Development conditions were established from surrounding land use patterns and factors
influencing local growth. Fringe wetland habitat conditions were developed from factors such as depth of
water, slope, aspect, soil, fetch and shading. Based upon those conditions assessed as favorable to the
establishment of fringe wetlands, it was estimated that 121 acres of vegetated fringe emergent wetlands
and more than 80 acres of submerged vegetated wetlands would potentially establish in the King William
Reservoir littoral zone.
1.10 DRAFT WETLAND MITIGATION PLAN (OCTOBER 1997)
Identification of additional mitigation sites continued under the guidance of the Mitigation Team; and the
Pilot Study was used as a model for development of site information and conceptual design plans for
other mitigation sites. Specific criteria were established for identifying, evaluating, and selecting sites.
The first step included a broad elimination of specific regions with undesirable conditions including:
" Areas distant from the Pamunkey and Mattaponi Rivers.
* Urbanized areas.
Areas outside the York River Basin.
Areas requiring substantial excavation.
The second step of the site identification and selection process included the identification of favorable site
qualities and characteristics including:
Landowner willingness.
Sites containing hydric soils, extent of hydric soils and clayey subsoils.
Sand and gravel operations were regarded as viable sites due to available hydrology.
Existing access to mitigation sites.
Landscape position, preferably sites adjacent to river or tributary, or other naturally occurring
aquatic ecosystem.
High groundwater table.
Large areas of potential restoration/creation. ,
Sites possessing secondary water supply. I
Sites having minimal impact on cultural resources. *
The extensive site information and conceptual designs completed for selected mitigation sites were
compiled in the October 1997 Plan.
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Mitigation Team Directive: Complete evaluations for each mitigation site to level of
0 -' '!' ' "',,',' ' V - . *,' , , ; '",'?; ' '-, ,',.,-; .7,.;-.' ,'>.*.,'."?*"->
detail provided in, the Pilot Study. 4V .'> ' ,<
As stated above, plan components were established based on the requirements for the RRWSG's 1997
Pilot Study. Typically, the level of mitigation planning prior to receiving a permit involves preliminary
concept planning only. However, for this project, extensive planning, fieldwork, and design activities
were carried out to ensure a high probability of success.
The purpose of this plan was to supply sufficient information so that all members of the Mitigation Team
would be satisfied that the selected mitigation sites and proposed plans would have a reasonably high
probability of success. Comments received on the plan indicated that the level of detail was extensive.
1.11 VIRGINIA WATER PROTECTION PERMIT (VWP PERMIT No. 93-0902)
(DECEMBER 22,1997)
The VDEQ Virginia Water Protection (VWP) permit for the King William Reservoir Project identifies the
State requirements for completion and implementation of the wetland mitigation plan. In summary, these
requirements include creation or restoration of vegetated wetlands at a 2:1 level of compensation as well
as submittal of a detailed final plan for VDEQ approval prior to impacting wetlands in project area. The
plan must also establish success criteria, include a monitoring program, and include contingency
provisions.
1.12 WORKING DRAFT MITIGATION PLAN (JULY 1998)
Based on agency comments on the October 1997 plan and additional field investigations, one of the sites,
a large sand and gravel mined area, was dropped from the plan, other site designs were modified, and six
additional sites were identified for use as mitigation because they contain characteristics which increase
the probability of wetland success...
Mitigation Teani Directive; Eliminate King William Sand and Gravel Borroy Area Site;
(152 acres of wetland creation)^ |;
Extensive field investigations and detailed design plans were developed for new sites. The agencies
agreed to widen the search area to include potential wetland mitigation areas in the greater York River
drainage basin; therefore, portions of James City, York, Gloucester, and Mathews counties were
evaluated.
Mitigation Team Directive?Extend
York River drainage basin.' " T>
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Further investigations of potential stream mitigation sites were conducted. Several stream corridors in the
York River Basin were identified as potential candidates for restoration and preservation, to include a 21-
mile stream network in the headwaters of the Pamunkey River.
The July 1998 Mitigation Plan assured no net loss of wetland acreage resulting from the proposed project.
The plan included ten primary mitigation sites that provided 785 acres of wetland mitigation. The plan
also included contingency measures should there be a failure in the establishment of wetlands conceived
for the site(s). Other compensation strategies included in the mitigation plan included: fringe wetlands,
stream corridor restoration, enhancement, and preservation; stream channel opening; upland restoration
and preservation; wetland education; open water creation; and fish hatchery improvements.
yDEQ!Dirfective: RRWSG to look for opportunities to enhance and accelerate
fringe wetland development to satisfy acreage requirement. >
In addition to the EPW evaluation, functional assessments were conducted which included an evaluation
of the following functions provided by the wetlands within the project area and wetlands within the
compensation sites. During a June 26, 1998 meeting, the Mitigation Team described four priority
functions that should constitute the mitigation plan's goal to achieve "No net loss of function":
" Habitat Value Replacement (evaluated using HEP methodology).
Ecosystem Support/Primary Productivity.
Sediment Retention and Nutrient Assimilation.
Landscape Interspersion and Connectivity.
>Mitigatibii|reiam Directive: Evaluate four priority fuSctidhS that constitute the
:"-i*SW*ซt''t*"?B*!;<">*;!-.*'',;'v?v'-,iff W -T ' ซ,- > !i-s-">t;v3%^!ป-ป'ft>\;ปi"/ปป,,ซj^-;.,\,,,
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This wetland mitigation plan included compensation strategies for riverine habitat by providing
connection of stream corridors, enhancement, and preservation; restoring and preserving uplands; and
creating fringe wetlands associated with the reservoir. The KRWSG additionally supported a wetland
education program on the Pamunkey Indian Reservation. Successful implementation of the plan would
achieve the goal of compensating for all wetland losses by establishing fully functional, self-sustaining
wetland ecosystems.
1.13 FINAL HABITAT EVALUATION PROCEDURES REPORT (FEBRUARY 1999)
The HEP methodology is a detailed habitat assessment technique, developed by the FWS that can be used
to measure the habitat function of an area. The HEP Study was initiated in November 1995 and required
more than three years of intensive coordination to complete. Development of the HEP Report involved
extensive field investigations and numerous HEP Team meetings and correspondence.
The HEP was completed to provide a tool for mitigation plan habitat evaluation. The HEP Study
developed and evaluated various compensation strategies that would offset species habitat value lost in
the project area.
HEP Team Directive! Identify strategies for iulljTi-kind compensation*
The compensation strategies presented in the Study were presented as examples of compensation
strategies that could replace species habitat losses.
To determine whether the project impacts would be offset, the HEP methodology was applied to the
entire mitigation package, as summarized in the July 1998 Working Draft Mitigation Plan and the May
1999 Fish and Wildlife Mitigation Plan.
The wetland cover types within the reservoir pool area were reassessed during the HEP study. Although
the total acreage of wetland impacts did not change, the acreage of vegetated wetlands and open water
impacts changed from 392.5 and 44.5, respectively, to 403 acres of vegetated wetlands and 34 acres of
open water impacts.
1.14 FINAL FISH AND WILDLIFE MITIGATION PLAN (MAY 1999)
The primary purpose of this document was to describe the components of the RRWSG's Mitigation
Program developed to compensate for the loss of fish and wildlife habitat and other environmental
elements that may be impacted by the reservoir project. A draft of this document was published in April
1999; however, the RRWSG received no comments from the agencies. Details of the wetland mitigation
and stream corridor restoration were components presented in the May 1999 Final Wetland Mitigation
Plan.
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1.15 FINAL WETLAND MITIGATION PLAN (MAY 1999)
With efforts to identify other suitable mitigation sites within the York River Basin exhausted, the Corps
extended the search area for potential mitigation sites to include portions of the Rappahannock River
Basin.
Corps Norfolk District Directive: Extend mitigation site search area to include
portions offthe Rappahannock River Basin
Two additional sites were accepted by the interagency mitigation team as use for mitigation. . Extensive
field investigations and detailed design plans were developed for new sites and presented in the February
1999 Final Revised Draft Wetland Mitigation Plan. Following agency comments on the draft plan, the
dam borrow area site was dropped from the plan. During the April 8, 1999 Mitigation Team meeting, the
team discussed information needed for the final design (to include a vegetation planting scheme and
timetable for mitigation project development) that would be required following the Corps' permit
decision. The Corps stated that the Reservoir Borrow Area is not an acceptable mitigation site, but could
be used as a contingency site. The Corps also stated that the mitigation plan should identify another 160-
200 acres (20 to 25 % of the total acreage needed) that could be developed in the event of partial failures
of the primary mitigation sites.
Corpi;JVorfoIk District Directives: Eliminate Reservoir Borrow Area from mitigation
plan (62 ^cres of wetland creation); identify 160-200 acres of contingency mitigation
acreage;!; ?% '-. ';" '-^"^ ,".,'.?'; -. .'':"'!" > ' ' -. .. ;:
The RRWSG's May 1999 Wetland Mitigation Plan is the product of more than five years of detailed
cooperative investigations by an interagency mitigation team which included the RRWSG and its
consultants, the Corps, USFWS, USEPA, VDEQ, and others. More than 250 potential mitigation sites
were investigated and rejected for various reasons (i.e., minimum size requirements, isolation from
streams or existing wetlands, substantial excavation required, avoiding mature forested areas to prevent
loss of existing habitat, etc,). The interagency team agreed to the identification and use of the twelve sites
described in the May 1999 Plan because these sites contain characteristics which increase the probability
of wetland mitigation success, given proper final designs, review agency involvement, construction
oversight, monitoring, and remediation.
The May 1999 wetland mitigation plan includes restoration and creation of over 806 acres of wetlands,
more than double the 403 acres of vegetated wetlands in the footprint of the reservoir, and identifies
contingency sites that could be developed if any of the primary sites fail to develop according to specified
criteria. Non-wetland components of the mitigation plan include restoration and protection of 21 miles of
degraded stream corridors (a 1:1 offset for project impacts); fish passage restoration to a VDGIF priority
stream in the York River Basin; and financial support for the Pamunkey Indian tribe's wetland education
program and the Mattaponi and Pamunkey tribal fish hatcheries.
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1.16 RRWSG's RESERVOIR MITIGATION PLAN (DECEMBER 2003)
Following issuance of the Corps September 2002 "Decision Memorandum for King William Reservoir
Project, Norfolk District Application No. 93-0902-12", the RRWSG resumed coordination with an
interagency mitigation team, led by the Corps North Atlantic Division, to complete the mitigation plan.
Supplemental regulatory guidance issued by the Corps on compensatory mitigation projects for aquatic
resource impacts (RGL 02-02), published on December 24, 2002 provided guidance to the team for
updating and completing the mitigation plan. The RRWSG has recognized these points of clarification in
RGL 02-02 and has incorporated the guidance into their plan.
Corps Regulator^Guidance Letter 02-02:: Incorporate guidelines to provide appropriate
and practicable mitigation for authorized;impacts to aquatic resources.,;?;;; |i; *>
Site monitoring requirements, success criteria, and proposed language for financial agreements and
perpetual protection are included in this plan and were developed with guidance from the guidance team.
As reaffirmed to by the interagency team during the August 8, 2003 mitigation meeting, final design plans
and specifications for the wetland mitigation sites are not required prior to permit issuance. However, the
interagency team has developed requirements for final design plans and specifications to include
hydrologic monitoring, grading, soil amendments, and planting schemes.
The group of proposed mitigation sites has been modified since 1999 to address landowner issues, site
availability, and conceptual design concerns, following directives from the interagency team. The
interagency team has agreed to the identification and use of the candidate and contingency mitigation
sites included in the plan. The plan includes 11 mitigation sites that provide more than 806 acres of
wetland restoration/creation, approximately 315 acres of wetland preservation, and more than 700 acres
of upland restoration and preservation. Approximately 300 acres of wetland restoration/creation have
been identified as contingency sites should complications arise with the primary mitigation sites.
The plan also includes stream restoration, enhancement, and preservation to offset the losses associated
with flooding of approximately 21 miles of nontidal, intermittent and perennial streams within the
reservoir pool area, and to offset the loss of riparian habitat within the project area. The restoration effort
will increase the value of habitat for fish and wildlife currently impacted by agricultural activities and
land development.
The RRWSG is also committed to engaging in mitigation efforts to offset habitat impacts, mitigate for
potential impacts to endangered species, provide fish passage restoration, and offer wetland education
opportunities.
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1.17 SUMMARY OF RESERVOIR MITIGATION PLAN
The RRWSG's proposed 2:1 wetland mitigation ratio exceeds the typical state and federal mitigation
requirements (i.e., 2:1 for forested wetlands, 1.5:1 for scrub-shrub wetlands, and 1:1 for emergent
wetlands), by approximately 130 acres. Most of the mitigation sites are adjacent to surface watercourses
and extensive tracts of existing wetlands and uplands that will be protected and preserved in perpetuity.
A large majority of the wetland mitigation acreage (655 of the 806 acres in the primary mitigation sites,
or 81 percent) consists of restoration of prior converted wetlands, which historically has produced the
most successful type of mitigation.
Restoration and creation of over 806 acres of wetlands is the core of the RRWSG's Reservoir Mitigation
Plan. However, the Plan also includes preservation of another 315 acres of wetlands adjacent to the
mitigation sites. Approximately 322 acres of shoreline wetlands and shallow water habitat would
potentially develop around the reservoir itself. The project will thus result in a net gain of wetlands in
excess of 700 acres (806 + 322 - 403 = 725), and another 315 acres of existing wetlands will receive
perpetual protection. The King William Reservoir Project will thus provide a net gain of aquatic
resources within the Chesapeake Bay watershed. The project and its accompanying mitigation will work
an exchange of 403 acres of wetlands that exhibit certain elements of separation from the greater
Chesapeake Bay watershed by the downstream Cohoke Creek Millpond for more than 806 acres of
wetlands that are all directly connected to tributaries of the Bay.
The RRWSG's mitigation plan fully compensates for the loss of wetland acreage and function associated
with the King William Reservoir. When combined with the reservoir, buffer, and downstream
preservation area, the plan encompasses more than 6,100 acres of preserved land, water and wetlands,
which will be a significant contribution to the Commonwealth of Virginia's efforts to restore and preserve
the Chesapeake Bay and its tributaries.
Conclusion: Successful implementation of the RRWSG's mitigation plan will assure no net
ฐ ' . "' ' ' * -' *' ' /"'< '",-',' ; . j; "-; ^ ;ฐ;v<^"-^! ' ' s "-
loss of wetland acreage or functions and compensate for pther environmental impacts in the
reserfbir project area. ". " '|f> '*?*' '; " :i-,-.-,:- "-'?;'/-;p'"'-'-":- ' "'""' '""'' ; '*.''->/
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SECTION 2.0
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MITIGATION SITE SELECTION
The following provides a summary of milestones in the wetland mitigation site selection process, a
description of the process, and the final outcome.
2.1 HISTORY OF MITIGATION SITE SELECTION PROCESS
CONCEPTUAL MITIGATION PLAN PRESENTED IN THE DEIS (FEBRUARY 1994)
Plan Components
Creation/Restoration at 1:1 ratio for 452 acres of impacts.
Majority of mitigation involved on-site, with-in basin wetland creation:
Fringe wetland development = 50 acres
Borrow area wetland creation = 66 acres
Headwater impoundments to create wetlands = 90 acres
- Restoration of prior converted cropland = 60 acres
Off site mitigation within Pamunkey River Basin in close proximity to Cohoke Creek
watershed:
- Constructed wetlands = 186 acres
CONCEPTUAL MITIGATION PLAN PRESENTED IN THE SUPPLEMENT TO THE DEIS (DECEMBER
1995)
Mitigation Team Meetings/Site Review
February 22, 1995 - First Mitigation Team Meeting
" August 2, 1995 - Mitigation Team Meeting
Agency Directives
On-site mitigation preferred.
Mitigation sites to include large, contiguous areas with associated upland/wetland habitats.
Terrestrial mitigation required.
" Wetland functional evaluations required (i.e., EPW, HEP).
Stream mitigation required.
2:1 replacement for PFO impacts, 1.5:1 for SS, and 1:1 for EM.
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Site Identification Process
Search area for mitigation sites limited to portions of King William County (KWC) that drain
to the Pamunkey River Basin.
Reviewed (USGS) U.S. Geological Survey maps to identify ditched or drained open
areas/farm fields.
Reviewed soil surveys to identify open areas with high percentage of hydric soils.
Reviewed available aerial photography to identify open areas with wet signatures.
Plan Components
1:1 creation/restoration to offset 524 acres of impacts.
Designed to meet plan goal of "no net loss" of wetland acreage or function.
Plan comprised of approximately half restoration/ half creation.
CONCEPTUAL MITIGATION PLAN FOR THE VIRGINIA DEPARTMENT OF ENVIRONMENTAL
QUALITY (AUGUST 1996) PROVIDED IN THE FEIS (JANUARY 1997)
Mitigation Team Meetings/Site Review
November 1995 - Field Meeting with U.S. Fish and Wildlife (USFWS)
Agency Directives
Investigate additional sites in the Pamunkey and Mattaponi River Basins within King William
County and portions of New Kent and Hanover Counties.
" Mitigation plan should include anadromous fish passage restoration.
Plan should include threatened and endangered species mitigation.
Site Identification Process
Extended search area to include all of KWC and portions of New Kent, King and Queen, and
Hanover Counties that drain to the Pamunkey and Mattaponi River Basins.
Continue review of USGS maps, soil surveys, and available aerial photography within search
area to identify large tracts of land space adjacent to stream, rivers, or other wetland systems.
Contacted the Virginia Department of Forestry for identification of potential mitigation sites.
Contacted the KWC Soil Conservation Service (USDA Extension Office) for identification of
potential mitigation sites.
Contacted Ducks Unlimited for identification of potential sites.
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Coordinated with the KWC Administrators Office for the identification of potential mitigation
sites.
Contacted landowners within search area to obtain site access and identification of other
potential sites.
Identified sand and gravel mined sites for the potential to create wetter wetland systems (i.e.,
semi-permanently flooded to permanently flooded areas).
Conducted limited field investigations of sites, provided landowner agreement, to determine
mitigation potential (included evaluation of soils, source of hydrology, and landscape
position).
Coordinated with the Virginia Department of Game and Inland Fisheries to identify potential
fish passage restoration sites.
Plan Components
Provides more than 2:1 compensation to mitigate for 524 acres of impacts.
12 mitigation sites included in plan (to include one site from previous plan).
WETLAND MITIGATION PILOT STUDY (SEPTEMBER 1997)
Mitigation Team Meetings/Site Review
February 19 and 20, 1997 - Mitigation Team Field Meeting
ป April 17, 1997 - Mitigation Team Meeting
July 10, 1997 - Mitigation Team Field Meeting
" July 16, 1997 - Mitigation Team Meeting
August 28, 1997 - Mitigation Team/HEP Team Meeting
Agency Directives
Restoration preferred over creation.
Avoid small isolated areas.
Avoid sites that require substantial hydrologic manipulations and excavation.
Selection of "target" wetland types should be based on what is appropriate for the local
geographic/topographic region rather that forcing in-kind mitigation.
Provide 1:1 wetland replacement by hydrologic regime.
" Extend search area to headwaters of Pamunkey and Mattaponi River Basins.
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Preservation could be used to meet 2:1 requirement.
" Mitigate for stream impacts at a 1:1 ratio by stream order impacted.
Conduct a wetland mitigation pilot concept design study of one of the proposed mitigation
sites (Meadow Farm - Site C).
Site Identification Process
Initiated site identification process in the headwater areas of the Pamunkey and Mattaponi
River Basins to include Caroline, Spotsylvania, and Louisa Counties (to include review of
USGS maps, soil surveys, and aerial photography).
Continued site identification within the previously defined search area (lower Pamunkey and
Mattaponi River Basins).
Contacted landowners within search area to obtain site access and identification of other
potential sites.
Identified drained forested areas as potential wetland restoration sites (based on USGS maps,
soil surveys, and aerial photography).
Contacted local Virginia Department of Forestry offices for identification of potential
mitigation sites.
Continued coordination with landowners for site access, which led to identification of other
potential mitigation sites.
Conducted field investigations of potential mitigation sites.
Conducted multiple field investigations of potential mitigation sites with the Mitigation Team
to identify suitability of site for mitigation.
ป Contacted The Nature Conservancy for identification of land protection priorities related to
the KWR project.
Reviewed USGS maps to identify potential millpond dam removal for stream valley wetland
restoration and anadromous fish passage restoration.
Field investigated potential millpond dam removal sites and anadromous fish passage
restoration sites.
Coordinated with landowners regarding potential dam removal sites.
Conducted field investigations with Mitigation Team to evaluate potential dam removal sites
for stream valley wetland restoration and anadromous fish passage restoration.
Conducted field investigations of wetland preservation areas (to be used to meet 2:1
mitigation goal) with Mitigation Team.
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Plan Components
MITIGATION SITE SELECTION
Detailed analysis of site characteristics and proposed conditions (i.e., soils, hydrology,
vegetation, design).
ซ Monitoring plan to include performance criteria and contingency measures.
DRAFT WETLAND MITIGATION PLAN (OCTOBER 1997)
Agency Directives
" Complete evaluations for each mitigation site to level of detail provided in the Pilot Study.
Identify potential mitigation sites having the following favorable site qualities:
Landowner willingness.
Sites containing hydric soils.
Sand and gravel operations.
Landscape position, preferably adjacent to river or tributary, or other naturally
occurring aquatic ecosystem.
High groundwater table.
Large areas of potential restoration/creation with upland and wetland
restoration/preservation.
Sites possessing secondary water supply.
The interagency team accepts 10 identified sites for use as mitigation.
Site Identification Process
Continued mitigation site identification process described for previous plan.
Continued landowner coordination to obtain sites access and identify potential mitigation
sites.
Plan Components
Identifies 400 acres of restoration and 371 acres of creation.
Includes 10 mitigation sites (to include 9 sites from previous plan).
" 203 acres of wetland preservation.
" 711 acres of upland restoration/preservation.
Additional sites under investigation to meet the 2:1 compensation goal.
WORKING DRAFT MITIGATION PLAN (JULY 1998)
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Mitigation Team Meetings/Site Review
November 13, 1997 - Mitigation Team/HEP Team Meeting
February 23, 1998 - Mitigation Team Field Meeting
April 6, 1998 - Mitigation Team Field Meeting
June 25, 1998 - Mitigation Team Field Meeting
June 26, 1998 - Mitigation Team Meeting
Agency Directives
" Eliminate KW Sand and Gravel Site (152 acres of wetland creation).
Extend search area to greater York River drainage basin.
Evaluate four priority functions that constitute the mitigation plan's goal to achieve "no net
loss of function".
The interagency team approves of 5 identified sites for use as mitigation.
Site Identification Process
Initiated the site identification process in the greater York River Basin to include all of New
Kent, Gloucester, and Matthews Counties, and portions of James City and York Counties
(site identification process included review of USGS maps, soil surveys, and aerial
photography).
Continued site identification within the previously defined search area (all portions of the
Pamunkey and Mattaponi River basins).
Contacted landowners within search area to obtain site access and identification of other
potential sites.
ป Contacted local Soil Conservation Service Offices for identification of potential mitigation
sites.
Contacted local realtors for identification of potential mitigation sites.
Continued coordination with local County Administrators to obtain permission to search for
mitigation sites within their county.
Field investigated potential mitigation sites.
Coordinated numerous Mitigation Team field investigations of potential mitigation sites and
previously Team selected/approved mitigation sites.
Initiated mitigation site identification process in the Chickahominy River Basin.
Field investigated sites within the Chickahominy Basin.
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Coordinated Mitigation Team field investigation of potential sites within Chickahominy
River Basin.
Evaluated potential to construct reservoir headwater wetlands.
Contacted the Virginia Department of Conservation and Recreation (VDCR) for
identification of potential wetland conservation sites VDCR has noted worthy of protection.
Reviewed USGS maps to identify potential stream restoration sites.
Coordinated with landowners regarding potential stream restoration projects.
Field investigated potential stream restoration sites.
Coordinated Mitigation Team field investigations of potential stream restoration sites.
Conducted extensive field investigations of fringe wetland development at existing
reservoirs.
Coordinated Mitigation Team field investigations regarding potential fringe wetland
development around the KWR.
Coordinated with the USFWS and species expert to identify potential Small Whorled
Pogonia (a federally-listed threatened species) mitigation sites.
Coordinated with landowners regarding potential threatened species mitigation.
Field investigated potential Small Whorled Pogonia mitigation site.
Plan Components
14 sites identified in the plan provide full 2:1 wetland restoration/creation compensation (to
include 9 sites from the previous plan).
527 acres of restoration/259 acres of creation proposed.
Potential wetland preservation areas identified to meet 2:1 compensation goal.
Includes 21 miles of stream corridor restoration/preservation/enhancement.
" Provides 3 alternatives for anadromous fish passage restoration.
FINAL REVISED DRAFT MITIGATION PLAN (FEBRUARY 1999)
Mitigation Team Meetings/Site Review
August 25, 1998 - Mitigation Team Field Meeting
" August 26, 1998 - Mitigation Team Meeting
September 9, 1998 - Mitigation Team Meeting/Field Meeting
Agency Directives
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Extend mitigation site search area to include portions of the Rappahannock River Basin.
Site Identification Process
Initiated site identification process in the Rappahannock Basin (Essex and Middlesex
Counties).
Contacted landowners within search area to obtain site access and identification of other
potential sites
Field investigated potential mitigation sites.
Coordination of Mitigation Team field investigations of the mitigation sites included in the
previous mitigation plan.
Plan Components
Sites identified in the plan provide 795 acres of wetland restoration/creation.
15 sites (includes 12 of the mitigation sites contained in the previous plan).
21 miles of stream corridor restoration/preservation/enhancement.
Identifies contingency mitigation sites.
FINAL MITIGATION PLAN (MAY 1999)
Mitigation Team Meetings/Site Review
" April 7, 1999 - Mitigation Team Field Meeting
April 8, 1999 - Mitigation Team Meeting
Agency Directives
Eliminate Reservoir Borrow Area from mitigation plan (62 acres of creation).
Identify 160-200 acres of contingency mitigation acreage.
The interagency team approves of 2 identified sites for use as mitigation.
Site Identification Process
" Coordinated Mitigation Team field investigations of potential mitigation sites identified in
the Rappahannock River Basin.
Plan Components
14 mitigation sites providing 822 acres of restoration/creation (12 of the sites included in the
previous plan).
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Contingency mitigation acreage identified.
21 miles of stream corridor restoration/preservation/enhancement.
FINAL FISH AND WILDLIFE MITIGATION PLAN (MAY 1999)
Plan Components
Fisheries mitigation.
Terrestrial mitigation.
Endangered species mitigation.
RESERVOIR MITIGATION PLAN (DECEMBER 2003)
Mitigation Team Meetings/Site Review
April 10, 2003 - Mitigation Team Meeting
August 4, 5, 6, & 7 - Mitigation Team Field Meetings
August 8, 2003 - Mitigation Team Meeting
October 10, 2003 - Mitigation Team Meeting
November 3, 2003 - Mitigation Team Conference Call
November 14, 2003 - Mitigation Team Field Meeting
Agency Directives
Revise mitigation sites based on current availability.
Modify mitigation site design based on August 2003 interagency team field meeting
discussions.
ป Identify over 200 acres of contingency mitigation sites.
" Complete Phase 1 Cultural Resource Surveys of mitigation sites.
Complete mitigation site construction tiering map.
Compile requirements for compensatory mitigation to include requirements for final design
plans and specs, success criteria, and monitoring.
Revise downstream wetlands impact analysis.
The interagency team has agreed to the identification and use of the contingency mitigation
sites...
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Site Identification Process
" Initiated site identification process of contingency sites.
Contacted landowners within search area to obtain site access and identification of other
potential sites.
Field investigated potential contingency mitigation sites.
Coordinated Mitigation Team field investigations of primary mitigation sites and
contingency sites.
Plan Components
11 mitigation sites providing at least 806 acres of restoration/creation (all sites included in
the previous plan).
Over 300 acres of contingency mitigation acreage identified.
Compensation plan for over 21 miles of stream and riparian corridor to include restoration,
preservation and/or enhancement.
RESERVOIR MITIGATION PLAN (JUNE 2004)
Mitigation Team Meetings/Site Review
February 26, 2004 - Mitigation Team Meeting
June 2, 2004 - Mitigation Team Meeting
Agency Directives
Revise mitigation plan based on the March 22, 2004 U.S. Environmental Protection Agency
comment letter and the March 29, 2004 U.S. Fish and Wildlife Sendee comment letter
regarding the King William Reservoir Project December 2003 Reservoir Mitigation Plan
Plan Components
Wetland restoration/creation sites provide 2:1 compensation (806 acres), which fully offsets
impacted wetland functions. All sites were included in the previous plan. Plan identifies
approximately 300 acres of wetland restoration/creation contingency acreage.
Stream Corridor Mitigation Plan fully compensates for 21 miles of impacts. Contingency
mitigation sites, which were identified in the previous plan, provide approximately 300 acres
of wetland restoration/creation.
Wetland mitigation sites include preservation of approximately 315 acres of wetlands.
Plan includes over 2,600 acres of upland restoration and preservation.
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Preservation of downstream corridor which includes over 800 acres of wetlands and uplands.
Reservoir will provide 1,251 acres of deepwater habitat.
Approximately 322 acres of shoreline wetlands and shallow water habitat are expected to
develop around the reservoir shoreline.
Wetland education.
2.2 SITE SELECTION PROCESS
A site selection process was designed in coordination with the Corps, USEPA, USFWS, and Virginia
Department. of Environmental Quality (VDEQ) to identify optimal areas for wetland restoration and
creation. This process was followed to maximize the probability of establishing fully functional wetland
systems. Selection of potential wetland mitigation sites was pursued through a sequential process of site
screening, preliminary evaluation of site features, obtaining access to sites and establishing landowner
willingness to consider participation in a wetland mitigation project. A screening process was used to
identify sites with desirable features for wetland mitigation and eliminate those with undesirable features.
A qualitative ranking was used in the preliminary evaluation phase to classify the identified sites into
groups of high, medium and low potential for wetland mitigation. Once access to properties was obtained
from the individual counties and landowners, meetings with landowners and site reviews were conducted
to confirm each site's potential for wetland mitigation.
The federal and state agencies required that the mitigation plan offset the in-kind losses to the Cohoke
Creek riparian wetland system. Therefore, the site selection process focused on areas located
immediately adjacent to streams or river systems, and sites where stream restoration could be
incorporated into the mitigation site design to replace the loss of function provided by the riparian
corridor within the project area. Details of the site selection process are discussed below.
2.3 SITE SCREENING AND IDENTIFICATION
The initial screening step considered broad criteria such as geography; on-site vs. off-site compensation;
agency concerns; engineering considerations; and, physical, biological, and hydrological considerations.
2.3.1 GEOGRAPHIC CONSIDERATIONS
In a geographic context, the type of compensation was ranked from most desirable to least desirable as
follows: 1) On-site restoration areas, 2) On-site creation areas, 3) Off-site restoration areas, and 4) Off-
site creation areas. Potential sites were viewed in this context. Property available within the vicinity of
the reservoir pool area that was considered appropriate for wetlands creation or restoration was limited.
The site identification process then focused on potential wetland mitigation areas within the Cohoke
Creek drainage area. Once the search for appropriate sites in the Cohoke Creek drainage was exhausted,
the search area was extended to the drainage basins of the Mattaponi and Pamunkey Rivers to include
King William County and portions of New Kent and Hanover Counties. Because of landowner
unwillingness, the search area was further extended into the headwaters of the Pamunkey and Mattaponi
Rivers within Louisa and Spotsylvania Counties. Although potential wetland mitigation sites were
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identified in Caroline and King and Queen Counties, would not grant permission to the RRWSG to
explore the use of those sites.
The search area was further widened to include potential wetland mitigation areas in the greater York
River drainage basin; therefore, portions of James City, York, Gloucester, and Matthews Counties were
evaluated. When the search effort was exhausted in the York Basin, the Corps directed the RRWSG to
search for potential mitigation sites within the Rappahanock Basin. Approximately 250 potential wetland
mitigation sites were identified.
2.3.2 SITE IDENTIFICATION AND SELECTION CRITERIA
The site identification and selection process was divided into two steps. The first step included a broad
elimination of specific regions with undesirable biological and/or physical characteristics that would
impede wetland restoration or creation; the second was identification of desirable qualities and
characteristics within the remaining eligible sites. Information utilized in the site identification and
selection process consisted of topographic maps (l:24,000-scale) from the USGS, available aerial
photographs, and NRCS Soil Survey mapping. This information was used to identify cleared areas
adjacent to surface water features and cleared property on river terraces. Tax parcel maps were also used
to determine property boundaries, adjoining properties, and landowner(s) of each parcel.
As described above, the wetland mitigation site selection process focused on the identification of sites that
contained hydric soils and hydrologic features capable of restoring wetlands on a site. The results of the
HEP analysis were also incorporated into the site selection process to determine the type of mitigation
needed to offset in-kind habitat losses in the project area. In addition to the sites identified for restoration
of flooded/saturated to seasonally flooded wetland cover types, the HEP analysis indicated that wetlands
having wetter hydrologic regimes (seasonally flooded-saturated/semipermanently flooded) should also be
incorporated into the compensation plan to offset the loss of habitat for certain species evaluated within
the project area.
In the first step of the process, a list of undesirable regional conditions was established. Undesirable
conditions included:
Areas distant from streams or rivers. Creating adequate hydrology for wetland mitigation on
higher terraces is difficult and expensive.
Urbanized areas. These areas were considered infeasible due to their potential for higher land
prices, vandalism, personal injury, and undesirable pollutant impacts. *
Mature forested areas. It was considered undesirable to have significant habitat losses associated
with the placement of constructed wetland systems in these functioning ecosystems.
" Areas requiring substantial excavation activities. These areas would have excessively high
construction costs and low probability of success.
Areas containing known cultural resource sites eligible for inclusion on the National Register of
Historic Places.
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The second step included the identification of desirable site qualities and characteristics. These included:
Landowner willingness to consider participation. This was a requirement.
Wetland restoration sites containing hydric soils, such as Prior Converted (PC) croplands. These
sites were preferred because they combine lower construction costs with increased potential for
the successful replacement of lost wetland functions.
Sand and gravel operations. These were regarded as viable because of accessible groundwater
driven hydrology coupled with required mining reclamation efforts. Incorporated mitigation into
required reclamation would result in a substantial cost reduction.
Existing access to the wetland mitigation sites. Access was desired because of heavy equipment
needs during the construction phase.
Landscape position. Project sites close to a major river or tributary with neighboring existing
wetlands were preferred. These wetland mitigation sites have a greater likelihood to possess the
proper substrate, seed bank and hydrology necessary for a successful mitigation site. Sites next to
existing wetlands also maximize habitat value. Also, wetland restoration within or next to
naturally occurring aquatic ecosystems offers greater benefit than restoration of isolated areas.
Large areas of potential restoration/creation. These were preferred to enhance the functions
provided by the site.
Wetland mitigation sites possessing a secondary water supply. An alternative source of water
will increase the potential for successful mitigation.
Coordination efforts were conducted with the NRCS, Soil and Water Conservation Districts, Virginia
Cooperative Extension Agents, Virginia Department of Forestry, and City and County Planners to locate
potential wetland mitigation sites.
After conducting the initial screening and identifying sites with desirable characteristics, a preliminary
evaluation was conducted to assess each site's potential for wetland restoration or creation.
2.4 PRELIMINARY EVALUATION
Before selecting a potential wetland mitigation site, a desktop preliminary evaluation of its characteristics
favorable for wetland mitigation was completed. This evaluation was more detailed than the screening
phase discussed earlier. NRCS soil maps were used to determine the soil types present at the site. USGS
topographic survey maps were used to assess hydrologic features of the site and adjoining properties.
Aerial photographs were used to assess land use of surrounding properties. Site-specific characteristics
reviewed during the preliminary evaluation included:
Site hydrology.
Presence and extent of hydric soils and clayey subsoils.
Presence of adjacent existing wetlands.
Proximity to a river or other surface water source.
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Depth to groundwater based upon surface expressions of the water table.
" Topographic position of the site.
Surrounding land use.
" Historic land use.
Estimate of the potential wetland mitigation acreage and type.
After preliminary evaluation, sites with favorable conditions for wetland mitigation were qualitatively
ranked as having high, medium, low or no potential for wetland mitigation. Further direction from the
federal agencies resulted in the ranking of "No Potential" for sites less than 10 acres. Confirmation and
further evaluation of site features were performed during site reviews with the interagency team.
2.5 SITE ACCESS
Access and permission to review sites was obtained from county authorities and landowners. Typically,
county officials were supplied with a listing and location of the identified sites. County tax parcel maps
were used to identify landowners and then each landowner was contacted by phone or mail to request
access.
Access to Caroline and King and Queen Counties was denied by County authorities. Access was granted
to the remaining sites except for a few sites in Hanover County to which county authorities had specific
objections.
2.6 SITE RECONNAISSANCE AND REVIEW
Site reconnaissance and review consisted of a field meeting with the landowner and reconnaissance of the
site to confirm the site's physical characteristics, potential to support wetland restoration/creation, and
estimated acreage. During the field investigation, site characteristics identified during the preliminary
evaluation were verified and evaluated. Site hydrologic features, the extent of hydric soils based upon the
NRCS soil survey map and local geomorphic features were verified. Site-specific features were identified
through discussions with the landowner and the site investigation, including storm water drainage swales,
drainage tiles, drainage ditches, ponds and other physical features. Historical development and use of the
property were discussed with the landowner. When possible, photographs of the site were taken to
document site conditions at the time of the field visit. A preliminary evaluation of land use of adjoining
properties was conducted as part of the site review.
Multiple field visits were conducted with state and federal agency personnel to review sites and obtain
agency comments regarding the potential for successful wetland mitigation. Agency representatives were
provided with a site description, USGS topographic map, and soil survey map for each site reviewed
during the field meetings. During the site review, the site's physical characteristics favorable for wetland
restoration/creation, the proposed wetland restoration/creation cover types, and the estimated wetland
acreage were discussed with state and federal agency personnel.
2.7 SELECTED SITES
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After considerable evaluation and site review, 11 sites with at least 806 acres of potential wetland
restoration/creation were selected to provide the 2:1 compensation. These sites were field investigated by
the federal and state agencies and the interagency team agreed to the identification and use of the
candidate and contingency mitigation sites because these sites contain characteristics which increase the
probability of wetland mitigation success.
The wetland mitigation sites provide for the preservation, in perpetuity, of large tracts of land in areas that
are currently farmed or subjected to periodic logging, including clear cutting. In addition to providing at
least 806 acres of wetland restoration/creation, the mitigation sites include protection in perpetuity of
approximately 315 acres of wetland preservation, and 700 acres of upland restoration and preservation.
The majority of the wetland mitigation sites will include restoration and preservation of riparian buffer
areas adjacent to streams and rivers. Also, stream restoration will be incorporated into the final design of
\ f-
several of the wetland mitigation sites. The sites provide connections with existing forested wetland
systems, thereby forming extensive ecosystem complexes consisting of a variety of wetland, riverine, and
forested upland habitats.
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MALOOUVi
PIRNIE
PARTICIPANTS IN PLAN
DEVELOPMENT
Development of the mitigation plan for the King William Reservoir project has evolved over a decade,
starting with identification of mitigation goals presented in the February 1994 Draft Environmental
Impact Study (Corps, 1994). Numerous comments and agency directives followed publication of the
DEIS, prompting the RRWSG to initiate an interagency mitigation team to provide guidance for
developing mitigation goals and objectives. The first interagency mitigation team meeting was held in
August 1995. In addition to the federal and state agencies, the RRWSG solicited participation from local
Tribes, special interest groups, and wetland mitigation experts. Table 3-1 identifies the participants and
their roles in development of the mitigation plan.
The participants in plan development drove wetland mitigation site selection, which included multiple
field investigations by plan participants. Site design parameters, mitigation plan goals, and requirements
for final mitigation plan development, to be completed following permit issuance, were developed in
consultation with the mitigation plan participants. Development of the mitigation plan for the King
William Reservoir is unparalleled in its level of participation from federal and state agencies, interested
parties, and wetland mitigation experts.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 3-1
3114-017
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TABLE 3-1
KING WILLIAM RESERVOIR PROJECT
ABTiriPANTSlNPLAN DEVELOPMENT
HEP Team Member
nd Mitigation Exper
Wclland Miligalion Expert Advi
epre
rgan
n Repres
Pamunkey Indian Re
etland Mitigation Expe
KWR Wf Hand Mitigntkm Tf am Mteting
I February 22, 1995 - First Wetland Mitigation Workshop
2 August 2, 1995 - Second Wetland Mitigation Workshop
3 November 17, 1995 - Mitigation Field Work with USFWS
4 Fehruan 19,1997 - Mitigation Team Field Meeting
5 February 20,1997 - Mitigation Team Field Meeting
6 April 17, 1997-Mitigation Team Meeting
7 July 10, 1997 - Mitigation Team Field Meeting
S Julv 16,1997 - Mitigalion Team Meeting
!> August 28, 1997 - Mitigation TeanVHEP Team Meeting
10 November 13, 1997-Mitigation Team Meeting
3114-017
11 February 23, 1998 - Mitigation Team Field Meeting
12 April 6, 1998 - Mitigation Team Field Meeting
13 June 25, 1998 - Mitigation Team Field Meeting
14 June 26,1998 - Mitigation Team Meeting
15 August 25, 1998 - Mitigation Team Field Meeting
ffi August 26, 1998 - Mitigation Team Meeting
11 September 11 1998 - Mitigation Team Meeting
18 April 7 1999 - Mitigation Team Field Meeting
19 April 8 1999 - Mitigation Team Meeting
20 April 10 2003 - Miligi.lion Tumi Meeting
21 August 4-7, 2003 - Mitigation Team Field Meeting
21 August 8,2003 Mitigation Team Meclmg
23 October 9, 2003 - Mitigation Team Meeting
24 November 3, 2003 - Mitigation Team Conference Call
IS November 14, 2003 - Mitigation Team Field Meeting
26 February 26, 2004 - Mitigation Team Meeting
27 April 21 200-t Mitigation Team Meeting
28 June 2, 2004 - Mitigation Team Meeting
-------
SECTION 4.0
MALJGOyVt
PIRNIE
WETLAND MITIGATION
COMPONENT
4.1 WETLAND MITIGATION SITES
Following a rigorous selection process, the RRWSG has identified eleven wetland mitigation sites to
provide 2:1 compensation for impacts within the reservoir area. The interagency mitigation team, which
has been extensively involved in the site selection process, has agreed to the identification and use of the
candidate and contingency mitigation sites, and preservation areas, as well as the tentative acres as
described in the plan because the sites contain characteristics which increase the probability of wetland
mitigation success, given proper final designs, review agency involvement, construction oversight,
monitoring, and remediation... The sites provide a minimum of 806 acres of wetland restoration/creation,
to include 1:1 replacement by hydrologic regime, to mitigate for impacts to 403 acres of vegetated
wetlands within the Cohoke Creek basin.
In addition to the wetland restoration/creation component, the mitigation sites include protection in
perpetuity of approximately 315 acres of wetland preservation, and 703 acres of upland restoration and
preservation. The majority of the sites will include restoration and preservation of riparian buffer areas
adjacent to streams and rivers. Also, stream restoration will be incorporated into the final design of
several of the sites. The sites provide connections with existing forested wetland systems, thereby
forming extensive ecosystem complexes consisting of a variety of wetland, riverine, and forested upland
habitats. Figure 4-1 is a map of the Virginia Coastal Plain with the National Wetland Inventory (NWI)
layer "turned on" and enhanced with color (gold) to show how the eleven mitigation sites and
contingency sites connect to existing wetland systems and riparian corridors. (The NWI mapping
typically underestimates the extent of wetlands in eastern Virginia.) This figure also highlights the
adjacency of the mitigation sites to one another.
Table 4-1 provides the acreage estimates for the primary wetland mitigation sites and contingency sites.
The mitigation sites located within the Pamunkey River Basin provide more than 1:1 compensation for
impacts within the Cohoke Creek watershed. Also, over half of the mitigation sites are larger than 150
acres (total size) and construction of the three largest mitigation sites alone would provide 1:1 wetland
acreage compensation. Some mitigation sites are located in close proximity to another site. The proposed
mitigation will restore large portions of riparian corridors that were previously cleared and drained, and
the combined systems will blend together or complement each other as they mature into diverse
communities. These large, contiguous wetland-upland systems will provide substantial water quality and
wildlife habitat benefits.
For this project, wetland restoration involves the reestablishment of wetland features on prior converted
or drained agricultural fields. The majority of the 806 acres of wetland mitigation contain hydric soils,
which indicates that the site previously functioned as a wetland. Wetland creation areas are also limited
to agricultural fields. The wetland restoration/creation areas combined with the large areas of adjacent
wetland preservation and upland restoration/preservation will provide approximately 1,824 acres of
ecologically improved habitat that will be preserved in perpetuity.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-1
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TABLE 4-1
KING WILLIAM RESERVOIR PROJECT
Wetland Restoration/Creation Acreages Proposed within the Mitigation Sites and Contingency Sites
MITIGATION SITES
Wetland Restoration/
Creation
(AC)
Wetland
Preservation
(AC)
Upland
Restoration
(AC)
Phase I
King William Farm '
York River Mitigation Bank
Meadow Farm
Burlington
Subtotal =
35
161
63
24
283
38
0
17
0
55
6
0
72
14
92
Upland
Preservation
(AC)
TOTAL
(AC)
Contingency
Site Expansion 3
(AC)
23
0
19
3
45
102
161
171
41
475
10
27
37
Phase n
Lanesville
Gulasky2
Townsend
Subtotal =
37
45
117
199
11
28
0
39
36
114
75
225
0
13
1
14
84
200
193
477
4
4
25
33
Phase III , :
Island
Subtotal -
86
86
11
//
64
64
0
0
161
161
0
0
Phase IV ' ' " ' "' . .,:." - - --' '-' : '
Terrell
Rice
3avis
Subtotal =
Xigi\ ..; ..> ; TOTAL =
2:1 Replacement Goal =
195
33
10
238
.-- -f.M6<^
ป., .:,i'.; -&*jr.
0
202
8
210
/r 31S ''.'
185
54
17
256
"''' J637 ''' -
0
0
7
7
''" ' " ซ' -'- --,v
380
289
42
711
1,824
14
0
0
14
84
806
Contingency Sites
Eocene (King William County)
vlyers (Hanover County)
York River Mitigation Bank
^ew Kent Environmental Bank
3nmary Mitigation Site Expansion
Subtotal =
15
35
83
80
84s
297
109
0
49
213
371
19
46
25
52
142
0
15
79
325
419
143
96
236
670
84
1,229
]-|^Mlฃ,|iyf!3j053'l;i| v I bCI&*
1 Includes 4 1 ratio for wetland enhancement (4 acres @ 4 1 = 1 ac) combined n ith 34 acres of PC restoration
3 Includes 3 1 ratio for wetland enhancement (18 acres !a>, 3 I = 6 acres) combined \vith 39 acres of PC restoration
3 The inlcragency mitigation team agreed that hvdrofogy and soils within selected sites have potential to support larger wetland system Additional field investigations conducted for final design development will be completed to confirm proposed expansion acreage
4 Calculation docs not include remaining available ซ cllartd restoration/creation acreage at York River Mitigation Bank
s Refers to contingency acreage derived from potential expansion of the primary mitigation sites
-------
MALCOLM
PIRN1E
WETLAND MITIGATION
COMPONENT
During the August 8, 2003 mitigation meeting, the interagency team reconfirmed that final design of the
wetland mitigation sites would be completed following issuance of the Section 404 permit. The
mitigation site acreages are based on conceptual plans and may be revised based on detailed survey and
additional field investigations conducted for final design, to include detailed hydrologic monitoring and
soils testing. The RRWSG will conduct hydrologic monitoring for all the mitigation sites for at least
three consecutive years to use in the mitigation site design. The extent of grading, weir height, site
boundary, and cover type limits will be determined during final design. Minor grading will likely be
required to restore/create wetlands, but may be limited in some areas to ditch filling. The extent of
grading and weir structure elevations will be determined for final design following detailed surveys of the
site and additional field studies.
Reference sites will be used to provide detailed structural goals for mitigation design. Wetlands within or
adjacent to the mitigation sites would be used as the primary source of reference data, where available.
Another source of reference would be the wetlands within the project impact area of Cohoke Creek.
Although the physiographic position of the Cohoke Creek wetlands may not be comparable to the
mitigation sites in every instance, the physical and vegetation structure of these references will provide a
second set of feasible structural goals. The reference wetlands would also serve to refine monitoring
protocols and success criteria by which the mitigation performance will be judged. Reference sites will
be identified and sampling commenced as early in the mitigation process as possible. The initial set of
mitigation sites will serve as a short term suite of references by which each following group of sites can
be evaluated with regard to the interim stages of wetland development.
The final design plans would include modifications to avoid impacts to historic resources, if feasible. If
the Corps, in consultation with the State Historic Preservation Officer, determines that mitigation site
construction/implementation will have an adverse effect on an historic property included on or eligible for
inclusion on the National Register, a treatment plan for the avoidance, protection, recovery of
information, or destruction without data recovery of such property will be prepared.
Following Corps and VDEQ approval of a final wetland mitigation plan, to include design plans and
specifications for each mitigation site, construction will proceed in phases, starting with Phase 1 (see
Figure 4-1). The phasing of site construction was developed in coordination with the interagency
mitigation team and encourages construction of sites requiring the least amount of
groundwork/engineering followed by sites that have more involved design requirements. Therefore, any
errors in implementation or flaws in the design encountered during implementation of Phase 1, can be
corrected for the remaining sites prior to construction. Additionally, older, successful sites can serve as a
reference to help determine if "younger" sites are on the appropriate successional path.
The following text provides details on each site.
4.1.1 KING WILLIAM FARM
King William Farm, located within King William County, consists of approximately 105 acres of drained
cropland, upland areas, and existing wetlands. The site is situated on a lower terrace bordered by Boot
Swamp Creek, a tributary to the Mattaponi River, and is adjacent to forested wetlands associated with the
KING WILLIAM RESERVOIR MITIGATION PLAN Page 4-2
REGIONAL RAW WATER STUDY GROUP 3114-017
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MALCOLM
PIRN!
WETLAND MITIGATION
COMPONENT
creek and the Mattaponi River floodplain. The site is prone to flooding from the creek and receives
occasional flooding from the river during extreme rainfall events. Seepage from the steep slope on the
eastern border of the site is ditched through the site towards the existing wetlands located north of the
wetland restoration/creation area. Another ditch located on the west side of the site intercepts the
overflows of Boot Swamp Creek and drains northward through the site.
Planned mitigation on the site is shown on Figure 4-2, which also includes the NWI layer with color
(gold) to show how the site connects to existing wetland systems and riparian corridors. The majority of
the area proposed for wetland mitigation contains hydric soils. The topographic position, clayey subsoil
texture, slow permeability and poor drainage of soils at the site will support the proposed forested wetland
restoration. The high water table, observed in the northern portion of the site, creates ponded or
saturation conditions. The landowner reports that seasonal ponded or saturated conditions occur during
normal and dry years. A hydrologic analysis conducted for the King William Farm site demonstrated that
the available hydrology would support the proposed wetland restoration.
Minor earthwork would be required to restore wetlands on the site and would be limited to filling ditches
within the interior of the site, creation of shallow berms along existing contour lines, and incorporation of
microtopography. The mitigation Planned mitigation at this site is shown on Figures 4-2, which also
includes the NWI layer with color (gold) to show how the site connects to existing wetland systems and
riparian corridors. Planned mitigation at this site will provide wetland and upland restoration/preservation
conditions as outlined in the following table.
Wetland Restoration/
Creation (ac)
35*
Wetland
Preservation (ac)
38
Upland
Restoration (ac)
6
Upland
Preservation
(ac)
23
TOTAL
(ac)
105
* Includes 4:1 ratio for wetland enhancement (4 acres @ 4:1 = 1 acre) combined with 34 acres of PC restoration.
As evidenced by the adjacent wetlands immediately north of the mitigation site, restoring wetlands within
the site would create a large riverine system connected to the Mattaponi River. Wetland mitigation would
establish varying hydrologic regimes and cover types. Stream restoration credits could be generated
within the site by routing Boot Swamp Creek, which borders the site to the west, through the site.
However, success of the site is not dependent on re-routing the stream (i.e., sufficient hydrology to
support site without re-routing stream).
On-going and abandoned sand and gravel mining operations are heavily impacting the Mattaponi River
and adjacent riparian zone. Because this stretch of the river is known to contain marketable sands and
gravel, mining in this portion of the watershed is expected to continue. Mitigation on the King William
Farm property would restore and preserve in perpetuity valuable riparian systems that have been impacted
and would otherwise continue to decline.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-3
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MALOOLM
PIRNIE
WETLAND MITIGATION
COMPONENT
Currently, the mitigation site is an agricultural field, which contributes high nutrient and sediment loads
to the Mattaponi River. The functions that would be restored on the property include water quality
enhancement, flood flow alteration, sediment retention, aesthetic value, and wildlife habitat. Several of
these functions will occur immediately by taking the fields out of production.
Wetland mitigation would establish varying hydrologic regimes and cover types. Based on the hydrology
and landscape position, this area is expected to support wetlands with hydrologic characteristics ranging
from temporarily flooded/saturated to seasonally flooded. The limits of various hydrologic regimes and
associated cover types will also be determined during final design; however, forested cover types will
comprise the majority of the site with wetter systems likely to occur immediately adjacent to the water
conveyance structures.
4.1.2 YORK RIVER MITIGATION BANK
The York River Mitigation Bank is located in King William County and is comprised of approximately
505 acres of agricultural fields and existing wetlands situated within the Pamunkey River floodplain.
This operational bank was permitted by the Mitigation Bank Review Team to include the Corps, USFWS,
and VDEQ in February 2003, and serves hydrologic unit code 02080106 (hydrologic unit code of the
proposed reservoir).
Planned mitigation on the site is shown on Figure 4-3, which emphasizes the connectivity of the site with
existing wetland systems and riparian corridors. The bank includes 244 acres of available wetland
restoration/creation credits (one credit comprised of 1 acre of wetland restoration/creation),
49 acres of wetland preservation, 25 acres of riparian upland restoration, and 79 acres of
riparian upland preservation. The site will include a mix of cover types and hydrologic regimes. Stream
restoration/enhancement/preservation areas would also be a component of the bank. Currently, the
RRWSG plans to purchase 161 acres of wetland restoration/creation from the available bank credits. The
monitoring and success criteria for the bank may require modification to comply with the monitoring
requirements imposed by the federal agencies for the King William Reservoir project. The following
table identifies mitigation acreage that will be obtained from the York River Mitigation Bank for the
reservoir project.
Wetland Restoration/Creation (ac)
161
TOTAL (ac)
161
4.1.3 MEADOW FARM
Meadow Farm, located in the northern portion of King William County, consists of approximately 171
acres of prior converted cropland, pasture land, upland areas, and existing wetlands. According to the
landowner, prior to 1966, the site was a forested wet area that was cleared for farming activities. Prior to
1970, a small stream fed by groundwater seepage flowed across the southwestern portion of the site into a
swale, which separates the west and east portions of the site. Ditches were constructed in 1970 to
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-4
3114-017
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MA1COLM
PIRNIE
WETLAND MITIGATION
COMPONENT
intercept the flows from the drainage basin. Ditches were also constructed in the farm fields and
pastureland in 1970 to drain the area so farming activities could occur. Also, drainage tiles were placed in
the slope south of the site to convey groundwater to ditches and away from the site.
As shown on Figure 4-4, planned mitigation on the site will connect to existing wetlands and riparian
corridors. The soil survey coverage for Meadow Farm indicates that the entire wetland restoration area
consists of hydric soils that exhibit characteristics indicative of periodic saturation and poor drainage.
These fine-textured soils have slow to moderately slow permeability and cover the entire wetland
restoration area. The soil's slow permeability causes saturated soil conditions during the wet season.
Saturated conditions are supported, in part, by the seasonal high water table that occurs within 2.5 feet
below grade. Thus, existing soil conditions at Meadow Farm are conducive to wetland restoration. A
hydrologic analysis conducted for Meadow Farm demonstrated that the available hydrology would
support the wetland restoration proposed on the property.
Restoration of wetlands on the property will involve limited grading, to include minor grading to allow
surface water to flow across the site, to fill ditches within the site, to create hummocks, and to construct
the water conveyance channels. Mitigation at this site will provide wetland and upland
restoration/preservation conditions as outlined in the following table.
Wetland
Restoration/Creation
(ac)
63
Wetland
Preservation
(ac)
17
Upland
Restoration
(ac)
72
Upland
Preservation (ac)
19
TOTAL
(ac)
171
The final design will maximize restoration opportunities within the site without conducting extensive
excavation/grading. The height of the water conveyance structures will be determined during final design
following a detailed topographic survey and additional field investigations. The limits of various
hydrologic regimes and associated cover types will also be determined during final design; however,
forested cover types will comprise the majority of the site with wetter systems likely to occur immediately
adjacent to the water conveyance structures.
Meadow Farm is surrounded by forested upland and wetland communities. Mitigation on this site would
create an integrated ecosystem complex to include varying wetland types and valuable forested upland
habitat. The receiving stream for the Meadow Farm drainage originates upgradient in the RRWSG's
proposed Burlington mitigation site. From the Meadow Farm site, the stream is channeled to another
wetland mitigation area on the property that has been recently restored by the USFWS, in cooperation
with the Chesapeake Bay Foundation, prior to emptying to the Mattaponi River.
Currently, the mitigation is agricultural land and pastureland, which contribute high nutrient and sediment
loads to the Mattaponi River basin. The anticipated functions that would be restored on the property
include water quality enhancement, sediment retention, aesthetic value, and wildlife habitat. Several of
these functions will occur immediately on the property by taking the fields and pasture out of production.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-5
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MALCOLM
PIRN!
WETLAND MITIGATION
COMPONENT
4.1.4 BURLINGTON
Burlington Farm is located in King William County north of Aylett and is immediately west of the
Meadow Farm mitigation site. The property is currently cropland and contains an un-named tributary,
which drains through the proposed Meadow Farm mitigation area, and a recently restored wetland
mitigation site prior to emptying into the Mattaponi River. Burlington Farm is composed of
approximately 41 acres of PC cropland and upland areas.
Planned mitigation on Burlington is shown on Figure 4-4, which illustrates how the site connects to
existing wetland systems and to a riparian corridor, which drains from Burlington Farm to the Mattaponi
River. The Burlington Farm site is a relatively flat meadow area located at the toe of a moderate slope.
Soil conditions are appropriate for the proposed wetland mitigation. The entire site consists of a poorly
drained hydric soil that has moderately slow permeability. The loam to sandy clay loam subsoil and low
topographic relief results in poor drainage of the site. Water on the site is from precipitation and
groundwater seepage along the base of the slope. Drainage ditches traversing the mitigation site direct
surface water into the headwaters of the un-named intermittent tributary. The seasonal high water table
occurs within a foot of the ground surface. Because the site is flat, the water table gradient is relatively
flat, with little change in elevation across the site.
Mitigation at this site includes the wetland restoration/creation, upland restoration and preservation
combined with enhancement/preservation of a stream corridor between the Burlington site and Meadow
Farm. The site design would restore a headwater riverine system. Minimal effort will be required to
restore wetlands on the Burlington site since ample sources of hydrology are available and clayey soils
with low permeabilities exist throughout the site. Planned mitigation at this site will provide wetland and
upland restoration/preservation conditions as outlined in the following table.
Wetland
Restoration/Creation
(ac)
24
Wetland
Preservation
(ac)
0
Upland
Restoration
(ac)
14
Upland
Preservation (ac)
3
TOTAL
(ac)
41
Earthwork would be limited to ditch filling, creating minor micro-topographic features, and construction
of the water control structure. The site would be restored to a forested wetland system (temporarily
flooded to seasonally flooded).
Mitigation on Burlington Farm will include enhancement and preservation of a stream corridor system
integrated within the wetland/riparian complex, thereby, enhancing the value of the site. The functions
that would be restored on the property include water quality enhancement, sediment retention, aesthetic
value, and wildlife habitat. Several of these functions will occur immediately on the property by taking
the agricultural fields out of production.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-6
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MAUQCXM
P1RNIE
WETLAND MITIGATION
COMPONENT
4.1.5 LANES VILLE
The Lanesville site is located in King William County southwest of the proposed King William
Reservoir. The 84-acre property is currently drained cropland that adjourns Old Town Creek, a tributary
of the Pamunkey River. The Lanesville site contains a large groundwater seepage area that flows from a
topographically high area on the property. The groundwater seepage is currently intercepted by numerous
ditches, which divert the water to a roadside ditch and to Old Town Creek, which forms the western
boundary of the site.
As shown on Figure 4-5, mitigation on the site would connect with existing wetland systems and riparian
corridors associated with the Pamunkey River. The landscape position, clayey subsoil texture, slow
permeability and poor drainage of hydric soils are conducive to wetland restoration. Groundwater
seepage onto these soils creates ponded or saturated conditions for long periods. A hydrologic analysis
demonstrated that the available hydrology would support the proposed wetland restoration and creation.
Minimal effort will be required to restore wetlands on the Lanesville site since ample sources of
hydrology, predominance of clayey soils, and poor soil drainage occurs throughout the site. Planned
mitigation at this site will provide wetland and upland restoration/preservation conditions as outlined in
the following table.
Wetland
Restoration/Creation
(ac)
37
Wetland
Preservation
(ac)
11
Upland
Restoration
(ac)
36
Upland
Preservation (ac)
0
TOTAL
(ac)
84
Intermittent ditches within the property would be filled, thereby allowing for the seepage to drain across
the wetland mitigation area. Multiple culverts will be designed under the access road, which will allow
for greater distribution of the groundwater seepage across the site. The groundwater seepage area will be
protected in perpetuity and either allowed to succeed naturally or would be maintained as a grassy slope.
Drainage from the site to the road ditch will be blocked. Drainage from the roadside ditch will not be
directed onto the mitigation site. The site should receive water from the groundwater seepage area in the
northern portion of the site year-round.
Wetland mitigation for the Lanesville site will involve the creation of microtopography to establish
varying wetland cover types. Based on the hydrology available to the site and setting within the
landscape, this area is expected to support a range of wetland hydrologic regimes; however, the majority
of the site will be designed to support forested wetlands.
Mitigation will restore and create a complex of varying wetland types, valuable forested upland areas, and
riparian habitat. Although the Lanesville site is outside of the reservoir watershed, the site is located
within 2 miles of the dam and within 4,000 feet of the Cohoke Creek drainage basin. The site is bounded
by Old Town Creek and a tributary to the creek on the west and south, respectively, which drain to the
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 4-7
3114-017
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MALCOLM
PIRNH:
WETLAND MITIGATION
COMPONENT
Pamunkey River. The site design will re-establish a surface water connection between the mitigation site
and the creek, if feasible.
Currently, the mitigation site consists of agricultural fields, which contribute nutrient and sediment loads
to the Pamunkey River basin. The anticipated functions that will be restored on the property include
water quality enhancement, sediment retention, aesthetic value, and habitat. Several of these functions
will improve immediately on the property by taking the agricultural fields out of production.
4.1.6 GULASKY
The Gulasky site is a 200-acre parcel located in King William County north of Nelsons Bridge. The
mitigation site consists of agricultural fields and pastureland that has been ditched and drained. The site is
located northeast of the Pamunkey River on a terrace, and two ditches within the site divert water away
from the wetland mitigation area to the river.
Planned mitigation on the site is shown on Figure 4-3, which shows how the site connects to existing
wetland systems and riparian corridors associated with the Pamunkey River. The majority of the wetland
restoration/creation area is underlain by hydric soils. The topographic position, clayey subsoil texture,
slow permeability and poor drainage of soils at the Gulasky site are conducive to wetland restoration and
creation. A hydrologic analysis conducted for the site demonstrated that the available hydrology would
support the proposed wetland restoration and creation. The poor drainage and frequent flooding of these
soils from the ditches creates ponded or saturated conditions for long periods. These conditions were
noted during field investigations and were confirmed by the landowner. During interagency field
investigations, the agencies suggested that mitigation within the 18-acre pasture area would likely
enhance wetland functions.
Minimal effort will be required to restore wetlands on the Gulasky site since ample sources of hydrology
are available and clayey soils with slow permeabilities exist throughout the site. Mitigation at this site
will provide wetland and upland restoration, enhancement, and preservation conditions as outlined in the
following table.
Wetland
Restoration/C
reation (ac)
39
Wetland
Enhancement
at 3:1 ratio
(ac)
6
Wetland
Preservation
(ac)
28
Upland
Restoration
(ac)
114
Upland
Preservation
(ac)
13
TOTAL
(ac)
200
The final design plan will include the use of small berms to slow the movement of water across the site
and the use of shallow swales to disperse water. The intermittent ditch, which parallels the restoration
area, will be rerouted/restored through the wetland mitigation area, and will be designed as a shallow^
intermittent stream feature to include small drain swales off the stream to disperse water across the site.
Incorporation of the stream feature within the site would restore a riparian wetland system that connects
to the Pamunkey River.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
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3114-017
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MA1JOOLM
PIRN!
WETLAND MITIGATION
COMPONENT
Wetland mitigation will involve the creation of microtopography to establish varying wetland cover types.
Based on the hydrology available and setting within the landscape, this area is expected to support
wetlands with hydrologic characteristics ranging from temporarily flooded/saturated to seasonally
flooded. The majority of the site would be designed to support forested wetlands.
Mitigation will create a complex of wetlands, valuable forested upland areas, and preservation of a
forested riparian buffer on the Pamunkey River, and stream restoration. In addition to providing valuable
riparian habitat, this large mitigation area will provide a connection with forested wetland systems
upstream, downstream, and across the river, thereby, forming an extensive ecosystem complex consisting
of a variety of wetland, riverine, and forested upland habitats.
Currently, the site is agricultural land and pastureland, which contribute nutrient and sediment loads to the
Pamunkey River. The functions that will be restored on the property include water quality enhancement,
sediment retention, aesthetic value, and wildlife habitat.
4.1.7 TOWNSEND
The Townsend property, located in Hanover County southwest of the U.S. Route 360 bridge crossing of
the Pamunkey River, consists of approximately 193 acres of cropland. Several small intermittent ditches
divert water away from the mitigation area to tributaries of the Pamunkey River. Groundwater seepage
from a slope on the western portion of the property is intercepted by two ditches and diverted to a ditch
located in the center of the mitigation area. The flow within this ditch is directed westward to
Totopotomy Creek and eastward to an unnamed tributary to the Pamunkey River.
The Townsend site connects to existing wetland systems and riparian corridors associated with the
Pamunkey River, as shown on Figure 4-6. The majority of the wetland mitigation area contains hydric
soils. The very slow permeability, poor drainage and seasonal high water table of the soils creates ponded
or saturated conditions for extended periods. These soil characteristics, along with hydrologic elements,
result in site conditions that are favorable for wetland restoration. For long periods in winter and spring,
these soils are poorly drained and frequently flooded due, in part, to the seasonal high water table that
occurs at 0.5 feet below grade. The site should receive water from the groundwater seepage area in the
western portion of the site year-round. A hydrologic analysis of the Townsend site demonstrated that
adequate water is available for the restoration of wetlands.
Minimal effort will be required to restore wetlands since ample sources of hydrology are available and
clayey soils with low permeabilities exist throughout the site. Mitigation at this site will provide wetland
and upland restoration/preservation conditions as outlined in the following table.
Wetland
Restoration/Creation
(ac)
117
Wetland
Preservation
(ac)
0
Upland
Restoration
(ac)
75
Upland
Preservation (ac)
1
TOTAL
(ac)
193
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Minor grading would be required to restore wetlands on the site, and may be limited in some areas to
ditch filling. Drainage easements may be secured for hydrologic features supporting wetland restoration
on the site or for features that provide additional sources of hydrology to support site expansion (i.e.,
stream that crosses under Rt. 360 to the southwest portion of the site).
Wetland mitigation would establish varying wetland hydrologic regimes and cover types. Based on the
hydrology and landscape position, this area is expected to support wetlands with hydrologic
characteristics ranging from temporarily flooded/saturated to seasonally flooded. The limits of various
hydrologic regimes and associated cover types will also be determined during final design; however,
forested cover types will comprise the majority of the site with wetter systems likely to occur immediately
adjacent to the water conveyance structures.
Restoration of the site would provide a valuable wetland/upland complex, which will connect to a
forested riparian corridor to the north. Currently, the mitigation site is agricultural land, which
contributes nutrient and sediment loads to the Pamunkey River basin. The functions that will be restored
on the property include water quality enhancement, sediment retention, aesthetic value, and wildlife
habitat.
4.1.8 THE ISLAND
The "Island" mitigation site, located in King William County near Manquin, consists of approximately
150 acres of agricultural fields. The "Island" is surrounded by forested wetlands associated with Moncuin
Creek, tributaries of Moncuin Creek, and the Pamunkey River. Several small intermittent ditches, which
originate on the site, divert water away from the mitigation area towards the Pamunkey River. One
intermittent stream feeds a small pond and associated wetlands located in the northeastern portion of the
property. Water drains from the pond to a ditch, which drains into the floodplain of Moncuin Creek.
The site contains primarily non-hydric soils; however, clayey subsoils extend across most of the site
serving to limit infiltration and decreasing drainage. These subsoils range from 0.5 to 3 feet thick.
Hydric soils occur along three separate drainage channels.
As shown on Figure 4-7, mitigation on the "Island" would connect with wetland and riparian systems that
surround the site associated with Moncuin Creek, its tributaries, and the Pamunkey River. Intercepted
storm flow from Moncuin Creek will be diverted to the "Island" to provide an adequate source of water
for wetland restoration/creation. Direct precipitation onto the site and occasional flooding by the
Pamunkey River will provide additional sources of water. A monitoring program, implemented for at
least three consecutive years prior to final design, will determine the base flow and storm flow elevations
of Moncuin Creek and its side channels so that an appropriate method for bringing storm flow onto the
site can be selected and designed. Elevations of the "Island" range between 5 and 10 feet msl with
wetlands at elevations of less than about 5 feet msl in Moncuin Creek.
Ample sources of hydrology coupled with clayey subsoils with low permeabilities will foster the
creation/restoration of wetlands on the site. Mitigation will provide wetland and upland
restoration/preservation conditions as outlined in the following table.
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Wetland
Restoration/Creation
(ac)
86
Wetland
Preservation
(ac)
11
Upland
Restoration
(ac)
64
Upland
Preservation (ac)
0
TOTAL
(ac)
161
Grading will be required to create/restore wetlands, but may be limited in some areas to ditch filling and
creation of microtopographic features. Wetland mitigation will involve the creation of microtopography
to establish varying wetland cover types. Based on the hydrology available and setting within the
landscape, this area is expected to support wetlands with hydrologic characteristics ranging from
temporarily flooded/saturated to seasonally flooded. The majority of the site will be designed to support
forested wetlands. The site is surrounded by forested wetlands, which will provide an abundant seed
source for the mitigation area.
Mitigation on the site will create a unique wetland-upland ecosystem complex integrated with the high
structural complexity and ecological value of the adjacent wetlands. Preservation of this system will
provide an extensive tract of varying wetland types within the floodplain of the river.
Sand and gravel mining operations are on-going immediately upstream, impacting the riparian zone of the
Pamunkey River. Because riparian zones are known to contain marketable sands and gravel, mining in.
the watershed is expected to continue. Mitigation on the "Island" will restore and preserve in perpetuity
valuable riparian systems that have been impacted and will continue to decline.
Currently, the mitigation site is cropland, which contributes nutrient and sediment loads to the Pamunkey
River basin. The functions that would be restored on the property include water quality enhancement,
sediment retention, aesthetic value, and wildlife habitat. Several of these functions will occur
immediately by taking the agricultural fields out of production.
4.1.9 TERRELL
The Terrell site consists of approximately 380 acres in northern Essex County and drains to the
Rappahanock River basin. This is the only RRWSG proposed mitigation site located out of the York
River drainage basin. However, this is an ideal site for wetland restoration for the reservoir project.
Restoration here would offset approximately half the wetland acreage impacted within the reservoir
impact area, and a mix of cover types and hydrologic regimes would be restored adjacent to existing
wetlands, streams and existing riparian corridors.
The site is a relatively flat expanse of farmland with very slight knolls and depressions. Planned
mitigation on the site is shown on Figure 4-8, which illustrates how the site connects to existing wetland
systems and riparian corridors.
The soils consist predominantly of poorly drained hydric soils characterized by a seasonal high
groundwater table and a slow to moderately slow permeability, which enhances the poor drainage. The
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property has a multitude of swales, ditches, and drain tiles designed to carry surface and ground water to
natural drainage ways to promote farming activities. The property lies at the base of a large hill and
receives amble supplies of surface water runoff from the hill and groundwater seepage from the base of
the hill. A hydrologic analysis of the Terrell site has demonstrated that adequate water is available for the
restoration of wetlands on the property.
Minimal effort will be required to restore wetlands since ample sources of hydrology are available and
clayey soils with low permeabilities exist throughout the site. The entire site consists of hydric soils and
only minor grading would be required to plug ditches and restore hydrology. Mitigation will provide
wetland and upland restoration/preservation conditions as outlined in the following table.
Wetland
Restoration/Creation
(ac)
195
Wetland
Preservation
(ac)
0
Upland
Restoration
(ac)
185
Upland
Preservation
(ac)
0
TOTAL
(ac)
380
Wetland restoration would require minor grading to allow surface water to flow across the site, to create
hummocks, to fill ditches, and to construct the water conveyance channels. A ditch on the western and
northern boundary of the site currently intercepts groundwater seepage and runoff from Highway 17. The
ditch, would be plugged, filled, or routed through the site to provide additional hydrology to the
mitigation area.
Wetland mitigation would establish varying wetland hydrologic regimes and cover types. Based on the
hydrology and landscape position, this area is expected to predominantly support temporarily
flooded/saturated, forested wetlands. The limits of various hydrologic regimes and associated cover types
will also be determined during final design; however, forested cover types will comprise the majority of
the site with wetter systems likely to occur immediately adjacent to the water conveyance structures.
Currently, the mitigation site consists of agricultural fields, which contribute nutrient and sediment loads
to the Rappahannock River basin. The anticipated functions that would be restored on the property
include water quality enhancement, sediment retention, aesthetic value, and wildlife habitat. Several of
these functions will occur immediately on the property by taking the fields and pasture out of production.
Restoration of this large site, to include wetland and upland restoration, will combine with adjacent
wetlands and riparian corridors to provide an extensive ecosystem complex.
4.1.10 RICE
The 289-acre Rice site is located in King William County near Manquin, immediately west of the
"Island" mitigation site. The property is currently used for agriculture and drains to Moncuin Creek, a
tributary of the Pamunkey River. The site is bordered by the Pamunkey River and associated wetlands,
and wetlands along Moncuin Creek.
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Several small intermittent ditches transect the mitigation area and drain to Moncuin Creek. The
mitigation area is within the floodplain of Moncuin Creek and the Pamunkey River. According to the
landowner, the property is frequently flooded.
Planned mitigation on the Rice site is shown on Figure 4-7, which illustrates how the sites connects to
existing wetland systems and riparian corridors, and combines with the "Island" site forming an extensive
ecosystem complex. Hydric soils occurring on the Rice site are poorly to very poorly drained with a
seasonal high water table at the surface to 2.5 feet below grade. The fine textured subsoil of hydric and
non-hydric soils at the Rice Property, along with the frequently flooded or saturated conditions of the site,
are conducive for wetland restoration and creation. Areas of ponding observed on several field visits
confirmed the poor drainage of these soils.
A hydrologic analysis conducted for the Rice Property has demonstrated that the available hydrology
would support the proposed wetland mitigation. The intermittent ditches would be filled or graded to
provide sheet flow across the site. The site will also receive water from the overflow of Moncuin Creek
and occasional flooding of the Pamunkey River.
The moderately slow permeability of these soils will promote ponding or saturated near-surface
conditions. Mitigation will provide wetland and upland restoration/preservation conditions as outlined in
the following table.
Wetland
Restoration/Creation
(ac)
33
Wetland
Preservation
(ac)
202
Upland
Restoration
(ac)
54
Upland
Preservation
(ac)
0
TOTAL
(ac)
289
The final design plan will minimize grading to establish temporarily flooded to seasonally flooded
forested wetland systems. Wetland mitigation would involve the creation of microtopography for the
establishment of varying wetland types. Overbank flooding of Moncuin Creek and occasional flooding
from the Pamunkey River would provide hydrology to support the wetland system. During the August 6,
2003 field investigation, the interagency mitigation team suggested minimizing grading to restore a
wetland system interspersed with upland inclusions. Full wetland credit would be given for the
wetland/upland mosaic, as agreed to by the agency team (to include VDEQ) during the August 8, 2003
interagency meeting.
An abandoned roadbed/berm, which currently precludes floodwaters from Moncuin Creek from spilling
onto the restoration area, will be removed to allow for overbank flooding. Monitoring of Moncuin Creek
(stream gage) will be required for final design of the site. Monitoring will occur for at least 3 consecutive
years prior to site construction. Based on data collected for the final design phase, areas requiring
significant amounts of excavation to capture overbank flooding will be excluded from the final site plan.
The final design plan may include additional modifications to avoid impacts to historic resources.
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The Rice Property is immediately adjacent to the "Island" mitigation site, therefore, mitigation on these
sites would create an extensive wetland-upland ecosystem complex unique in function and value due to
the high structural complexity and ecological value of the adjacent wetlands and river corridor.
Preservation of this system would provide an extensive tract of varying wetland types within the
floodplain of the river and would provide a valuable riparian-forested buffer along the Pamunkey River, i
f *
Sand and gravel mining operations are on going on property immediately upstream from the Rice site,
impacting the riparian zone of the Pamunkey River. Because riparian zones along the river are known to
contain marketable sands and gravel, mining in the watershed is expected to continue. Mitigation on the
Rice site will restore and preserve in perpetuity valuable riparian systems that have been impacted and
will continue to decline.
Currently, the mitigation site is agricultural land, which contributes nutrient and sediment loads to the
Pamunkey River. The functions that will be restored on the property include water quality enhancement,
flood flow alteration, sediment retention, aesthetic value, and wildlife habitat.
4.1.11 DAVIS
Davis Farm is located in New Kent County immediately south of Plum Point. The site is currently used
for agriculture and is bisected by Baker Creek, a tributary of the York River. Baker Creek floods portions
of the proposed mitigation area during storm events. Within the mitigation site, a culvert associated with
a farm road crossing of Baker Creek currently impedes drainage from the site. Small depressional areas
are located in the farm field, and standing water was noted in the depressional areas during late summer.
Planned mitigation on the site is shown on Figure 4-9, which also shows how the site connects to existing
wetland systems and riparian corridors. The majority of the site consists of non-hydric soils that have
fine-textured subsoils conducive to wetland mitigation. Stormflow from the intermittent reach of Baker
Creek that transects the site would be used to supplement runoff to the site and direct precipitation. The
hydrologic analysis conducted for the Davis Farm site has demonstrated that the available hydrology
would support the proposed wetland creation.
Of the RRWSG proposed mitigation sites, this site provides the smallest acreage of wetland
restoration/creation; however, its total mitigation project area is 42 acres, and the site is hydrologically
connected to other wetlands and riparian systems. Mitigation will provide wetland and upland
restoration/preservation conditions as outlined in the following table.
Wetland
Restoration/Creation
(ac)
10
Wetland
Preservation
(ac)
8
Upland
Restoration
(ac)
17
Upland
Preservation
(ac)
7
TOTAL
(ac)
42
The site involves restoration and preservation of a riverine system, restoration of riparian wetlands, and
wetland creation. Based on the existing depressional topography, the mitigation site will mimic
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restoration of "Delmarva Bay" systems. These systems include wetland/upland mosaics. Full wetland
credit would be given for the mosaic areas, as agreed to by the agency team (to include VDEQ) during the
August 8, 2003 interagency mitigation meeting. Grading would be required in the western portion of the
site in non-hydric soil areas to achieve wetland hydrology.
Mitigation would include headwater wetland creation and preservation, upland restoration and
preservation, and connection with a stream corridor that drains through a forested wetland system to the
York River. Creation and preservation of this ecosystem complex would integrate the wetland/riparian
complex associated with Baker Creek, thereby, enhancing the value of the site. The limits of various
hydrologic regimes and associated cover types will be determined during final design.
Currently, the mitigation site is an agricultural field, which contributes nutrient and sediment loads to the
York River. The functions that will be restored on the property include water quality enhancement,
sediment retention, aesthetic value, and wildlife habitat.
4.2 CONTINGENCY MITIGATION SITES
If it were determined during the final design phase of the wetland mitigation plan that site conditions, or
construction costs would result in a reduction of acreage for some of the mitigation sites, contingency
sites would be used to complete the 2:1 compensation. The RRWSG has identified approximately 297
acres of contingency wetland creation/restoration to include additional areas within the York River
Mitigation Bank (see Figure 4-3), another operational mitigation bank (New Kent Environmental Bank)
located within the same hydrologic unit code as the reservoir (see Figure 4-10), and two sites located
within the Pamunkey River drainage basin (see Figures 4-11 and 4-12). The owners of the New Kent
Environmental Bank have demonstrated a willingness to participate with the RRWSG and have
incorporated design modifications, to include stream restoration, based on interagency mitigation team
comments. Hydric soils underlie the majority of the mitigation area and the current design minimizes
grading within areas of hydric soils to ensure that the proposed mitigation fits the landscape position,
resulting in restoration of a forested wetland system. The design parameters are comparable to the
requirements for design and implementation of the primary mitigation sites. The Bank owners have also
agreed to modify proposed land use within the Bank and within their adjacent property in response to
agency concerns.
Based on observed hydrology and soil characteristics, many of the primary mitigation sites may be
expanded to provide additional wetland restoration/creation acreage. If inclusion of a contingency site is
required to meet the 2:1 goal, additional field investigations will be conducted to determine the extent and
design of wetlands within the mitigation area.
Of the 297 contingency acres, only 14 acres are located outside of the York River Basin, which includes
expansion of one of the primary mitigation sites (Terrell). The interagency team has agreed to the
identification and use of the contingency mitigation sites. Figure 4-1 illustrates the close proximity of the
contingency sites to the primary mitigation sites. Recognizing that the primary sites and contingency
sites were chosen for their excellent characteristics and their high probability for wetlands establishment
success, any combination of these sites (providing 2:1 compensation or 806 acres) would provide full
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wetland functional replacement. If needed, the RRWSG would continue to look for suitable contingency
wetland mitigation sites following permit issuance.
4.3 REQUIREMENTS FOR WETLAND COMPENSATORY MITIGATION
The following requirements were derived from the Norfolk District and VDEQ "Draft Recommendations
for Compensatory Wetland Mitigation" (July 2003), and encompass: requirements for final design plans
and specifications; success criteria; potential permit conditions related to construction; monitoring;
bonding; and restrictive language for protection in perpetuity. They are intended to guide development
and implementation of site-specific compensatory wetland mitigation plans following permit issuance.
The requirements may be modified on a site-by-site basis according to information provided during final
mitigation site design (to account for varying success criteria), and are worded to allow flexibility while
maintaining oversight by the Corps and VDEQ. Prior to mitigation site construction, the site-specific
compensatory mitigation plans must be approved by the Corps and VDEQ. Successful implementation
of the mitigation requirements and conditions should insure success of the mitigation effort.
4.3.1 DEFINITIONS
Compensatory mitigation: An action taken that provides some form of substitute aquatic resource for
the impacted aquatic resource.
Wetland Creation: The manipulation of the physical, chemical, or biological characteristics of a site to
develop a wetland on an upland or deepwater site, where a wetland did not previously exist. Successful
wetland creation or establishment may result in a gain in wetland acreage.
Wetland Restoration: The manipulation of the physical, chemical, and/or biological characteristics of a
site with the goal of returning natural/historic functions to a former wetland. Successful wetland
restoration may result in a gain in wetland acreage and/or improvement in wetland functions.
Wetland Enhancement: The manipulation of the physical, chemical, and/or biological characteristics of
an existing wetland (disturbed or degraded) site to heighten, intensify, rehabilitate, or improve specific
function(s), which may result in impairment of other functions, or to change the growth stage or
composition of the vegetation present.
Wetland Preservation: The removal of a threat to, or preventing the decline of wetland conditions in
perpetuity by an action in or near a wetland.
4.3.2 REQUIREMENTS FOR FINAL WETLAND MITIGATION SITE DESIGNS AND
SPECIFICATIONS
1. Goals and objectives
Goals and objectives would be expressed as acres of wetlands, vegetation type, and wetland classes
(Cowardin) proposed for the site. Similarly, the goals and objectives of buffer areas would be specified,
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to include acreage and cover types expected within the buffer areas. (Examples might include:
restoration of palustrine forested wetlands with an oak component on former agricultural lands for
wildlife habitat; creation of seasonally flooded forested wetlands in a riverine floodplain for floodwater
storage, water quality, and habitat.)
2. Location map
The site would be depicted on a 7.5' USGS topographic map with the quadrangle name clearly labeled,
and project boundaries would be clearly marked. The site drainage basin and 8-digit Hydrologic Unit
Code (HUC) Catalog Unit for the mitigation project site would be identified on the map.
3. Water Budgets
Water budgets to include results of pre-final design groundwater monitoring and/or overbank flooding
data would be completed. A hydrograph showing monthly changes in water level would also be
provided. Soil infiltration rates would be measured at various locations within the restoration/creation
areas.
Gauge station data would be collected for systems driven by overbank flooding. Stream gauges would be
installed and monitored for three consecutive years during the fall to spring period. The water budget for
overbank flow designs would be calculated using a minimum 10-year continuous simulation to account
for variability in inputs and outputs under a variety of conditions. Available gauge station data would be
used to calculate the water budget.
Shallow monitoring wells and nested piezometers would be used for three consecutive years during the
fall to spring period to better identify seasonal fluctuations in the hydroperiod, to evaluate the potential
groundwater component of a planned wetland, and to determine whether the site's hydrology is likely to
be supported primarily by a groundwater or surface water component.
4. Grading Plan
The grading plan would depict both existing and proposed topography, using at least one-foot contour
intervals. The plan would identify the location and extent of any existing wetlands on the mitigation site.
Drawings would include plan view and typical sections. The plan would also include a summary of
hydrologic calculations and/or hydrographs and indicate whether the hydrologic regime of the planned
wetland is driven by groundwater or surface water and provide supporting data. Design drawings (plan
and profile views) would also be provided for water control structures and erosion control measures.
Mitigation sites would not be graded completely flat or level, but would incorporate pit-and-mound
microtopography to mimic natural wetland areas; thereby, increasing surface water storage and providing
for greater habitat diversity for flora and fauna. Plan sheets would include photo references, to include
photos of constructed pits and mounds and woody debris piles (i.e., photo of recently constructed feature
and photo with vegetation established), and photos of reference wetlands. Upland areas would grade
gently into mitigation sites utilizing gentle side slopes (> 6:1).
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Drawings would identify the location and extent of any inholdings, easements, or right-of-ways on or
adjacent to the mitigation site, including ingress-egress, drainage, utility, and transmission lines.
(Specific design features would guide implementation but some flexibility in grading maybe needed in
order to adapt to actual field conditions.)
Passive water control structures utilizing natural materials, especially earth and rock would be used, when
feasible, in favor of structures requiring regular and active management and maintenance or structures
made of aluminum, plastic, steel, or concrete which may pose maintenance concerns in 20 or more years.
5. Plant Species List and Planting Plan
Methods for wetland vegetation establishment include: natural regeneration; direct seeding; bare root
seedlings; cuttings; container stock; ball and burlap plantings; and tubelings. Transplanting wetland
species from adjacent wetland systems would also be considered. The plant list and planting scheme for
each mitigation site would be based on site characteristics and adjacent wetland communities, and would
likely consist of one or more of the following methods.
For establishment of a mast-component in a planned forested wetland, consideration would be given to
extending planting of the mitigation site over a number of years, instead of front-loading the plantings in
the first few years. This would allow the site to stabilize through natural succession, and provide more
suitable conditions for establishment of many of the more shade-tolerant mast-producing species.
Natural recruitment is an important and often overlooked component of vegetation establishment on
mitigation sites. In regenerating forests, tree seedlings and coppice sprouts typically number in the
thousands to tens of thousands per acre. It may not be practical to plant seedlings at those densities, but
those densities may be necessary to ensure adequate stand stocking and stand structure. Thus, recruitment
from surrounding areas, especially by light-seeded and pioneer species (red maple, sweet gum, loblolly
pine, black willow, sycamore, etc.) would be considered in any revegetation scheme.
When working with slow growing species like oaks or hickories, forest establishment may be accelerated
through the use of faster growing nurse species [trainers] like loblolly pine, black willow, alder, wax
myrtle, sycamore, or cottonwood. These nurse trees shade competing vegetation like allellopathic turf
grasses [Bermuda grass and tall fescue], add organic matter to the soil, often fix atmospheric nitrogen,
and increase vertical structural complexity. In some cases, nurse crops can create a scrub-shrub stage
community within 3 years and a closed canopy within 10 years. This strategy promotes rapid colonization
by birds and may enhance beneficial public perception of the mitigation sites.
If planting were recommended on a mitigation site, planting would not be conducted until three
consecutive years of monthly hydrologic data taken during the fall and spring period (taken every two
weeks except for the first ten weeks of the growing season) is obtained and evaluated to ensure that the
planting scheme and species are compatible with the observed hydrology.
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a. Reliance upon natural regeneration would be appropriate when:
The site is adjacent to an existing wetland system;
ป The site is exposed to flood waters bearing seeds (i.e. overbank flooding);
The original soils and hydrology have not been significantly altered; or
A seedbank dominated by non-invasive species is known to be present.
b. Direct seeding may be used to establish both heavy mast (oaks and hickories) and light seeded species
(maple, sweet gum, beech, ash, and elm). Seeds from local sources, especially materials onsite or on
adjacent properties would be considered.
Oaks and hickories have been established on extensive areas of seasonally saturated soils in the
southern U.S. through direct seeding. If the site has been cultivated for a long time, it would be disked
or chisel plowed at least twice prior to planting in order to break up any plow pan or compacted soil
and to reduce herbaceous and woody competition. If tilling were required, the site would be tilled to a
depth of 8-15 inches. Any tillage would be done when the soil is drier than field capacity (freely
drained but still moist). Tillage on moist to wet soils will either lead to a subsequent traffic pan beneath
the tillage depth or "slurping around" of the surface if its at or approaching saturation. Acorns would be
planted at a depth of 1-6 inches anytime from late fall until late April. Acorns would be planted by
hand or using a modified 1 or 2 row bean planter. A conservative germination rate of 35% can be
expected.
Consideration would also be given to planting an annual cover crop (i.e. buckwheat, annual rye, wheat,
or millet) concurrently with seeding operations to stabilize soils and delay establishment of weedy
competition.
Seeding specifications would include:
The quantities of pure live seed (including numbers of acorns per acre);
" (It may not be possible to determine the percentage of pure live seed from locally collected [field
collected materials], except acorns.)
The seeding window (dates for seeding);
Use of filler (such as sand) to dilute small or light seeds for uniform coverage;
Seeding technique including equipment and implements.
Any seeds would conform to the Virginia Seed Law (Sections 3.1-262 Code of Virginia) and Virginia
Seed Regulations (2 VAC 5-290-10 et seq).
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c. Bare root seedlings:
Seedlings (to include oaks, ashes, hickories, and sweet gum) would be successfully planted or
established, provided seed rain from nearby sites allows for establishment of lighter-seeded pioneer
species (sweet gum, red maple, box elder, etc.).
d. Cuttings may be used to establish fast growing early successional species like willows, cottonwood,
and alder.
Fast growing and short-lived native tree species (e.g. some willows and cottonwoods) may be planted
as cover crops or nurse trees with slower growing more shade tolerant tree species interplanted. The
nurse trees will provide shade to promote establishment of some shade tolerant species (e.g. oaks and
hickories), contribute organic matter to recently disturbed soils, help loosen or turnover the soils
within the rooting zone, and provide scrub-shrub habitat for many neotropical migratory bird species.
e. Nursery grown container stock can be planted later in the season than bare root seedlings. Container
stock, and balled and burlap plantings have higher survival rates in heavy clay soils than bare root
seedlings. Container stock is also more tolerant of long duration saturation or inundation than bare
root seedlings. Wet-acclimated plant materials will not be planted since such materials are expensive
to obtain, are grown under stress, have less well-developed roots, and may be at a competitive
disadvantage. Specifications for containerized stock would match industry standards (1, 2, 6, and 10
gallon containers). Plant materials that are acclimated to similar climate conditions as the location of
the mitigation site would be preferred for use (within the same or an adjacent NRCS Land Resource
Region or USD A growth zone).
f. Transplanting pole sized specimens (and their associated root ball) from nearby wetlands sites will be
investigated, if feasible. This would provide a more mature initial planting along with the attendant
mound with the existing invertebrate, microfloral, and microfaunal "inoculant."
6. Soil Preparation and Amendments
When site preparation entails excavation of the A and/or B-horizon, the topsoil would be stockpiled for
use in the created wetland; thereby, reducing the need for additional organic amendments. If that is not
possible, the site may need to be over excavated 6-12 inches (depending on site hydrology/groundwater
inputs) and a comparable amount of high quality topsoil, organic soil, muck, or composted organic
material added. Where the site has been graded down to the original subsoil (B or C horizon), sufficient
organic matter (topsoil, compost, leaf mold, etc.) could be added to bring soil organic matter content to at
least 5% (this could be as much as 6-10 inches of material).
Unless the site objective is to create a system supported solely by precipitation (a "perched" or epi-
saturated system), the subsoil would be ripped or chisel-plowed to a bulk-density of less than 85 Ibs/cubic
foot (1.35 g/cc) prior to adding organic matter or topsoil to the site. This will facilitate groundwater
interchange and the rooting of many woody species. Clayey soils would be disked to a depth of 6-8 inches
in place of ripping or chisel plowing. Deliberate compaction of soils and subsoils will not be conducted.
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A soil management strategy would be developed for each mitigation site. Wide track low ground pressure
equipment would be used on "soft" or moist soils. If heavy equipment were operated repeatedly on
wetland restoration/creation soils, measures would be taken to reduce compaction and soil bulk density.
The actual soil amendment prescription would involve a standard agricultural analysis of the existing site
soil, and an equivalent analysis of the properties of the proposed organic amendment source. If organic
matter supplements are required, the organics would be spread over the site and the site surface would be
tilled with a chisel-plow or heavy disk to loosen the soil to a bulk density of less than 85 Ibs/cubic foot;
thereby, reducing compaction from final grading and mixing the organics in the surface horizon to
promote establishment of vegetation on the site. Clayey soils would be disked to a depth of 6-8 inches in
place of ripping or chisel plowing. Wetland creation sites would also be screened for sulfidic materials.
7. Reference Wetlands
The plan would identify potential reference wetland areas adjacent to or near the planned wetland
restoration/creation site that would be used as models for structural components of the mitigation design.
Hydrologic regime, micro topographic variation, and coarse woody debris composition of reference
wetlands would be evaluated. Sufficient sampling will be conducted to establish the range of height, size
and spacing of physical structures (pits and mounds, woody debris) to be replicated on the surface of the
restoration sites. To guide monitoring and help evaluate success, the reference wetlands would be used as
models for the proposed hydrologic regime and/or plant community. The selection and sampling of
reference sites would vary from site to site.
8. Adjacent Land Use/Plans
The final design plan would consider existing and future landscape features or public issues that may
control or influence design, to include effects on roads, right-of-ways, and utilities, as well as on drainage,
including the potential for flooding both upstream and downstream of the site. The plan would also
evaluate potential effects of adjoining land uses, including roads, right-of-ways, utilities, and drainage
easements on the mitigation site and its success and functions. The final design plan would certify that
the site is in compliance with FAA Advisory Circular 150/5200-33.
9. Abatement/Control Plan for Undesirable Plant and Animal Species
The final design plan would include control of competing vegetation such as volunteer herbaceous and
woody species. Only herbicides that are specifically labeled for aquatic applications would be used,
unless other herbicides that are free of damaging surfactants are suitable.
The final plans would include requirements for assessing the threat, effect and opportunity for control of
undesirable plant species. Plans would specify the threshold percentage of invasive species that would
trigger remedial action. Measures for controlling herbivory would also be discussed in the final plan and
would include the use of tree tubes, fencing, nurse crops, trapping, hunting, chemical deterrents, attracting
predators, removing cover for herbivores, etc.
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10. Construction Timetable
A construction timetable would be provided as an addendum to the final plans and specification to include
construction methods and a list of equipment that would likely be used during construction.
11. Real Estate Instruments for Perpetual Protection
A written description of the legal means used to protect the compensatory mitigation site in perpetuity
would be provided (i.e. deed restriction, restrictive covenants, easement, natural area dedication, etc.).
12. Contingency Plan
Although the site designs would be flexible to allow for minor modifications to adjust for potentially
wetter/drier than predicted conditions, a contingency plan would also be developed for dealing with
unanticipated site conditions or changes. Mid-course corrections or refinements to the final design plans
and specs may be made based on the success of prior implemented RRWSG mitigation sites.
13. Monitoring and Long-term Management
Methods would be identified for measuring plant survival, presence or absence of invasive species, and
verification of the planned wetland hydro logic regime. The party or parties responsible for accomplishing,
maintaining, and monitoring the mitigation would be identified, as well, as the type, frequency, and
duration of monitoring.
4.3.3 SUCCESS CRITERIA FOR WETLAND MITIGATION SITES
The RRWSG will provide a site-specific monitoring plan for each of the creation/restoration areas to
evaluate the success criteria (these criteria may vary from one monitoring period to the next). The same
success criteria will be applied to each site. However, the number, orientation, and location of sampling
points will vary for each site (the variations will be specified in the final design plan for each site).
If the performance criteria are not met at any time during the monitoring period, a proposal detailing
corrective actions and/or maintenance actions (if any), and an implementation schedule for those actions
would be provided. Following review and approval/modification of those measures by the Corps and
VDEQ, the necessary corrective measures would be implemented. Upon completion of the corrective
measures, a written summary of the work would be provided to the Corps and VDEQ. Additional
remedial actions may be required if the corrective measures do not result in satisfaction of performance
criteria during the next subsequent growing season. Should corrective actions not be completed, the
Corps and VDEQ would use the performance bond to fund the corrective actions.
1. Hydrology:
a. At a minimum, the site shall meet the hydrology criteria for a wetland under the 1987 Corps of
Engineers Wetland Delineation Manual and associated guidance. Soils shall be inundated or
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saturated to within 12 inches of the surface for a duration equal to a minimum of 12.5% of the
growing season, measured in consecutive days. Saturation or inundation within 12 inches of the
surface for a duration of between 5% and 12.5% of the growing season, measured in consecutive
days may be acceptable provided strong corroborative indicators of wetland hydrology (blackened
leaves, algal mats, common occurrence of oxidized rhizospheres, etc.) are present at the sampling
station under "typical precipitation conditions." For the design, the normal growing season will
be based on soil temperature or killing frost-free days in the local soil survey.
b. Visual observation of standing water within 12" of the surface (as opposed to well data) may,
under certain circumstances, be considered a positive indicator of wetland hydrology (i.e.,
saturation to the surface) as stated on page 38 of the 1987 Corps of Engineers Wetland
Delineation Manual. When using water table within 12" of the surface as an indicator of
hydrology, care would be used to consider conditions and the soil types (i.e., to ensure that the
capillary ability of the soil texture is considered in regard to the water table depth).
c. The following describes the hydrologic regimes and associated wetland cover types to be
constructed:
i. Palustrine E cover type - seasonally flooded/saturated cover types require a hydrologic range
of 75% to 100% inundation or saturation within the growing season.
ii. Palustrine C cover type - seasonally flooded cover type requires a hydrologic range of 25% to
75% regular inundation or saturation within the growing season.
iii. Palustrine A/B Cover types - temporarily flooded/saturated requiring a hydrologic range of
12% to 25% regular inundation or saturation within the growing season.
d. Demonstrate that the timing of water on the site will parallel that of targeted reference areas. This
will be accomplished using well/staff gauge measurements at a sufficient number of sampling
points. Characterization of shallow groundwater in reference sites should be sufficient to serve as
a template for restored wetland hydrology.
e. Appropriate actions will be taken where necessary to protect sources of hydrology for
maintaining wetlands within the mitigation sites (i.e., ownership or contractual mechanisms).
2. Vegetation:
Depending on the features of each site, the requirements for the establishment of viable vegetative
communities may vary considerably. Selected planting, seeding, and/or natural colonization may be
implemented. The goal will be to maximize the survivability of the wetland community with minimal
expenditure of biological and engineering resources. Planting of the mitigation sites may be extended
over a number of years, instead of front-loading the plantings in the first couple of years. This would
allow the site to stabilize through natural succession, and provide more suitable conditions for
establishment of many of the more shade-tolerant mast-producing species. Therefore, success criteria
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would probably vary from one monitoring period to the next. Active management will be limited to
control of nuisance species. Reference wetlands may provide goals for vegetation establishment. At later
time monitoring intervals (e.g. time year 5 for the first group of phased sites), the conditions at older sites
can serve as interim reference areas for younger sites.
a. Woody Plants:
" Limited planting of woody plants (primarily heavy mast species) will be. monitored by
sampling the survivability rate at appropriate time intervals.
Colonizing wetland plants will be inventoried and quantified via survey or at fixed intervals,
plots or transects.
More than 50% of all woody plants expressed either by plant stems or canopy coverage shall
be facultative (FAC) or wetter (FACW or OBL).
b. Herbaceous Plants:
More than 50% of all dominant herbaceous plant species shall be facultative (FAC) or wetter
(FACW or OBL). Areal coverage shall be a minimum of 50% in emergent wetland areas
after one growing season.
c. Unless given written approval by the Corps and/or VDEQ, the compensation site will not be
planted before the completion of the first three consecutive years during the fall to spring period
following grading. Hydrologic conditions across the site for that period would be evaluated to
select appropriate vegetation, which is compatible with the projected water elevations and
duration. Following evaluation of the hydrologic information, the Corps and/or VDEQ may
require waiting through an additional spring growing season in order to ascertain whether
hydrology is sufficient to meet the site's goals.
d. The Corps, VDEQ, or the permittee may, at any time during the monitoring period, require
removal, treatment or management of undesirable plant or animal species, including physical
removal, use of herbicides, live trapping, confining wires or nets, etc. Herbicide applications must
be conducted in accordance with all State/Federal application laws and regulations.
3. Soils:
a. For coarse textured soils (e.g. coarser than sandy loam): Ground water monitoring wells must
demonstrate a free water table from 0-6 inches below the soil surface for 15 consecutive days.
Indicators of soil reduction (including redox depletions, hydrogen sulfide, Mn-Fe concretions,
redox concentrations, etc.) within 6.0 inches or less of the soil surface would also denote hydric
conditions.
b. For fine textured soils: Ground water monitoring wells must demonstrate a free water table from
0-12 inches below the soils surface for 15 consecutive days. Indicators of soil reduction within
12.0 inches or less of the soil surface would also denote hydric conditions.
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4.3.4 Monitoring Report Criteria
The conditions below may be incorporated into the site-specific monitoring plans, modified or dropped,
as necessary, to address site-specific conditions. Monitoring requirements may change, at the direction of
the Corps/VDEQ, if a mitigation site has failed to achieve site-specific success criteria. Under some
circumstances, such as sustained attainment of performance criteria, the Corps and VDEQ may agree to
drop the requirement for monitoring of one or more wetland criteria over all or part of a mitigation site.
1. Monitoring of the mitigation sites will be conducted over a 20-year period. Reports shall be required
for nine (9) of the monitoring years following the end of the first growing season (e.g. 1, 2, 3, 5, 7, 10,
13, 16, 20). Monitoring years may differ by site to account for varying planting schemes. Planting of
some of the mitigation sites may extend over a number of years to allow the site to stabilize through
natural succession. Monitoring-years will be specified in the site-specific monitoring plans completed
for each of the mitigation sites, which require approval by the Corps and VDEQ.
2. At a minimum, mitigation site data would be collected during the killing frost-free period as defined
in the local soil survey. Vegetation data may be collected anytime between the spring and fall. At a
minimum, hydrologic data should be collected early in the growing season (i.e. late February to June).
Reports would be prepared between June 1 and November 30. The report will indicate dates at which
all information in the report was collected.
(It may be necessary to adjust the dates for collection of vegetation data in order to address site-
specific conditions such as identification/detection of plantings.)
3. Reports will include:
a. Wetland boundaries plotted on the site plan based on results of hydrology and vegetation data,
and calculation of total wetland acreage based on that boundary.
b. Photographs showing a view of the wetland area taken from fixed-point stations from a height of
approximately five to six feet from each monitoring well. Photos should be taken in each of the
four cardinal directions (north, east, south, and west). Permanent markers shall be established to
ensure that the same locations on the site are monitored in each monitoring period.
c. Hydrologic information, including both raw data and a hydrograph established using these data
for the mitigation and reference area(s).
i. Groundwater data (Well design and installation shall be consistent with current Corps
guidance (i.e., Sprecher, 2000), and must be accepted by the Corps and VDEQ prior to
installation):
The number of groundwater wells would be based on the acreage of each type of planned
wetland on a given site (palustrine emergent, palustrine forest, etc.). Wells in a given
wetland cover type would be placed at roughly the same elevation to provide more detailed
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data for different wetland types or landscape positions. The minimum numbers of monitoring
wells, based upon design acreage, are recommended to be:
<10.0 acres: 1 monitoring well /1.0 acre (rounded to the next whole acre)
10.0 acres to 50.0 acres: 1 monitoring well / 1.0 acre (rounded to the next whole acre) for
the first 10.0 acres, then 1 monitoring well / 2.0 acres for the remaining acreage.
>50.0 acres: 1 monitoring well / 1.0 acre (rounded to the next whole acre) for the first
10.0 acres, then 1 monitoring well / 5.0 acres for the remaining acreage.
For sites larger than 300 acres, the maximum number of monitoring wells should be left
to the discretion of the Corps and VDEQ, after considering input from the permittee.
Every site using groundwater wells would have at least 3 wells to evaluate static groundwater
levels on site. Additional wells may be necessary when the mitigation plan identifies a
number of wetland zones or areas with different intended hydrologic regimes. Monitoring
wells would be calibrated against test pits. Nested piezometers may be needed if the planned
wetland relies upon determination of groundwater movement, vertical gradients and/or and
epiaquic or "perched" hydrologic regime.
The wells will be monitored weekly for ten consecutive weeks beginning at the initiation
of the region's growing season. For sites designed to be seasonally or temporarily
saturated, at least one full year of monthly data (taken every two weeks except for the
first ten weeks of the growing season) would be required. Well data would be correlated
to precipitation data over the same period. This can help identify and address overly
compacted soils, perched water tables, etc.
ii. Surface water depths observed during well monitoring will be reported.
d. Vegetation data for the mitigation and reference area(s).
i. Woody plants
Survival of planted materials in each field, cell, or zone in the mitigation site would be
quantified (percentage). The health and vigor of surviving plantings would be described for
each species. The prognosis for survival and/or cause(s) of mortality would be identified, if
possible.
Inventory and density counts of colonizing woody species would be conducted. Sample
plots would be selected randomly at a ratio of 1 plot/acre for woody plant monitoring. The
plot size would be 20 feet by 20 feet square or a 30-foot radius. Transects or other accepted
methodologies (such as line intercept methods) may be used in lieu of plots, but would be
identified prior to conducting sampling.
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ii. For herbaceous plants
Measurements of percent cover are recommended. Sample plots would be selected randomly
at an average of 1 plot/acre for herbaceous plant monitoring. As an alternative that may
entail fewer sampling points, a species-area curve could be generated from the species list
collected from sample plot data. Plot size should be 40 inches by 40 inches square or an 18-
inch radius. Transects or other accepted methodologies (such as line intercept methods) can
also be used in lieu of plots.
iii. Identify zone(s) where each sample plot is located.
e. The project site soils would be described in situ before construction, with the soil profile
carefully described for redoximorphic features and USDA-NRCS hydric soil indicators. This
will allow identification of relict redoximorphic features. A comparison of pre and post
construction soil features will allow one to determine whether the redoximorphic features are
relicts or associated with active processes. Soil data should also be collected for the mitigation
and reference area(s) following the third year of monitoring. At a minimum, within 30 feet of
each well site, the soil would be evaluated per the Corps 1987 Wetland Manual and may include
supplementary indicators using the NTCHS Field Indicators of Hydric Soils per HQUSACE, 21
March 1997 Guidance (Environmental Laboratory, 1987).
g. Invasion by any undesirable species such as Phragmites, purple loosestrife, cattails, reed canary
grass, fescue or animal species such as Canada geese, rodents, and deer would be identified. The
extent of invasion of undesirable plants would be quantified; either by stem counts or percent
cover, whichever is appropriate. Damage done by animal species would be described and/or
quantified. Percent cover of invasive species would be specified for each field or cell in the
mitigation site.
h. Wildlife observations, recording actual use of wildlife would be completed. For casual
observations, the date of observation, number of individuals, presence of juveniles, and use of the
site would be recorded for each animal observation. A list of wildlife species using the site and
the nature of that use (breeding, foraging, etc.) may be sufficient.
i. Remedial actions conducted since the last monitoring report would be reported (modification,
relocation of water control structures, control of invasives, grading, soil amendments, deep
ripping or chisel plowing of soils, additional planting, etc.).
4.3.5 Post Monitoring Assessment
A post-monitoring assessment of the condition of the mitigation site would be performed following
completion of mitigation site monitoring. The assessment would include:
1. Summary of the original or modified mitigation goals and a discussion of the level of goal
attainment.
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2. A calculation of the area of wetlands on site using the Corps 1987 Wetland Manual; a scale
drawing of wetland boundaries; and supporting data sheets.
3. A comparison of the area and extent of delineated wetlands in the mitigation area and extent of
wetlands required in the mitigation plan (i.e. post construction survey).
4. Photographs of the mitigation site taken from the same locations as the monitoring photographs.
5. A description of any significant problems and any recommended solutions during construction and
monitoring of the mitigation site.
6. Identification of agency policies and procedures that encumbered implementation of the mitigation
plan. Note would be made of any policies or procedures that contributed to less success or
effectiveness than anticipated.
7. Recommendation of measures to improve efficiency, reduce cost, or improve effectiveness of
future projects.
4.3.6 Performance Bond
Since construction of the mitigation sites will occur in tiers, financial assurance may transfer from
one tier to another, or could be staggered from one site to another based on an agreed upon level
of completion. This will be determined by the reviewing agencies.
4.4 CULTURAL RESOURCES WITHIN THE MITIGATION SITES
Pursuant to 36 CFR Part 800, Protection of Historic Properties, regulations implementing Section 106 of
the National Historic Preservation Act of 1966, as amended, 16 U.S.C. 470f, and 33 CFR Part 325,
Appendix C, Processing of Department of the Army Permits: Procedures for Protection of Historic
Places, the U.S. Army Corps of Engineers (Corps) is required to take into account the effects of federally
permitted undertakings on properties included in or eligible for inclusion in the National Register of
Historic Places. As part of this process, the Corps is required to consult with the State Historic
Preservation Officer (SHPO).
With respect to the King William Reservoir project, the City of Newport News (City), the Corps, the
State Historic Preservation Office (SHPO), the Advisory Council on Historic Preservation (ACHP), and
local Indian tribes, will sign a Memorandum of Agreement (MOA) to serve as the basis for satisfying the
requirements of Section 106. The MOA will provide a framework for the identification, evaluation, and
mitigation of adverse effects to all significant historic properties that will be impacted by the proposed
reservoir project, to include the mitigation sites. The initial identification and survey of the proposed
mitigation sites has been completed (except on mitigation sites where the RRWSG has been denied access
at the present) and the Archaeological Resource Management Report is being finalized for completion in
May 2004. Table 4-2 provides the status and level of activity that has been completed. Language is
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Table 4-2
King William Reservoir Wetland Mitigation Sites
Status of Section 106 Activities
'-Site /'*
Meadow
Burlington
York River
Mitigation Bank
The Island
Rice
Lanesville
King William
Farm
Gulasky
Eocene
(Contingency)
Wetland
Restoration/
Creation Area
63
24
n/a
86
33
37
38
45
n/a
Access
X
0
0
0
a
X
0
a
0
.." : ' . :!*-~', ,., ' '
v. ."*'*' Activity' , ' :\\,
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
"; -''' '.l**'^ '' '..ป'< * :^> ',,'<
'' >ซ:,, , ",'" -, *," ''" ; Status .. -/' ;.
Recently updated
Access denied; deferred to Programmatic Agreement
Deferred to Programmatic Agreement
March 2004
Recently updated
Completed December 2003
Done
March 2004
n/a
n/a
n/a
Approved report for YRMB is on file with VDHR
Recently updated
Completed December 2003
Done
March 2004
Recently updated
To be completed by mid-January 2004
Completed December 2003
March 2004
Recently updated
Access denied; deferred to Programmatic Agreement
Done
March 2004
Recently updated
Walkover to be completed in January 2004
Done
March 2004
Recently updated
Walkover completed in 1999 with excellent visibility
Done
March 2004
Completed November 2003
Contingency site; deferred to Programmatic Agreement
Deferred to Programmatic Agreement
Preliminary assessment completed November 2003
ฃ
8J
ฃ
a
Davis
New Kent
Environmental
Bank
(Contingency)
10
n/a
a
0
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Archival research
Field survey
Landscape/ Architectural
Assessment
Report
Recently updated
Walkover of one field completed in 1999; shovel test to be completed in
January 2004
Done
January 2004
n/a
n/a
n/a
Approved report for NKEB is on file with VDHR
0)
0)
3114-017
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Table 4-2
King William Reservoir Wetland Mitigation Sites
Status of Section 106 Activities
Townsend
Myers
(Contingency)
117
n/a
0,X
m
Archival research
Field survey
Landscape assessment
Architectural survey
Report
Archival research
Field survey
Landscape assessment
Architectural survey
Report
Recently updated
92 acre walkover in 1999 with excellelt visibility Other 98 acres denied
access; deferred to Programmatic Agreement
Done
Done
January 2004
Completed November 2003
Contingency site; deferred to Programmatic Agreement
Deferred to Programmatic Agreement
Deferred to Programmatic Agreement
Preliminary assessment completed November 2003
o
o
c
re
I
x
o
V)
V)
LLJ
Terrell
195
m
Archival research
Field survey
Landscape assessment
Architectural survey
Report
Recently updated
Walkover completed December 2003
Done
Done
January 2004
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being included in the Memorandum of Agreement (MOA) to cover the work to be done at sites not yet
accessible.
The Corps, SHPO, ACHP and the KRWSG have agreed to treat all archaeological sites, to include the
wetland mitigation sites, as "districts" of eligible sites. Treatment plans will be developed with tribal
participation and review to conduct further investigative work and, where deemed appropriate and desired
by the tribes, data recovery. Properties may be avoided either through mitigation site design changes or
the use of specified construction techniques, such as site burial in accordance with an approved plan. If
data recovery is the only viable treatment option, then a data recovery plan shall be developed. The plan
shall be consistent with the Secretary of the Interior's Standards and Guidelines for Archaeological
Documentation (48 FR 44734-37, September 29, 1983) and take into account the Council's publication,
Treatment of Archaeological Properties (1980).
The RRWSG is are aware of two sites, the Island site and the Rice site, that may have significance and
these will be approached with the same care and the realization that, at that point, some changes in the
wetland design may be required to avoid significant sites. The MOA will afford compliance under
NHPA, as evidenced by the agreement between the Corps, SHPO and ACHP on the approach for
Traditional Cultural Properties mitigation.
4.5 REGULATORY GUIDANCE LETTER 02-2
The Corps recently developed supplemental regulatory guidance on compensatory mitigation projects for
aquatic resource impacts under their guidance program pursuant to Section 404 of the Clean Water Act
and Section 10 of the Rivers and Harbors Act of 1899. The regulatory guidance letter (RGL 02-2)
published on December 24, 2002 clarifies and supports the National Policy for "no net loss" of wetlands.
It does not modify existing mitigation policies, or regulatory guidance such as the 1990 MOA, but
provides guidance by which permittees must provide appropriate and practicable mitigation for authorized
impacts to aquatic resources.
Some of the major points of guidance and clarification include:
" Encourages the use of a mix of habitats such as open water, wetlands, and adjacent uplands in
mitigation projects to provide a greater variety of functions.
Seeks to assure that mitigation plans are compatible with existing laws through coordination with
tribes, local governments, and other Federal agencies.
Promotes the evaluation of the practicability of the compensatory mitigation to replace functional
losses recognizing that the "no net loss" policy may not be achieved for each and every project.
Encourages the use of functional assessments rather than acreage to evaluate compensatory
mitigation.
Allows the Districts to give compensatory mitigation credit for preservation when used in
conjunction with other establishment or restoration activities.
Recognizes that credit can be given for upland areas and for riparian areas.
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Recognizes that buffers may be needed to ensure the mitigation performs as expected. It also
recognizes that the buffers themselves provide a variety of aquatic habitat functions.
Recognizes that mitigation banks or in-lieu fee arrangements may be appropriate for
compensatory mitigation.
Provides guidance on the contents of compensatory mitigation plans.
The RRWSG has recognized these points of clarification in RGL 02-2 and has incorporated these
guidelines by developing a watershed approach with a variety of supporting elements. These elements
include wetland restoration, wetland establishment, wetland preservation, upland buffer preservation,
upland restoration, stream buffer restoration and preservation, and large-scale natural system riparian
preservation. Additionally, a functional assessment involving "priority functions" as agreed upon by the
interagency mitigation team for the project was used to evaluate the goal of no net loss of wetland
functions.
4.6 REFERENCES
Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report
Y-87-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.
Sprecher, S. W. 2000. "Installing Monitoring Wells/Piezometers in Wetlands,"
ERDC TN-WRAP-00-02, U.S. Army Research and Development Center, Vicksburg, MS.
U.S. Army Corps of Engineers, Norfolk District (Corps) and Virginia Department of Environmental
Quality (VDEQ). 2003. Draft "Corps and DEQ Recommendations for Wetland Compensatory
Mitigation: Including Site Design, Permit Conditions, Performance and Monitoring Criteria"
(July, 2003).
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SECTION 5.0
MRNI
COHOKE CREEK DOWNSTREAM
PROTECTION
5.1 INTRODUCTION
This section provides an evaluation of downstream protection in Cohoke Creek below the proposed King
William Reservoir (Dam Site IV). This evaluation includes specific programs to protect down-stream
conditions to which the Regional Raw Water Study Group (RRWSG) is committed as well as a
comparison to other similar projects. The remainder of this section is organized as follows:
1 "| Avoidance and Minimization of Downstream Wetland Impacts.
| e Minimum Reservoir Releases.
: Contributing Drainage Area Below Dam Site IV.
Natural Flow Regime.
Sediment Loading and Wetland Maintenance.
Water Temperature Maintenance.
Comparison to Releases from Other Reservoirs.
ป Downstream Corridor Preservation.
Conclusion.
5.2 AVOIDANCE AND MINIMIZATION OF DOWNSTREAM
WETLAND IMPACTS
The 1990 Memorandum of Agreement (MOA) between the U.S. Environmental Protection Agency
(USEPA) and the Department of the Army addresses the policies and procedures to be used in the
determination of the type and level of mitigation necessary to demonstrate compliance with the Clean
Water Act Section 404(b)(l) Guidelines (Guidelines). Specific mitigation requirements are defined by
the mitigation sequencing rules.
The first sequencing step, avoidance, requires an evaluation of practicable alternatives by permit
applicants to confirm that the selected project will have the least adverse impact on the environment. The
second sequencing step requires permit applicants to make appropriate and practicable efforts to minimize
unavoidable impacts. Finally, permit applicants must provide compensation for the remaining wetlands
impacted by discharges.
The RRWSG exercised the principles of avoidance and minimization by locating the reservoir within a
stream segment where wetlands are already separated from direct connection to the Pamunkey River by
the existing Cohoke Millpond. The dam and road (Route 632) crossing the dam at Cohoke Millpond is
clearly visible in the following aerial photograph taken in 1994. The Cohoke Millpond dam impounds
this creek system and is located approximately 3.5 miles downstream of the currently proposed Dam Site
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IV. The 300-year-old Cohoke Millpond dam cuts off the tidal connection from the downstream wetlands
and Pamunkey River which, in this color infrared photograph, appears in a lighter blue color.
Cohoke Millpond Dam and Lower Cohoke Creek Connecting to the Pamunkey River
Figure omitted
The location of the King William Reservoir project area is shown below. The RRWSG's currently pro-
posed project (Dam Site IV) is a clear example of efforts to minimize wetland impacts. At the direction
of the Norfolk District Corps of Engineers (Corps), and recommendations by the U.S. Fish and Wildlife
Service (USFWS) and USEPA, the RRWSG relocated the proposed dam site 1.7 miles upstream from the
original location (Dam Site I) to Dam Site IV, to reduce wetland impacts by 216 acres. This wetlands
savings resulted in a 9 billion gallon (42 percent) reduction in storage capacity from 21.2 to 12.2 billion
gallons. King William Reservoir storage capacity has already been reduced as much as possible such
that, in combination with already implemented conservation programs and brackish groundwater
desalination, it is still able to meet the basic project purpose. The specific locations of the originally
proposed Dam Site I, next proposed Dam Site II, and currently proposed Dam Site IV are all shown on
the next page 5-4 on U.S. Geologic Survey (USGS) topographic mapping.
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Figure omitted
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33% Wetland Impact Reduction via 42% Volume Reduction
Figure omitted
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5.3 MINIMUM RESERVOIR RELEASES
As stipulated in the Virginia Department of Environmental Quality (VDEQ) Virginia Water Protection
(VWP) Permit, minimum King William Reservoir releases must equal the median monthly flows of
Cohoke Creek at Dam Site IV. Prior to fall 1998, there was no streamflow gauge on Cohoke Creek and,
therefore, it was necessary to estimate median monthly flows based on flows on other streams where
gauges have existed for several years. The DEQ staff advised the RRWSG that an appropriate method for
estimating median monthly flows at the dam site would be to identify a surrogate streamflow gauge on a
nearby stream with characteristics similar to Cohoke Creek, and to apply run-off coefficients derived
from that gauge to Cohoke Creek at the dam site. The RRWSG identified the nearby streamflow gauge
on Totopotomoy Creek near Studley in Hanover County, Virginia (USGS Gauge 01673550) as an
appropriate surrogate for Cohoke Creek. Like Cohoke Creek, Totopotomoy Creek is a Pamunkey River
tributary; but unlike Cohoke Creek, 25 years of flow data are available for Totopotomoy Creek.
Using streamflow data for Water Years 1978 to 1996, median monthly flow rates were computed for
Totopotomoy Creek (26.2 square mile drainage area) and adjusted to the smaller drainage area above
Dam Site IV (8.92 square miles). These estimated median monthly flows for Cohoke Creek average 4.0
mgd and range from 1.3 mgd in September to 6.8 mgd in March as shown in the following figure. The
estimated average Cohoke Creek flow at Dam Site IV is 5.5 mgd based on Totopotomoy Creek
streamflow records for Water Years 1978 through 2002.
o 4
King William Reservoir Minimum Releases
(Totopotomoy Creek Based Median Monthly Flows)
Jan
Feb
Mar
Aug
Sep
Oct
Nov
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To comply with the VWP Permit requirement, it is estimated that an average release of 4.0 mgd (varying
monthly between 1.3 and 6.8 mgd) must be made. This is only a 27% flow reduction, when compared to
average estimated flow of 5.5 mgd at Dam Site IV.
In August 1998, the USGS began monitoring water stage and, beginning in October 1998, streamflow
measurements became available for Cohoke Creek at Route 626. Average monthly flows measured in
Cohoke Creek from October 1998 to September 2002 are compared below to those estimated for Cohoke
Creek based on the Totopotomoy Creek gauge. Over the 4-year period, Totopotornoy Creek monthly
flows exceeded measured Cohoke Creek flows by an average of 8 percent and reasonably tracked flow
patterns observed in Cohoke Creek. Absent a longer flow record for Cohoke Creek, Totopotomoy Creek
still appears to be a reasonable surrogate gage for use in establishing required King William Reservoir
minimum releases (Figure 5-5).
Average Monthly Cohoke Creek Measured Flows and Flow Estimates
(October 1998 - September 2002)
24
22
20
18
16
I Cohoke Creek
i Totopotomoy Creek Based
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Oct-98 Jan-99 Apr-99 Jul-99 Oct-99 Jan-00 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 Oct-01 Jan-02 Apr-02 Jul-02 Oct-02
State-mandated median monthly flow releases from King William Reservoir would substantially exceed
natural Cohoke Creek flow levels that would otherwise occur during drought conditions. For example, it
is estimated that Cohoke Creek flows at Dam Site IV would have averaged 1.1 mgd over the 6-month
period June 1981 through November 1981. In comparison, the State-permitted release schedule would
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average 2.2 mgd over these 6 months, or 100 percent more than would have naturally occurred in a
drought without the reservoir.
Using actual October 1998 to September 2002 flow measurements in Cohoke Creek, comparison was
made between measured flows and estimated release requirements using the Totopotomoy Creek based
median monthly flow levels (see figure below). VDEQ-mandated median monthly flow minimum
releases would substantially exceed natural Cohoke Creek flow levels that would otherwise occur during
drought conditions such as occurred in 2002. On average, over the 4-year period, King William
Reservoir minimum releases would have exceeded measured Cohoke Creek flows by about 12 percent.
Our analysis substantiates the DEQ Director's May 2, 2001 statement to the Norfolk District Corps that:
"The SWCB (State Water Control Board) took a conservative stance in reserving such a large amount of
water to Cohoke Creek."
Average Monthly Cohoke Creek Measured Flows and Flow Estimates
(October 1998 - September 2002)
10
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Cohoke Creek Measurements
BKWR Minimum Release (
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Totopotomoy
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Oct-98 Jan-99 Apr-99 Jul-99 Oct-99 Jan-00 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 Oct-01 Jan-02 Apr-02 Jul-02 Oct-02
The Virginia Department of Environmental Quality (VDEQ) Virginia Water Protection (VWP) Permit
stipulates the King William Reservoir releases at Dam Site IV. The release regime can be reconsidered
by VDEQ when the VWP permit comes up for renewal in 2007. The applicant would be amenable to
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implementing a variation of the natural flow regime, similar to the Service's proposal, with a modification
that would secure the project's safe yield while avoiding significant impacts to the downstream system.
The flow rates would be measured daily at the existing streamflow gauges on Totopotomy Creek and
Cohoke Creek, and the desired Cohoke Creek flow would be calculated as a function of the Totopotomy
Creek and Cohoke Creek streamflow, prorated based on the comparative ratio of the two watersheds. The
applicant would estimate the flow originating as seepage through the dam and complement that flow with
an appropriate release of water from the reservoir. However, during high flow events, if the reservoir is
not full and overflowing, the minimum release would be limited to the median monthly flow of the
gauges, corrected to the magnitude one would expect for the Cohoke Creek watershed. If the reservoir is
full, spills would occur during storm events. The RRWSG would not endorse a release schedule that
would further reduce the project's safe yield beyond the reduction already incurred through the VWP
permit conditions.
5.4 CONTRIBUTING DRAINAGE AREA BELOW DAM SITE IV
As shown below, approximately 12,675 feet (2.4 miles) of stream are located along the main channel of
Cohoke Creek between Dam Site IV and the upper end of Cohoke Millpond. Based on 1994 topographic
maps prepared by Air Survey Corporation, water surface elevations decline from 27.6 feet msl near Dam
Site IV to 3.5 feet msl at Cohoke Millpond.
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Figure omitted
Understanding post-reservoir hydrology below King William Reservoir requires consideration of the
natural basin runoff that would still occur from the additional 7.4 square miles of watershed that drains to
Cohoke Millpond below Dam Site IV. More specifically, an additional 4.5 square miles of the Cohoke
Creek watershed drains to Cohoke Creek between Dam Site IV and the upper end of Cohoke Millpond,
and 2.9 square miles more drain directly to the Millpond below its upper end. The additional contributing
drainage areas below Dam Site IV associated with various points along Cohoke Creek are graphically
presented below.
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Cohoke Creek Contributing Drainage Area
(Between Dam Site IV And Upper End Of Cohoke Millpond)
2,000 4,000 6,000 8,000 10,000
Channel Distance Below Dam Site IV (feet)
12,000
14,000
Runoff from the additional watershed below Dam Site IV would substantially increase downstream flows
above the level provided by King William Reservoir releases and seepage losses. For example, using
Totopotomoy Creek surrogate gage flow records for October 1977 to September 2002, an estimated mean
flow of 10.1 mgd now reaches Cohoke Millpond from an estimated 16.3 square mile drainage area. With
King William Reservoir in place and operating as permitted by DEQ, an estimated average flow of 4.0
mgd would be released from the reservoir. An additional average flow of 4.6 mgd would be expected
from the remaining 7.4 square miles of Cohoke Millpond drainage area below the reservoir. The total
post-project average flow of 8.6 mgd (4.0 + 4.6 mgd) to Cohoke Millpond would be only 15 percent less
than the pre-project estimate of 10.1 mgd. This represents only a one-seventh (1/7) flow reduction to
Cohoke Millpond.
5.5 NATURAL FLOW REGIME
Most of the time, King William Reservoir will be full and releasing more than median monthly flows
when intense storm events occur and reservoir spills -occur in excess of median monthly flows. This
would reduce the average flow reduction at Dam Site IV to even less than 27 percent, and even less than a
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15 percent flow reduction at the upper end of Cohoke Millpond. Detailed modeling analysis based on
simulation of VWP Permit operating conditions was conducted as part of Malcolm Pirnie's October 2000
"Evaluation of Safe Yield Benefits from King William Reservoir Project". Of note, the VWP Permit
limits transfer from King William Reservoir to Diascund Reservoir to a 26.5 mgd maximum 36-month
running average. This condition effectively requires that use of the existing Newport News Waterworks
system be maximized, including Chickahominy River withdrawals, before relying on Mattaponi River
flows and King William Reservoir storage. Based on Malcolm Pimie's analysis, even under 2040 to
2050 conditions, when RRWSG demands are projected to require full use of King William Reservoir safe
yield, the reservoir would still be full in 59 percent of the simulated months (see figure below). Thus,
opportunities for high natural flow pulses below Dam Site IV would be preserved the majority of time. In
earlier years, when customer water demands are less, the reservoir would be full even higher percentages
of time, as demonstrated in analysis presented in Malcolm Pirnie's October 1997 "King William
Reservoir - Reservoir Fringe Study."
110
100
90
80
70
60
50
40
30
20
10
KWR Volume Under Projected 2040 to 2050 Demand Conditions
(October 1929 - September 1987 Simulation)
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10 20 30 40 50 60 70 80
Percentage of Months Storage Level is Exceeded
90
100
Another way of looking at how often the reservoir would be full is to examine how predicted reservoir
storage levels fluctuate during the historical model simulation period. The following figure shows a 20-
year subset of the model simulation period that includes the mid-1950s drought period, which is the
drought of record for this scenario. Even several decades into the future, when the full King William
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Reservoir safe yield capacity will be needed to supply projected customer demand, the reservoir would
still be full and overflowing in response to storm events over the reservoir watershed. In fact, over this
20-year portion of the simulation period, King William Reservoir was full 64 percent of the time. In
several instances, there were multiple consecutive years that the reservoir would be full nearly all of the
time, covering all months of the year.
KWR Volume Under Projected 2040 to 2050 Demand Conditions
(20 Years of Simulation Including Mid-1950s Drought of Record)
Jan-40 Jarv-41 Jan-42 Jan-43 Jan-44 Jan-45 Jan-46 Jar>-47 Jav48 JaM9 Jan-50 Jan-51 Jan-52 Jan-53 Jan-54 Jan-55 Jan-56 Jan-57 Jan-58 Jan-59 Jan-60
Blue shaded periods denote when reservoir is full and would spill in excess of median
monthly flow releases hi response to storm events hi the Cohoke Creek watershed.
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5.6 SEDIMENT LOADING AND WETLAND MAINTENANCE
As previously discussed, supplemental runoff would be derived from the 7.4 square miles of watershed
located between the Cohoke Millpond dam and the currently proposed Dam Site IV. This large down-
stream watershed area should also continue to provide substantial sediment loads to help support natural
maintenance of wetlands within Cohoke Creek, thereby providing a balance between erosional and
depositional rates in the Creek.
The Cohoke Creek watershed has been impacted by dams, silviculture, agriculture, and numerous beaver
dams, and is transected by numerous logging and hunting trails and several public roads (including some
that are abandoned and no longer mapped). Wetlands within Cohoke Creek currently have no protection
from surrounding upland impacts. Currently, silviculture provides significant impacts to the Cohoke
Creek system, including sediment loading. As reported in the Norfolk District Corp's EIS, in 1994
approximately 65 percent of the watershed was being used for silviculture. Evidence of significant recent
timbering activities can be seen in the 1994 aerial photography of the watershed shown on the following
page. Year 2000 aerial photos indicate that an additional 764 acres of forest have been subsequently
cleared.
The creek system is impounded by the Cohoke Millpond dam located approximately 3.5 miles down-
stream of the currently proposed Dam Site IV. The centuries old dam at the millpond location cuts off the
tidal connection from the downstream wetlands and Pamunkey River. Nutrient and sediment export to
the downstream tidal estuary only occurs when storm flows top the dam.
The dimensions and dynamics of the existing Cohoke Creek channel between Dam Site IV and the upper
end of Cohoke Millpond are influenced primarily by beaver activity. There is no identifiable channel in
this reach. The wetland cover types below Dam Site IV reflect the intensive beaver activity in the area
with a continuous series of beaver dams along this reach. Some examples of beaver dams in this reach
are shown in an aerial photograph shown on a subsequent page. About 95 percent of the wetlands along
this reach of the main Cohoke Creek channel are emergent, scrub-shrub, and mixed wetland cover types --
indicative of a palustrine wetland system which is highly affected by beaver activity.
Beaver pond hydrology, in conjunction with the aforementioned reservoir releases, reservoir spills and
natural runoff and sediment loading from downstream watershed areas, should continue to exert a large
influence on the quantity and types of wetlands downstream of Dam Site IV. Even if the amount of water
flowing over the beaver dams is altered by reservoir construction, the depth of water ponded behind the
dams should not significantly change.
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Cohoke Creek Watershed Area (1994 Aerial Photography)
Figure omitted
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Cohoke Creek Between Dam Site IV and Cohoke Millpond Highlighting Some Ponded Areas
Due to Beaver Dams (1994 Aerial Photography)
Figure omitted
5.7 WATER TEMPERATURE MAINTENANCE
The DEQ VWP Permit requirements are designed to maintain suitable water quality conditions in Cohoke
Creek downstream of Dam Site IV. The VWPP specifically requires that releases from King William
Reservoir to Cohoke Creek not cause the violation of water quality standards for dissolved oxygen,
temperature, or pH. The RRWSG has proposed in its Joint Permit Application that intakes for the
downstream release of water will be located at elevation 80, 65 and 45 feet msl. This multi-level release
capability will provide added flexibility to ensure that downstream water quality is protected.
5.8 COMPARISONS TO RELEASE FROM OTHER RESERVOIRS
The degree of protection afforded the downstream Cohoke Creek ecosystem by the VWP Permit
minimum release provisions is more evident when they are compared to release schedules established for
already permitted reservoirs in Virginia and North Carolina. The average median monthly release of 4.0
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mgd represents 73 percent of the estimated 5.5 mgd average flow at Dam Site IV. As portrayed in the
following graph, all of these releases requirements, on a percentage of average flow basis, are
substantially below what VDEQ has required for Cohoke Creek. To our knowledge, the most recent
Corps permit issued in Virginia or North Carolina for a major water supply reservoir was in February
1997, when the Corps issued a permit to the City of Wilson, North Carolina, for expansion of Buckhorn
Reservoir. The City of Wilson permit required reservoir releases representing only 1 to 5 percent of
average flow at the new dam site.
Permitted Release Requirements for Reservoirs in Virginia and North Carolina
70
60
50
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King William Beaverdam Coddle Creek Hunting Run Cedar Run Hillsborough
(RRWSG, VA) Swamp (Cabarrus (Spotsylvania (Fauquier Reservoir
CoTtJ'vI) County, NC) County, VA) County, VA) (Hillsborough,
NC)
5.9 STREAM CORRIDOR PRESERVATION
The RRWSG will ensure the downstream ecosystem is preserved through acquisition of the streambed
and an upland buffer. A set-aside of the stream corridor and surrounding 200-foot upland corridor is
proposed from Cohoke Millpond to Dam Site II. Also the entire stream corridor and uplands up to
elevation 96 feet above mean sea level is proposed as a set-aside from Dam Site II to the currently pro-
posed Dam Site IV. These measures will establish a continuous wildlife preservation corridor between
Dam Site IV and Cohoke Millpond. These areas include over 800 acres including 6.4 miles of stream
corridor. This effort will preserve and protect wetlands and surrounding uplands below Dam Site IV.
Preservation of this area will allow natural succession of cut areas and immature forests to their mature
state, resulting in improved habitat for many wildlife species. The proximity of these preserved forest
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areas to the open water communities in King William Reservoir will also enhance habitat diversity and
provide added wildlife benefits to the existing downstream ecosystem.
Under the terms of agreement between the RRWSG and King William County, the host jurisdiction, the
County has a right to pursue a future dam downstream of the currently proposed dam site (KWR-IV).
Although this right is preserved in the host agreement, the RRWSG is unaware of any plans to develop a
downstream impoundment on Cohoke Creek. King William County is currently slated to receive an
allotment of the reservoir's safe yield to meet their projected water needs; therefore, if expansion of the
King William Reservoir is pursued, it would occur well in the future. If the County ever desires to build
another impoundment in Cohoke Creek downstream of Dam Site IV, they would be subject to the same
public interest review process and regulatory approvals that the RRWSG has faced.
5.10 CONCLUSION
King William Reservoir has been planned exercising the principles of avoidance and minimization. First,
the reservoir was located within a stream segment where wetlands are already separated from direct
connection to the Pamunkey River by the existing Cohoke Millpond. Efforts were then made to minimize
wetland impacts by twice relocating the dam site farther upstream in response to federal agency
recommendations. The effect of moving the dam site upstream to the currently proposed Dam Site IV
from the originally proposed Dam Site I was to reduce wetland impacts by 216 acres (or 33 per-cent), but
involved sacrificing 9 billion gallons (or 42 percent) of the original storage capacity.
With VDEQ-mandated median monthly flow releases, the substantially reduced King William Reservoir
(i.e., Dam Site IV) will adequately protect the downstream Cohoke Creek ecosystem from reasonably
foreseeable adverse effects. This conclusion is supported by the following key points as well as other
rationale covered in this report:
The monthly varying release requirements would preserve at least 73 percent of estimated
average flow at Dam Site IV, at least 85 percent of average flow into Cohoke Millpond, maintain
seasonality associated with pre-project flows, and would even preserve more streamflow than
would naturally occur during drought conditions.
Even under 2040 to 2050 conditions, when RRWSG demands are projected to require full use of
King William Reservoir safe yield, the reservoir would still be full in 59 percent of the simulated
months, thereby providing frequent opportunities for storm events to cause high flow pulses in
Cohoke Creek. The reservoir would be full even higher percentages of time during the decades
before the reservoir's full capacity is needed.
An additional 7.4 square miles of watershed area draining to Cohoke Creek between Dam Site IV
and the Cohoke Millpond dam would provide runoff and sediment loading that would
substantially augment downstream flows and aid in wetland maintenance beyond the protection
afforded by reservoir releases.
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MRNIl
COHOKE CREEK DOWNSTREAM
PROTECTION
The RRWSG has made a generous proposal for downstream corridor preservation that will
protect wetlands and surrounding uplands in a continuous wildlife preservation corridor between
Dam Site IV and Cohoke Millpond. A very high level of downstream protection will be provided
with this reservoir project, and certainly more than typically required for other such projects in
the Mid-Atlantic region. Although King William County has a right to pursue a future dam
downstream of the currently proposed dam site (KWR-IV) under the terms of the host agreement,
the RRWSG is unaware of any plans to develop a downstream impoundment on Cohoke Creek.
KING WILLIAM RESERVOIR MITIGATION PLAN
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SECTION 6.0
PIRNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
6.1 INTRODUCTION
Stream and riparian corridor mitigation to offset anticipated impacts to the main stem of Cohoke Creek
and its tributaries has been discussed periodically on a preliminary level since 1997. This component of
the reservoir mitigation plan strives to achieve, at a minimum, a 1:1 mitigation to impact ratio on a stream
order to stream order basis. The U.S. Army Corps of Engineers (Corps) and the U.S. Fish and Wildlife
Service (USFWS) have previously acknowledged this ratio.
A summary of the expected impacts to streams and riparian corridors by the prepared reservoir is
provided in Table 6-1.
Table 6-1:
King William Reservoir Stream Impacts
Stream
Order
First
Second
Third
Totals
Miles
14.5
3.0
3.5
21.0
Over the past few years, mitigation for impacts to streams has received increasing attention by state and
federal agencies on a national level. On June 14, 2001, the Norfolk District Corps issued a one page
''Draft Guidance for Stream Impacts" (14 June 2001). According to this memorandum, stream mitigation
options can include stream buffers, water quality improvement measures, and in-stream treatments and/or
bioengineering measures (generally excluding stormwater ponds). The Norfolk District has not, however,
released a final stream assessment protocol or a specific/preferred methodology to quantify the amount or
type of mitigation required to offset project impacts in the coastal plain. Accordingly, no State or Norfolk
District-specific stream mitigation guidance for coastal plain systems in Virginia was available at the time
that this component of the reservoir mitigation plan was prepared.
The stream and riparian corridor component is based on past project-specific correspondence with the
permitting agencies, professional experience, available literature, and the Corps Wilmington, NC
District's, "Stream Mitigation Guidelines" (June 2003). This guidance was prepared by a multi-agency
workgroup consisting of representatives from Corps, Wilmington District, North Carolina Division of
Water Quality (DWQ), Region IV U.S. Environmental Protection Agency (USEPA), Natural Resources
Conservation Service (NRCS) and the North Carolina Wildlife Resources Commission (WRC). The
Wilmington District Corps Guidelines were used to develop the stream mitigation plan since this District
KING WILLIAM RESERVOIR MITIGATION PLAN
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MMCOLM
PIRN!
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
6
was the closest to the Norfolk District with guidelines that apply to coastal plain stream systems with
similar geography to systems in Virginia.
The stream and riparian corridor component provides conceptual information on the types and amounts of
stream mitigation proposed for the project. Final site designs will be based on detailed site assessments
that will more closely evaluate design parameters.
6.2 STREAM MITIGATION GOALS
The goals of the stream and riparian corridor mitigation component are to replace, to the degree
practicable, the functions lost by flooding portions of Cohoke Mill Creek and its tributaries. The
functions that are typically impacted with the loss of streams and riparian corridors include:
Stream Functions
Transporting water, sediment, and nutrients
Supporting aquatic and riparian habitat
Providing a corridor for movement of both aquatic and terrestrial species within the
watershed
Riparian Corridor Functions
Maintaining water quality
Stabilizing stream banks
Providing shade to keep the water temperature cooler
Supporting birds and terrestrial wildlife
Providing "detritus" in the aquatic food chain
The goal of the stream mitigation is to achieve the maximum level of improvement given the site-specific
constraints.
6.3 MITIGATION CREDIT CALCULATION
For this stream and riparian corridor mitigation component, three types of mitigation will be employed:
restoration, enhancement, and preservation. Because restoration, enhancement, and preservation
inherently address different aspects of stream stability and function, ranging from significant restoration
to more stable conditions to preserving the existing conditions, a credit schedule following that contained
in the Corps's guidance has been developed. The definitions, for the purposes of this component and the
baseline mitigation credits assigned to each, are provided below.
ป Restoration [1:1] - Includes restoring the appropriate geomorphic dimension (cross-section),
pattern (sinuosity), and profile (channel slopes). Includes new channel construction, etc. In most
cases this would include some degree of riparian preservation. One mile of restoration is equal to
one restoration mile-credit.
KING WILLIAM RESERVOIR MITIGATION PLAN
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STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Enhancement [1.5:1] - Includes stabilization of streambanks through sloping to restore the
appropriate dimension and vegetating a riparian zone (typically 50 feet from the bankfull
elevation) that is protected from livestock by fencing, and construction of structures for the
primary purpose of stream bank stabilization. Enhancement generally does not include
restoration of dimension, pattern, or profile. In most cases this would include some degree of
riparian preservation. One and '/2-mile of enhancement is equal to one enhancement mile-credit.
Preservation [2.5:1] - Includes placing a restrictive covenant or deed restriction on a riparian
buffer, typically, 50 feet from the bankfull elevation on either side of the channel. Two and '/2-
miles of preservation is equal to one preservation mile-credit.
The mitigation ratios presented herein represent a reasonable evaluation of the types and amounts of
mitigation that were deemed feasible and scientifically viable. The final mitigation credits assigned to
each stream segment will be based on the amount and type of mitigation proposed for each segment. For
example, we may propose 100 linear feet of stream mitigation credit for enhancement of 150 linear feet of
stream, or a ratio of 1.5:1; however, after a detailed assessment, we might determine that instead of
simple buffer enhancement with minimal bank stabilization, a higher level of enhancement or some
restoration is required. We may request to have this segment contribute credits at 1:1 or 150 feet of
mitigation credit. Because of these situations, this conceptual stream and riparian buffer mitigation
component of the reservoir mitigation plan needs to maintain flexibility in determining the most
applicable means of restoration or enhancement for each stream segment as additional information is
gathered in the stream assessment effort.
6.4 STREAM MITIGATION SITE SELECTION/ANALYSIS
A four-tiered approach to the site selection process was developed.
following locations were considered:
Mitigation opportunities at the
Tier 1 - Downstream from the King William Reservoir on Cohoke Creek;
Tier 2 - The 200-ft buffer around the reservoir;
Tier 3 - Streams within or adjacent to the wetland mitigation sites; and
Tier 4 - Streams in the USGS HUC (02010106) but outside of the project area.
This process resulted in identifying on-site and off-site elements for incorporation into the stream and
riparian corridor mitigation component. On-site mitigation will include preservation of all stream
corridors contained in Tiers 1 and 2 on the above list. After on-site alternatives were exhausted, the Tier
3 sites were considered. This search was focused on potential stream mitigation opportunities on and
adjacent to the proposed wetland mitigation sites discussed in Section 4. The fourth tier of evaluation
resulted in identifying tentative sites in the Green Springs National Historic Landmark District, located
near Boswells Tavern in Louisa County, Virginia.
The preliminary identification of potential stream restoration or enhancement focused on first or second
order streams with degraded banks or streambeds and streams with no forested buffers or poor quality
forested buffers. The preservation component of the stream and riparian corridor mitigation component
focuses on preserving existing forested buffer on first and second order streams as well. Protection and
KING WILLIAM RESERVOIR MITIGATION PLAN
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MA1C3OLM
PIKNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
restoration of headwater streams is recognized as a critical element to watershed rehabilitation. The most
benefit from this stream and riparian corridor component can be realized by using a watershed approach.
Table 6-2 summarizes the number of sites and the geographic extent of the search for feasible and
scientifically viable stream mitigation sites.
Table 6-2:
Stream Mitigation Site Analysis
County
King William County
New Kent County
Hanover County
Caroline County
Louisa County
Spotsylvania County
James City County
Gloucester County
TOTAL
No. of Sites
Identified *
16
9
14
1
24
10
5
2
81
No. of Sites Field
Investigated **
8
0
1
0
11
0
0
0
20
No. of Sites Agency
Investigated
4
0
1
0
4
0
0
0
9
* Landowner permission to access the sites was requested for each identified site.
** Site visits were conducted following landowner consent.
The following summarizes the stream mitigation proposed for each of these tiers. Figures 6-1 through 6-
lld contain location maps and selected photos of the proposed stream and riparian corridor mitigation
sites. Table 6-3 provides a breakdown of the amounts and types of stream mitigation prepared for each
site or area.
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TABLE 6-3:
STREAM MITIGATION SUMMARY (miles)
Site
CohokeCrk and Tribl from Dam to Cohokt Mill Pond . :
Cohoke Crk and TribJ Mile-Credit Subtotal
ReMrvoIr Tributaries In the Buffer ,
Reservoir Tributary Mile-Credit Subtotal
York Rner MiUation Bank (Bleak Hill/Fern' Farm)
Burlington Farm
Davis Property
Gulasky
Island Site
sland/Rice Offsite
King William Farm
Lanesville1
Meadow Farm Site "C"
Rice Property '
Terrel Property
Townsend Property
Local Subtotal ~" ' " !
Local Mitigation Site Mile-Credit Subtotal
.ouisa County Sites
Loidia Subtotal
Louiia Min'cation Site Mile-Credit Subtotal
Grand Total MUes
Grand Total Milt-Credit!
Restoration
1st
0,0
0.0
10
09
14
03
36
''OX)
'3.6
36
2nd
0.0
bo
>'' 0.0
" 00
ro.o
oo
3rd
00
0.0
08
"' 0.8
00
0.8
08
4th
: o.o
- 0.0
0,0
.-' 00
, 0.0
00
>5th
0.0
"0.6
0.0
0.0
0.0
00
Subtotal
, 0.0
00
'''. " 00
00
10
00
00
09
1 4
00
08
00
03
00
00
00
>/ป44
44
00
0.0
00
4.4
44
Enhancement
1st
0,0
0.0
04
1 5
01
', 2.6
90
: 9.0
11.6
7.3
2nd
0.0
o.o
04
- " 0.4
20
its
'-2.4
i 6
3rd
""-'oo
- o.o
09
. 0.9
'-' oo
0.9
06
4th
-. o.o
0.0
0.0
0.0
0.0
00
>5th
00
00
00
00
.' 0.0
00
Subtotal
'.t]6
00
**'-'
0,0
00
00
04
00
00
00
28
00
00
0 1
00
00
00
"?>*" 3.3
22
110
li.o
73
.-"lia
96
Preservation
1st
37
'' 0.1
01
05
08
02
02
13
08
02
"''41
O.'O
7.9
32
2nd
0.9
0,1
03
06
1 1
20
' 0.0
3.0
1 2
3rd
,2.1
0.0
15
1 7
08
4.0
0.0
6.1
24
4lh
' 00
00
00
00
00
00
>5th
0.0
0.0
08
. 0.8
0.0
" 6.8
03
Total Mitigation Weighted Net Difference (Restoration Net + Enhancement Net + Preservation Net Mile-Credit)
Subtotal
6.7
27
02
01
15
01
05
08
02
1 7
08
05
19
1 9
08
02
10.8
43
00
0.0
00
- 17.7
7 1
Li
Total Miles
67
'; 0.2
; -?>
25
05
05
17
1 t
45
15
05
23
19
08
02
' 18*3
-;,|fSrTJ
11 0
'v'-. " * 11.0
n-itฃ-f?T- '.,
'*!# ' ;f
-\f ' 36.4
J?/,-"" >.'"''' ,'".-, "
^''-fiv^'v
g , ,*?*'" -."
Some portion of the streams on these site form property boundaries Easements will be obtained as part of the mitigation plan in order to establish the necessan' mitigation objectives
'Proposed Credit Ratio for Restoration
Apply this restoration credit ratio to mile-credit subtotals (vs each
stream order)
'Proposed Credit Ratio for Enhancement
Apply this enhancement credit ratio to mile-credit subtotals (vs each
stream order)
Proposed Credit Ratio for Preservation
Apply this preservation credit ratio to mile-credit subtotals (vs each
stream order)
(If box checked, Mititation Credit Multiplier must be fill out on a
stream order basis, above)
u..
Restoration includes restoring the appropriate geomorphic dimension (cross-section), pattern (sinuosity), and profile (channel slopes) Also includes
new channel construction
Enhancement includes stabilization of streambanks through sloping to restore the appropriate dimension and vegetating a riparian zone that is
protected from livestock by fencing, and construction of structures for the primary purpose of stream bank stabilization This does not include
restoration of stream dimension, pattern, or profile
December 2003
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MALCOLM
PIRNE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Tierl
Downstream Cohoke Creek
Mitigation here involves proposing 6.7 miles of first, second and third order stream corridor preservation.
It consists of a 200-foot buffer from the bankfull elevation on either side of Cohoke Creek from the
Cohoke Creek Mill Pond to the Dam Site II and of all land below the 96-foot contour from the Dam Site
II to the Dam Site IV (Figure 6-1). Under the terms of agreement between the RRWSG and King
William County, the host jurisdiction, King William County has a right to build a future dam downstream
of the currently proposed dam site (KWR-IV). Although this right is preserved in the host agreement, the
RRWSG is unaware of any plans to develop a downstream impoundment on Cohoke Creek. King
William County is currently slated to receive an allotment of the reservoir's safe yield to meet their
projected water needs; therefore, if expansion of the King William Reservoir is pursued, it would occur
well in the future. Construction of another dam would require permit approval from the Corps and the
State.
Total Tierl: 6.7 miles
Tier 2
Reservoir Tributaries
This includes approximately 0.2 miles of first order stream corridor preservation for all stream corridors
coming into the reservoir within the 200-foot reservoir buffer that will encompass the permanent pool
(Figure 6-1).
Total Tier 2: 0.2 miles
Tier3
York River Mitigation Bank
To date, the Bank has not finalized stream mitigation credits with the Mitigation Banking Review Team
(MBRT). The Bank operator will coordinate stream mitigation crediting with the MBRT following
applicable Corps and State guidelines. The mitigation credits presented in Table 6-3 are based on
conceptual information from the Bank's consultant, and may be modified following further field
investigations and MBRT review. Over 2.5 miles of stream mitigation are proposed within the Bank
(Figure 6-2a and 6-2c).
This site contains potential for significant channel restoration by realigning 0.9 miles of first order stream
through the middle of the proposed wetland creation area. Approximately 0.8 miles of preservation is
proposed for existing stream corridor that is forested (Figures 6-2a and 6-2b).
Burlington Farm
This site contains approximately 0.4 miles of first order enhancement in the form of riparian corridor
improvement and stream bank stabilization. In addition, 0.1 miles of first order stream corridor
preservation is proposed where adequate riparian buffer currently exists (Figures 6-3a and 6-3b).
KING WILLIAM RESERVOIR MITIGATION PLAN
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STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Meadow Farm
Approximately 0.3 miles of first order restoration, 0.1 miles of first order enhancement, and 1.9 mile of
first and second order stream corridor preservation are proposed for this site (Figures 6-3a and 6-3b).
Davis Property
Preservation of approximately 0.5 miles of existing first order stream corridor with a forested buffer is
proposed for this site (Figure 6-4a and 6-4b).
The Island
Approximately 1.4 miles of first order stream restoration is proposed for this site that will direct water
through the site in several channels. In addition, 0.2 miles of first order stream corridor is proposed for
preservation (Figures 6-5a and 6-5b).
Rice
Approximately 1.9 miles of second and fifth order stream corridor preservation are proposed for this site
(Figure 6-5 a).
Island/Rice Offsite
Approximately 2.8 miles of first, second and third order enhancement is proposed for these tributaries to
Moncuin Creek, which flows directly into the Pamunkey River. Both enhancement and preservation are
proposed for these stream corridors. There is a potential to use cattle exclusion fencing in this area as
well as streambank stabilization. Approximately 1.7 miles of third order stream corridor preservation is
proposed for this area (Figure 6-5a).
Lanesville
This site contains approximately 0.5 miles of first and second order stream corridor preservation
(Figure 6-6a and 6-6b).
King William Farm
This site contains potential for significant channel restoration by realigning 0.8 miles of third order
stream through the middle of the proposed wetland creation area. This action relocates the stream closer
to its natural location in the landscape. Additionally, approximately 0.8 miles of third order preservation
is proposed for existing stream corridor that contains forested buffer (Figure 6-7a and 6-7b).
Terrell
Approximately 0.8 miles of first order stream corridor preservation is proposed for this site (Figure 6-8).
Townsend
Approximately 0.2 miles of first order stream corridor preservation is proposed for this site (Figure 6-9).
Total Tier 3: 18.5 miles
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
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MALCOLM
PIRNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Tier 4
Louisa County
Approximately 11 miles of first and second order enhancement is proposed within the Hudson Creek
watershed in the Green Springs National Historic Landmark District in Louisa County (Figure 6-10).
The named tributaries to Hudson Creek are: Fielding, Givies, Bunch, and Wheeler Creek. Hudson Creek
flows to the South Anna River, a tributary to the Pamunkey River. Heavily eroded banks characterize
many of the stream corridors. They are cleared to the top of bank, and cattle have free access to the
streams. Mitigation on the Louisa County sites will focus on cattle fencing, enhancing riparian buffers,
and streambank stabilization primarily on first and second order headwater streams. Figure 6-1 la
provides a color infrared image of the Hudson Creek watershed and identifies the most probable locations
for performing stream and riparian corridor enhancement. Locations of photos of typical stream
conditions are also provided on this figure. The photos are contained in Figures 6-1 lb-1 Id.
Total Tier 4:11 miles
Grand Total: 36.4 miles
Table 6-3 provides a detailed accounting of all the stream mitigation credits proposed for this project.
Table 6-4 shows that approximately 36.4 miles of stream corridor restoration, enhancement, and/or
preservation are proposed in this reservoir mitigation plan to offset the impacts to the 21 miles of streams
on this project. Table 6-5 illustrates that, based on the approach and assumptions outlined above, the
mile-credits developed using the afore-mentioned mitigation ratios equal the miles of impact. Thus,
adequate stream corridor mitigation of the same order is proposed under this plan. As shown on Tables 6-
2 and 6-3, approximately 25.4 of the mitigation miles are in the Tier 1 through 3 sites and approximately
11 miles are located in Louisa County.
Table 6-4:
Stream Mitigation Miles1
Order
First
Second
Third
Fourth
Fifth
Totals
;" Restoration^-
3.6
0.0
0.8
0
0
4.4
jtfe Enhancement *
11.0
2.4
0.9
0.0
0.0
14.3
Jt^resCTvatiblit*^
7.9
3.0
6.1
0.0
0.8
17.7
Irbtal
22.5
5.4
7.7
0.0
0.8
36.4
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
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MAICOLM
PIRNIE
STREAM AND RIPARIAN CORRIDOR
Table 6-5:
Stream Impact vs. Mile-Credit Balance Sheet
Order !
First
Second
Third
Fourth
Fifth
Totals
Miles Impact
14.6
3.0
3.5
0
0
21.0
'Mile-Credits1
14.1
2.8
3.8
0.0
0.3
21.0
/ Credit Balance
(0.5)
(0.2)
0.3
0.0
0.3
(0.0)
1 Includes composite mile-credits from:
Restoration at a ratio of-
Enhancement at a ratio of-
Preservation at a ratio of-
1
1.5
2.5
6.5 COMPONENT IMPLEMENTATION
The stream and riparian buffer mitigation plan needs to maintain flexibility. Final plan development will
occur after permit issuance, and will incorporate the most current technology and state of the art stream
assessment and restoration techniques. Appropriate strategies for stream improvement within each of the
mitigation sites will be identified during detailed field assessments. However, the scope of the mitigation
plan will not be expanded beyond the original requirements. Implementation of the stream mitigation
plan shall be coordinated with the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, the
U.S. Environmental Protection Agency, the National Marine Fisheries Service, the Virginia Department
of Environmental Quality, and the Virginia Department of Game and Inland Fisheries.
Prior to submitting a final stream mitigation plan, a reach assessment using rapid assessment techniques
will be conducted detailing physical and biological impairments and plans for the extent of restoration,
enhancement and or preservation. Site assessments will be conducted using "Preliminary Watershed
Assessment" (Fischenich, 2000) or similar guidance. In addition, where practicable all restoration will be
conducted using reference reaches as described in the USDA Forest Service Manual, Stream Channel
Reference Sites (Harrelson, et.al, 1994). Stream classifications will be conducted using techniques
outlined in Rosgen (1996).
The buffer component of this reservoir mitigation plan focuses on preserving forested buffer on
headwater streams or restoring forested buffers that have been converted to pasture or cropland and on
installing cattle exclusion fencing on pasture where riparian buffers have been removed. The riparian
restoration will consist of planting native trees and/or shrubs at 8 to 15-foot spacing following NRCS
buffer restoration guidelines and/or other appropriate documents. Similar guidance will be followed for
placement of cattle exclusion fencing.
KING WILLIAM RESERVOIR MITIGATION PLAN
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PIRNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Stream hydrologic and physical assessment and restoration techniques will be consistent with accepted
engineering practices. Typical structures used for stream restoration will be employed. Examples of
some of these structures are shown below. Structures not shown here may also be used and not all those
shown here will necessarily be used.
Figure omitted
The proposed mitigation presented here is intended to optimize the feasible mitigation opportunities using
cost effective and proven methods. It is possible that other factors, such as land ownership and
constructability issues, may preclude some of the proposed sites from being available.
KING WILLIAM RESERVOIR MITIGATION PLAN
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MALOOIA1
PIRNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Figure omitted
Figure omitted
Figure omitted
Figure omitted
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PIRNIE
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
6.6 MONITORING AND DEED RESTRICTION
The stream mitigation segments will be monitored annually over a 5-year period. If stream mitigation
activities have been fully successful over the 5-year period and 2 bankfull events, it will be considered
successful. The types of monitoring will depend on the final design complexity for each reach. As
necessary, monitoring will include photos, monitoring plant survival, and channel stability.
To the maximum extent practicable, the mitigation segments and associated riparian corridors will be
protected in perpetuity through restrictive covenant or deed restriction.
6.7 SUMMARY
To the RRWSG's knowledge, the stream mitigation plan proffered is the most extensive compensation
package that has been developed for a Virginia coastal plain project. The mitigation proposal is within
Corps guidelines and provides required compensation. Impacts to 21 miles of streams caused by
construction of the King William Reservoir would be offset by 21 mile-credits (36.4 miles) of a
combination of stream and riparian corridor restoration, enhancement, and preservation on Cohoke Creek,
downstream of the reservoir, in riparian corridors within the 200-ft buffer around the reservoir, on the
wetland mitigation sites, and in the Green Springs National Landmark Historic District in Louisa County.
To a large degree, this stream and riparian corridor mitigation plan addresses restoring function to
channelized streams or streams that have had functions significantly impaired through past and present
agricultural and silvicultural practices.
The stream and riparian corridor mitigation component of this reservoir mitigation plan exceeds the 1:1
stream mitigation approach discussed in the past. The incorporation of 18.7 miles of restoration and
enhancement accounts for two-thirds of the mile-credits (14 mile-credits) proposed to offset the impacts
within the project area. The majority of the stream segments proposed for preservation are located within
the wetland mitigation sites, ensuring perpetual protection of corridors that reconnect the wetland and
stream systems to form extensive ecosystem complexes. The stream and riparian corridor mitigation
concepts presented in this section will restore/improve stream functions previously provided by the
stream and riparian corridors and to provide protection, in perpetuity, to less at-risk stream reaches.
Although no impacts to anadromous fish movement are expected to result from this project, the RRWSG
has volunteered to work with the Virginia Department of Game and Inland Fisheries (VDGIF) to provide
funding to restore anadromous fish passage on one or more priority streams in the York River Basin. The
USFWS has agreed that anadromous fish passage funding can be credited as stream mitigation to offset
the impacts within the reservoir project area. The stream mitigation proposal will be modified to include
the crediting for fish passage restoration once appropriate crediting for fish passage funding is
determined.
6.8 REFERENCES
Fischenich, C., 2000. Preliminary Watershed Assessment, EMRRP Technical Notes Collection (ERDC
TN EMRRP-SR-03), U.S. Army Engineer Research and Development Center, Vicksburg, MS.
KING WILLIAM RESERVOIR MITIGATION PLAN
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MAJJOOLjVi
PIRN!
STREAM AND RIPARIAN CORRIDOR
MITIGATION COMPONENT
Harrelson, C.C., C.L Rawlins, J.P. Potyondy. 1994. Stream Channel Reference Sites: An Illustrated Guide
to Field Technique. USDA Forest Service. General Technical Report RM-245.
Rosgen, D.L. 1994. A Classification of Rivers. Catena 22: 169-199.
U.S. Army Corps of Engineers (Corps), North Carolina Division of Water Quality, U.S. Environmental
Protection Agency, and North Carolina Wildlife Resources Commission. 2003. Stream Mitigation
Guidelines. April 2003.
KING WILLIAM RESERVOIR MITIGATION PLAN
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SECTION 7.0
MAlJOCXM
PIRNIE
FISH AND WILDLIFE HABITAT
MITIGATION COMPONENT
7.1 INTRODUCTION
The Regional Raw Water Study Group was created in the fall of 1987 to examine the long-term water
supply needs of the Lower Peninsula area of southeast Virginia and to develop a plan for meeting those
needs. Based on a practicability analysis of 35 water supply alternatives, the RRWSG selected the King
William Reservoir as part of an overall project that it determined to be the least damaging practicable
alternative for providing a 50-year, dependable public water supply. Through the Year 2050, the
RRWSG's projected water supply deficit can be met with the King William Reservoir.
The RRWSG's Reservoir Mitigation Plan is designed to compensate for the loss of acreage and function
of wetlands and to compensate for other environmental impacts including fish and wildlife habitat losses
in the project area. The Mitigation Plan represents the culmination of over ten years of agency
coordination and review and its successful implementation will assure that project impacts will be offset.
This program will achieve the RRWSG's goal of compensating for project impacts by establishing fully
functional wetland ecosystems and providing substantial mitigation for other potential environmental
impacts. The mitigation plan is unique and comprehensive.
The wetland mitigation component of the RRWSG's Reservoir Mitigation Plan is designed to compensate
for the loss of non-tidal, vegetated wetland and open water acreage that will be filled or inundated by the
King William Reservoir Project. An exhaustive search for suitable restoration, creation, and preservation
areas resulted in the identification of eleven primary compensation sites that have a high probability for
successful establishment and will provide valuable wetland habitat. To facilitate the development of a
successful compensation plan, a wetland compensation pilot study was completed in coordination with
federal and state agencies, and several subsequent draft versions of the wetland compensation plan were
submitted for agency review and comment.
This fish and wildlife habitat mitigation component of the RRWSG's Reservoir Mitigation Plan has been
developed to compensate for impacts to fish and wildlife habitat currently provided by the wetlands and
aquatic resources within the proposed project area. This plan component incorporates the habitat values
of the Wetland Mitigation Plan. It also includes lacustrine and shoreline wetland heibitat created by the
reservoir; wetland preservation; upland restoration and preservation; and compensation for the loss of
riverine habitat. These elements include restoring and preserving stream corridors, and providing for re-
establishment of anadromous fish passage in the York River Basin. Other potential elements, which
depend in part on the Pamunkey and Mattaponi Indian Tribes, include financial or other support for fish
hatcheries and wetland education programs on the Tribal lands.
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7.1.1 AVOIDANCE, MINIMIZATION AND COMPENSATION
The 1990 Memorandum of Agreement (MOA) between the USEPA and the Department of the Army
addresses the policies and procedures to be used in the determination of the type and level of mitigation
necessary to demonstrate compliance with the Clean Water Act Section 404(b)(l) Guidelines (Guidelines)
(USEPA and Army, 1990). Based on the Clean Water Act and the Guidelines, USCOE strives to achieve
a goal of no overall net loss of wetland values and functions by requiring mitigation for discharges of
dredged or fill material into these jurisdictional areas. Appropriate mitigation is determined by the
USCOE based on the values and functions of the aquatic resources impacted. Specific mitigation
requirements are defined by the mitigation sequencing rules.
The first sequencing step, avoidance, requires an evaluation of practicable alternatives by permit
applicants to confirm that the selected project will have the least adverse impact on the environment. The
second sequencing step requires permit applicants to make appropriate and practicable efforts to minimize
unavoidable impacts. Finally, permit applicants must provide compensation for the remaining wetlands
impacted by discharges.
The RRWSG exercised the principles of avoidance and minimization by evaluating more than 35 water
supply alternatives and choosing the King William Reservoir project, avoiding other alternatives that
either were not practicable or had greater impacts. Three reservoir alternatives were chosen for detailed
study in the Corps of Engineers, Final Environmental Impact Statement (FEIS): Ware Creek Reservoir,
Black Creek Reservoir, and King William Reservoir (USCOE, 1997).
As explained in the FEIS, Ware Creek Reservoir was considered the most damaging of the three
alternatives, by impacting water quality, diverse wetland systems, anadromous fish, and other wildlife
habitats. The Black Creek Reservoir project would impact a smaller area of wetlands; but it would
provide a far smaller water supply yield than the King William Reservoir project, requiring excessive
reliance on groundwater in a groundwater management area already under stress. It also would require
flooding a number of homes. Finally, the Black Creek project does not have support of the host
community, New Kent County, which has veto authority under Virginia's "local consent" laws, and
therefore it is not available to the RRWSG. Therefore, the RRWSG selected the King William Reservoir
project, as the least damaging, practicable alternative.
To minimize the impacts of wetlands losses, the King William Reservoir site was located within a stream
segment where wetlands are already disconnected from the Pamunkey River by the existing Cohoke
Millpond. The dam site was also relocated upstream from the original proposed site (Dam Site I) to Dam
Site IV, to reduce wetland impacts by 216 acres.
Proposed compensation for the unavoidable loss of wetlands is described in Section 4. To guide the
selection of mitigation sites, a prioritized list of desired characteristics was established which reflects the
mitigation priorities of the USCOE, USEPA, and the U.S. Fish and Wildlife Service (USFWS). The
wetland mitigation plan is designed to meet the federal and state policy of no net loss of wetland acreage
and functions.
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7.1.2 PURPOSE OF THE FISH AND WILDLIFE HABITAT COMPONENT
The Fish and Wildlife Mitigation identifies the methods and strategies that will be employed to offset
impacts to fish and wildlife habitat in the project area. These methods and strategies incorporate the goal
of "no net loss" of wetland acreage and function along with mitigation for other environmental impacts of
the project. Toward that end, the KRWSG has identified over 806 acres of potential wetland habitat
restoration and creation areas within the York and Rappahannock River basins that will be used to offset
the loss of 403 acres of vegetated wetlands within the reservoir pool area. The mitigation areas also
include preservation of more than 300 acres of existing wetlands adjacent to the wetland mitigation sites.
Preservation of these existing wetlands provides additional compensation over and above the 2:1
restoration/creation commitment.
As discussed in Section 4 the types of proposed wetland mitigation include restoration and creation.
Wetland restoration will allow for the return of prior converted (PC) croplands to their former wetland
character and function. Wetland creation includes the establishment of wetlands in areas! where
functional wetlands did not previously exist. If, during the mitigation plan implementation, site
restrictions or construction limitations result in a reduction of the acreage for some primary mitigation
sites, the development of contingency sites will be used to achieve the 2:1 compensation goal and to
satisfy the accompanying objective of providing in-kind wetland replacement at a minimum ratio of 1:1
for each vegetated cover type affected.
The 1,526-acre reservoir will create lacustrine open water habitat and various associated habitat types
along the shoreline. As demonstrated in the Habitat Evaluation Procedure (HEP) study, successful
implementation of the Reservoir Mitigation Plan will more than offset the wetland habitat losses from the
proposed project (Malcolm Pirnie, 1999). Additional functional analysis (provided in Section 8) indicates
that the functions lost within the impact area will be more than compensated for by the gains from the
reservoir and mitigation sites.
The fish and wildlife habitat mitigation component also includes approximately 2,900 acres of upland
restoration and preservation to offset impacts associated with the conversion of uplands to open water
areas within the King William Reservoir pool. An upland buffer will be established around the reservoir
pool, and upland areas will be restored and/or preserved as part of the buffer around wetland mitigation
sites.
Mitigation for aquatic ecosystem/habitat impacts will include at least 21 miles of stream restoration and
preservation to offset impacts to small streams in the project area. Stream corridor
restoration/preservation areas have been identified in the York River watershed (Section 6). Several of
the wetland mitigation sites offer stream corridor restoration and preservation opportunities. The
RRWSG also has volunteered to work with the Virginia Department of Game and Inland Fisheries
(VDGIF) to re-establish fish passage to one or more historic anadromous fish spawning areas in the York
River Basin. Improvements to the Pamunkey and Mattaponi Indian Reservations' fish hatcheries, and
support for Tribal wetland education programs are also being investigated. The elements of the
Mitigation Plan are summarized in Table 7-1.
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TABLE 7-1
Mitigation Components and Benefits
Wetland and Aquatic Resources
806 acres of restoration/creation provided by the wetland mitigation sites
Provides 2:1 compensation
1:1 replacement by cover type
Provides wetland functional replacement
Offsets "lag time" for wetland establishment
36.4 miles of riparian corridor restoration and stream enhancement
Fully compensates for 21 miles of impact
Other Components
300 acres of wetland preservation adjacent to the mitigation sites
1,251 acres of open water created by the reservoir
186 acres of preservation of downstream wetlands
322 acres of potential shoreline wetland and shallow water creation
Restoration and preservation of wetlands associated with stream corridors
Structural and engineering design to minimize impacts from intake
Anadromous fish passage
Hatchery Improvements
River monitoring
Upland Habitat
1,900 acres of reservoir buffer area
700 acres of buffer area for the wetland compensation sites
620 acres of preservation downstream of the dam
Endangered Species?
Avoidance
Pogonia Set-Aside Area
River Monitoring
Construction Impacts',"
Best Management Practices
Water Supply
Host Community Benefits
Recreation Benefits
Conservation of Large Expanses of Wetland/Upland Complexes
Preserved in Perpetuity
Net Wetland Gain
King William County has a right to pursue a future dam downstream of the currently proposed dam site (KWR-IV). However, the
RRWSG is unaware of any plans to develop a downstream impoundment on Cohoke Creek. The County is slated to receive an allotment
of the reservoir's safe yield to meet their projected water needs; therefore, if expansion of the reservoir is pursued, it would occur well in
the future. Construction of another dam would also require permit approval from the Corps and the State.
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FISH AND WILDLIFE HABITAT
MITIGATION COMPONENT
7.2 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES
7.2.1 WETLANDS WITHIN THE RESERVOIR POOL AREA
Construction and impoundment of the King William Reservoir will fill or inundate approximately 403
acres of non-tidal, vegetated wetlands and 34 acres of open water, in the Cohoke Creek watershed.
Wetlands at the reservoir site have been identified and delineated using the criteria described in the
Environmental Laboratory 1987, and classified according to the system published in Cowardin et al.,
1979. Several additional analytical techniques also have been employed to assess the functions and
values currently provided by the wetlands (and uplands) in the area to be inundated, as described in this
document.
Typical species found in non-tidal, palustrine forested wetlands at the King William Reservoir site
include red maple (Acer rubrum), green ash (Fraxinus pennsylvanicd), swamp chestnut oak (Quercus
michauxii), sycamore (Platanus occidentalis), sweet gum (Liquidambar styraciflua), slippery elm (Ulmus
rubra), and river birch (Betula nigra). Dominant species in palustrine scrub-shrub wetlands include
smooth alder (Alnus serrulata), wax myrtle (Myrica cerifera), silky dogwood (Cornus amomuni), black
willow (Salix nigra), buttonbush (Cephalanthus occidentalis), and various young maples, ashes, and
gums. Dominant species in palustrine emergent wetlands at the site include sedges (Carex spp.), Soft
rush (Juncus effusus), arrow arum (Peltandra virginica), smartweeds (Polygonum spp.), pickerelweed
(Pontederia cordata), and several varieties of ferns. Palustrine open water wetlands are also located in
the reservoir area.
The wetland types being impacted in Cohoke Creek are common along freshwater Coastal Plain
tributaries. The 437 acres of non-tidal vegetated wetlands and open water that would be inundated by the
reservoir represent 4 percent of the estimated 10,942 acres of non-tidal wetlands in King William County,
according to The Virginia Nontidal Wetland Inventory (VDCR, 1991). The total non-tidal wetlands in
Virginia Coastal Plain jurisdictions, defined by the USGS as those jurisdictions in which at least half of
the jurisdiction's area is within the Coastal Plain boundary, are approximately 256,948 acres. The
wetland estimates for King William County and the Virginia Coastal Plain as a whole were derived from
NWI mapping which has a pronounced tendency to underestimate actual wetland acreage when compared
to field verification. The VDCR Report indicates that the counties surrounding King William also have
numerous acreages of non-tidal palustrine wetlands; thereby, emphasizing the commonality of Cohoke
Creek within the region.
7.2.2 WETLAND EVALUATION TECHNIQUE
In April 1993, a wetland evaluation was completed for wetlands in the impoundment area of King
William Reservoir (KWR-II configuration). The USCOE's Wetland Evaluation Technique (WET) was
utilized to assess the functions and values of the wetlands at the proposed reservoir site (Adamus et al.,
1987; Adamus et al., 1991). WET is an approach to wetland evaluation which is based on predictors of
wetland functions that can be gathered quickly. WET estimates the probability that particular functions
will occur in a wetland area and provides an estimate of the importance of those functions. A detailed
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discussion of the methodology and results of this analysis are contained in Appendix II-1 of Report D
(Volume II) to the Corps of Engineers' Final Environmental Impact Statement (USCOE, 1997).
For purposes of this analysis, the impoundment was considered the assessment area and the impact area.
Therefore, the WET analysis provides an assessment of the palustrine wetland complex as a whole.
Because the palustrine system consists of many different types of wetlands, results from the evaluation of
any particular wetland site may be different from the overall results of the analysis.
Table 7-2 summarizes the results of the WET analysis for the KWR-II palustrine wetlands. The results of
the WET analysis indicate that the palustrine system has a high probability of being effective in providing
floodflow alteration, sediment stabilization, sediment/toxicant retention, and wildlife habitat. It has a
moderate probability of providing groundwater discharge and production export functions. It received
low scores for groundwater recharge, nutrient removal/transformation, and aquatic diversity/abundance.
7.2.3 EVALUATION FOR PLANNED WETLANDS
A second analytical methodology that was employed in the functional assessment of the wetland impacts
is the Evaluation for Planned Wetlands (EPW) methodology, developed by Environmental Concern, Inc.
(Bartoldus et. al., 1994), which also was applied to the wetlands in the KWR II project area. The EPW
format provides a quantitative evaluation of wetland values through analysis of the following six wetland
functions:
Shoreline bank erosion control
Sediment stabilization
Water Quality
I" I Fish
f Wildlife
t i
Uniqueness/Heritage
In EPW, specific physical, chemical, and biological elements of the wetland or landscape are identified.
These elements are quantified by their relationship to a particular function and are combined in
assessment models to derive Functional Capacity Indices (FCIs). FCIs are multiplied by the size of the
assessed wetland to calculate Functional Capacity Units.
The results of the evaluation indicate that the existing wetlands provide a high degree of sediment
stabilization and water quality functions and a moderate degree of wildlife and fish functions. A full
description of the EPW study is presented in the FEIS (USCOE, 1997).
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TABLE 7-2
Summary of Wet Analysis Results
King William Reservoir Dam Site II Wetlands
Function/Value
Groundwater Recharge
Groundwater Discharge
Floodflow Alteration
Sediment Stabilization
Sediment/Toxicant Retention
Nutrient Removal/Transformation
Production Export
Wildlife Diversity /Abundance
Wildlife Diversity/ Abundance (Breeding)
Wildlife Diversity /Abundance (Migration)
Wildlife Diversity /Abundance (Wintering)
Aquatic Diversity/ Abundance
Uniqueness/Heritage
Recreation
- -, , 0 '-,,-.. V ป - '*' f~
Evaluation Criteria
Social :
Significance-
M
H
M
M
M
H
*
H
*
*
*
M
H
L
Effectiveness
L
M
H
H
H
L
M
*
H
H
H
L
*
*
,. / / .v' T- "
Opportunity
*
*
M
*
H
H
*
*
*
*
*
*
*
*
Note: "H" = High
"M" = Moderate
"L" = Low
"*" = Functions and values are not evaluated by the WET program.
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PIRNIE
FISH AND WILDLIFE HABITAT
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7.2.4 HABITAT EVALUATION PROCEDURES GROSS LOSSES ANALYSIS
A multi-agency team has analyzed the project area of the King William Reservoir using a recognized
method of habitat analysis developed by the U.S. Fish and Wildlife Service, the Habitat Evaluation
Procedures (HEP). HEP is a method developed to quantify changes to the quality of a particular habitat
as a result of land and water development projects. The habitat value is measured in Habitat Units (HUs),
which result from determining the habitat quantity (acreage) and quality for selected species of fish and
wildlife. The habitat quality is expressed in the form of a wildlife species Habitat Suitability Index (HSI)
that measures suitability of a habitat. HEP is based on the assumption that at the species level, the value
of the habitat can be described by a set of measurable habitat variables that are important for the species
(Stiehl, 1995). Current habitat value is measured in the field to determine baseline conditions and then
projected to determine future conditions under various assumptions. Habitat value lost by the
construction of the project can be determined over the designated life of the project.
For each evaluation species chosen, a Habitat Suitability Index (HSI) model was used to guide the
variables measured in the field, such as average shrub height or percent of tree canopy from mast
producing species. These measurements were then put into a model to calculate an HSI value between 0
and 1.0 for a determination of habitat quality in the study area for each species. Once the HSI value was
determined for each species in a specific cover type, the area of available habitat was used to calculate
HUs according to the following formula:
HU = HSI x Area
Habitat value, measured in HUs, can be calculated to determine baseline conditions in the proposed
reservoir area, and then projected through future conditions, based on stated assumptions.
The KWR HEP study was conducted over a 3-year period by an interagency team of wildlife specialists
involved in the regulatory process for the reservoir. Team members included representatives from the
USFWS, USCOE, USEPA, Virginia Department of Environmental Quality (VDEQ), Newport News
Waterworks, and Malcolm Pirnie. Dean Stauffer with Virginia Tech was included in early 1997 as a HEP
expert to assist team members. The team cooperatively established working procedures and decisions
throughout the study were made by consensus. The team determined the main objectives of the KWR
HEP study to be:
Quantify aquatic and terrestrial habitat losses, for selected species, in the study area as a result of
reservoir construction.
Guide the types of mitigation required to compensate for habitat losses in the study area.
Provide a tool for mitigation plan habitat evaluation.
The first objective focused on a quantification of the habitat values lost as a result of project
implementation. This analysis, termed the gross losses, was based on the assumption that the reservoir
will provide no habitat value. The results provided a worst-case scenario of habitat loss. This allowed the
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Mitigation Team to identify the greatest amount of mitigation that could be required to offset the loss of
habitat for wetland species in the reservoir pool area.
The area of the HEP study was defined to be the reservoir pool area for KWR-IV. Using existing data,
mapping, photography, and field verification, cover types were delineated throughout the study area.
Cover typing allowed for the delineation of habitat types and the selection of evaluation species.
Evaluation species were selected to represent habitat features used by a group of species. The HEP Team
reached consensus on the selection of the following 12 evaluation species:
Beaver
Pileated Woodpecker
Brown Thrasher
Pine Warbler
" Field Sparrow
" Red-spotted Newt
Gray Squirrel
Redfm Pickerel
Great Blue Heron
Wood Duck
Mink
Yellowthroat
HSI models were obtained for each evaluation species and models were modified to reflect conditions in
the study area. For some species, only a specific life stage or habitat requirement was selected for
analysis. For example, only brood cover habitat suitability was assessed for the Wood Duck and only
foraging habitat was assessed for the Great Blue Heron. HSI models for the Yellowthroat and the Redfm
Pickerel were adapted from other published species models.
Following the selection and modification of HSI models, the HEP Team conducted field surveys during
July 1996. The field team collected species variable data throughout the KWR-II project area,
concentrating below the proposed pool elevation, the 96-foot contour. A total of 266 sample transects and
plots were taken throughout the various habitat types. When Dam Site IV, which is approximately 6,800
feet upstream of the KWR-II Dam Site, was proposed in January 1997, the Team decided to use the full
field data set for analysis of the KWR-IV project area, even though some of the sample points were no
longer in the pool area. Sample data taken from upstream and downstream of Dam Site IV showed little
variability.
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As detailed in the HEP Report (Malcolm Pirnie, 1999), HSI values were then calculated by applying the
field data to the evaluation species models. Once the HSI was determined for each species, the area of
available habitat was used to calculate HUs. Both baseline and future HUs were determined for the study
area. Baseline HUs are used to describe the existing ecological conditions and provide a reference point
from which impacts of the proposed alternatives can be compared (Target Year 0). Future HUs were
determined by predicting the total amount of available habitat and the HSI values for target years (TY) 1,
5, 20, 40, and 50. TY1 represents the first year after the beginning of project construction, TY50 is the
designated end of the project evaluation period, and TY 5,20, and 40 were selected as intervals.
Future HUs were calculated for the study area under two scenarios, the "with project" scenario, assuming
that the project is constructed, and the "without project" scenario, assuming that the project is never
constructed. Results were then annualized over the study life to calculate Average Annual Habitat Units
(AAHUs). AAHUs are used to compare habitat value under one scenario versus another. The gross
losses analysis was designed to determine the overall losses for selected species under theoretical worst
case conditions, assuming that no habitat value would be gained if the project were implemented. In
reality, of course, the open water and shoreline wetlands of the reservoir will provide habitat for many of
the evaluation species. However, by calculating gross losses in the project area, the team could identify,
under hypothetical maximum impact conditions, the greatest amount of mitigation that even theoretically
might be required to offset losses in the project area.
Table 7-3 presents the results of the gross losses analysis for the KWR-IV pool area in terms of AAHUs.
These results indicate that the reservoir pool area provides valuable habitat for wetland, upland and mixed
cover type species. While HU changes cannot be directly compared between species, relative habitat
losses can be assessed. The Red-spotted Newt, which uses both upland and wetland forested habitat, and
thus the largest amount of habitat in the project area, incurs the largest habitat loss. The Brown Thrasher,
which prefers later successional logged areas, shows the least amount of habitat loss. There is relatively
little of this type of habitat in the study area.
The remainder of the HEP study evaluated the habitat gains provided by the open water habitat of the
reservoir and potential project mitigation. This evaluation fulfilled the remaining two objectives of the
HEP study. A discussion of the habitat value of the proposed mitigation as determined by the HEP study
is provided later in this section.
7.2.5 PIPELINE
There are approximately 60 potential stream/wetland area crossings, encompassing approximately 6 acres
of vegetated wetlands and 1 acre of open water, along the 13.2 miles of pipeline for the King William
Reservoir. This estimate is based on the proposed pipeline route from the Mattaponi River to the
reservoir and from the reservoir to the Diascund Creek Reservoir basin. Approximately half of the
affected areas would be palustrine forested, broad-leaved deciduous wetlands. The estimated impact area
for the proposed pipeline route represents a worst-case scenario, because portions of the pipeline may be
re-routed during final design to avoid wetland impacts.
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TABLE 7-3
Gross Losses in the
KWR-IV Reservoir Pool Area
HEP Species
Beaver
Mink
Great Blue Heron
Wood Duck
Pileated Woodpecker
Gray Squirrel
Red-spotted Newt
Pine Warbler
Brown Thrasher
Field Sparrow
Yellowthroat
Redfm Pickerel
-';;_, AAHU :
With Action*
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
AAHU
Without Action
538.1
675.3
133.0
72.0
454.7
425.6
686.8
280.5
34.5
125.8
132.6
124.5
,; ,/_ Gross '-'
, "' Units ' '"''
-538.1
-675.3
-133.0
-72.0
-454.7
-425.6
-686.8
-280.5
-34.5
-125.8
-132.6
-124.5
Note: * To calculate gross impacts, the pool area was assumed to
have no habitat value for the with action condition.
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After construction, wetlands will be restored to their original limits, but reforestation along the pipeline
route will be suppressed to maintain the right-of-way. Thus, pipeline route maintenance will convert a
maximum of 3.5 acres of wetland habitat from forested to scrub-shrub/emergent habitat. Net wetland
acreage is not expected to be affected.
The pipeline also will cross under Cohoke Creek and the Pamunkey River. The crossings will be made
using directional drilling techniques. This will avoid disturbance to the bottom substrate and adjacent
wetlands.
7.2.6 RIPARIAN CORRIDOR
Cohoke Creek drains a watershed of 8.9 square miles above the King William Reservoir dam site (KWR-
IV). The entire Cohoke Creek watershed has an estimated drainage area of 17.0 square miles. Cohoke
Creek, a tributary to the Pamunkey River, flows in a southeasterly direction into Cohoke Millpond, which
is an existing impoundment downstream of the dam site. The upper end of Cohoke Millpond and the
Cohoke Millpond Dam itself are located approximately 2.1 river miles and 3.5 river miles, respectively,
downstream of the KWR-IV dam site.
The hydrologic system of the King William Reservoir drainage area consists of non-tidal, perennial and
intermittent streams. Flows from the reservoir drainage area are restricted by numerous beaver dams but
are otherwise unobstructed by manmade impoundments. However, immediately upstream of the dam
site, the main channel of Cohoke Creek passes through a triple 10 by 10-foot box culvert under State
Route 626; and the remains of the Valley Millpond Dam are just upstream of the Route 626 crossing.
Virginia Department of Transportation as-built plan and profile sheets for Route 626 (1959) show that the
top of this old earthen dam had an average elevation of 40 feet msl when the area was surveyed in 1957.
As stated in the FEIS (USCOE, 1997), it was assumed that all streams up to the normal pool elevation of
96 feet msl will be affected by the reservoir. Based on analysis of the King William and King and Queen
Courthouse U.S. Geological Survey (USGS) quadrangle maps (Scale 1 inch = 2,000 feet), a total of
approximately 21 river miles are located within the reservoir pool area, consisting of approximately 12
miles of intermittent and 9 miles of perennial streams.
7.2.7 FISHERIES
Anadromous fish utilization of the non-tidal portions of Cohoke Creek has been blocked by the existing
Cohoke Millpond Dam for well over a century by numerous beaver dams above Cohoke Millpond. An
impoundment of one sort or another has been in the vicinity of the Millpond dam for the last three
centuries. Investigators have concluded that even if fish passage were established at Cohoke Millpond, it
is very unlikely that anadromous clupeids would, given present stream habitat, exploit the section of
Cohoke Creek upstream of Route 626, the reservoir pool area (Garman, 1997a).
Construction of the King William Reservoir dam and inundation of the pool area are the project elements
with the greatest potential for impacts to fish species. Impacts associated with reservoir construction
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could include an increase in levels of suspended sediment, resulting in siltation that might affect fish in
the project area. These effects will be temporary and will be minimized by effective sediment control
measures.
Reservoir construction and impoundment will convert the creek system to a lacustrine system with deep-
water habitat and shallow shoreline areas. Some fish species present in the reservoir pool area may be
eliminated by the conversion to a lacustrine system; but most species currently found in Cohoke Creek
also have been documented in reservoir environments, as shown in Table 7-4.
7.2.8 UPLAND HABITAT
The King William Reservoir will impact approximately 1,089 acres of uplands. Some "net loss" of
uplands is unavoidable in a reservoir project; but the future habitat value of uplands inundated by the
reservoir would be uncertain without the project, because these uplands would be logged periodically (or
even clear cut) and might incur other long-term impacts such as agricultural or future residential
development. Many species inhabiting uplands in the pool area will be affected by reservoir inundation
and forced to migrate to other areas of similar habitat if the carrying capacity allows. If adjacent habitat is
at or near its carrying capacity for a particular species, such migrations could alter population dynamics.
Logging operations periodically force species inhabiting these areas to migrate to neighboring locations,
however, and that would continue in the absence of the reservoir project.
Less mobile species and species dependent on large contiguous upland tracts will be the most affected by
reservoir construction. Reptiles, amphibians, and some small mammals may be unable to migrate.
However, it is likely that suitable habitat for some of these animals will become established in the aquatic
fringe around the reservoir.
Reduction in habitat also could affect transient species. For example, many neotropical migratory
songbirds rely on large tracts of temperate forest for breeding. Because of continued forest fragmentation
and decreasing habitat from current timbering practices, these birds have become more susceptible to
predation. Continued reduction in forest habitat could result in decreased breeding success for certain
neotropical migratory bird species.
7.2.9 THREATENED AND ENDANGERED SPECIES
The USCOE has identified the bald eagle, sensitive joint-vetch, and small-whorled pogonia as species that
may be affected by the reservoir project. These species are federally listed as threatened and, therefore,
receive protection by the Endangered Species Act. The USFWS has determined, however, that the
reservoir project will not threaten the continued existence of any of these species or result in the
destruction or adverse modification of any critical habitat (USFWS, 1998).
There are four active bald eagle nests in the general vicinity of the project. One is located approximately
0.3 miles west of the Scotland Landing intake site (VDGIF, 1998) while the second is approximately %
mile downstream of the intake. Another is located approximately 1.9 miles downstream of the KWR-IV
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TABLE 7-4
Occurrence of Fish Species in Reservoir Environments
Cohoke Creek Non-tidal Waters Above Cohoke Millpond
".-" *"^; -^>, :j/;:--"spiMie?,i^^\^ป-;-.,ปซ!f >. -4>8H
Scientific Name:- ': ifc?t"H?^K- - , ~rซ> ~*^r ' ;
; Reservoir Environments ;'5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
18
v Rarely Inhabit
t Reservoir Environments
X
X
X
X
4
Sources:
Jenkins and Burkhead, 1993
VDGIF, 1993
R. Jenkins, personal communication, 1996
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dam site. The fourth nest is approximately 0.5 miles from the proposed pipeline to Diascund Reservoir in
New Kent County. No impact to eagle nesting sites is anticipated, because all project activities will occur
at distances greater than the recommended 1/4 mile protection zone around bald eagle nests (Therres et
al., 1993).
Surveys in the Mattaponi River by the Virginia Division of Natural Heritage and Rouse Environmental
Services (principal investigator Garrie Rouse) have recorded the presence of the sensitive joint-vetch at
Garnetts Creek Marsh, across the Mattaponi River from the intake site, and at a smaller marsh
approximately 600 feet upstream of Scotland Landing (VDCR, 1995; Rouse Environmental Services,
1996). Historical data show that the size of the population at Garnetts Creek fluctuates from year to year.
Impacts to the sensitive joint-vetch and approximately 2.5 acres of its potential habitat is unlikely during
construction and operation of the Mattaponi River intake. Impacts to the sensitive joint-vetch from wake
turbulence at the intake structure are expected to be negligible when compared to natural, high velocity,
freshwater floods. Pre- and post-construction monitoring will be conducted to evaluate sources of
potential erosion to this dynamic ecosystem with respect to operation of the intake.
A study conducted by Dr. David fiasco of Old Dominion University in 1996 concluded that the relative
changes in water velocities and sediment transport potential, if any, are so small that the possibility for
increased erosion on either side of the river, as a result of intake operation, is minimal. Sediment
deposition on the north side of the meander bend is expected to continue to increase the size of Garnetts
Creek Marsh, providing more possible future habitat for the sensitive joint-vetch.
The sensitive joint-vetch, which is generally thought to have a relatively narrow salinity tolerance, has
been recorded at several locations within a 15-mile reach of the Mattaponi River and a 19.5-mile reach of
the Pamunkey River. The wide geographic range of the sensitive joint-vetch along these rivers shows that
this species may be tolerant of oligohaline conditions and even mesohaline conditions on occasion.
Modeling of potential salinity changes in the Mattaponi River has shown that any salinity impacts of the
project will be minimal. Salinity will be monitored following project implementation.
Specimens of small-whorled pogonia were discovered at two locations at the King William Reservoir site.
During a 1993 field survey, one specimen was found in an approximately 60- to 70-year-old upland
deciduous forest, at the lower section of a southwest slope uphill from the confluence of two small
streams. In 1994, a colony of five individuals was found on an upland median in the floodplain of a
braided stream. Both small-whorled pogonia locations are in the pool area.
The individual plant was located again in 1994 and 1995, but not in 1996, 1997, or 1998. In 1997, the
forest surrounding the individual plant was clear cut and burned. The colony of five plants was located
again in 1995, but not in 1996, 1998; or 2002; but several individuals of the colony were observed in
1997.
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7.2.10 COHOKE CREEK DOWNSTREAM WETLANDS
There are approximately 186 acres of wetlands in the main stem of Cohoke Creek between the KWR-IV
dam site and the upper reaches of Cohoke Millpond. The hydrology of these wetlands ranges from
seasonally flooded to permanently flooded. These wetlands are supported hydrologically by flows
originating upstream of the King William Reservoir dam site.
As stipulated in the Virginia Department of Environmental Quality (VDEQ) Virginia Water Protection
(VWP) Permit, minimum King William Reservoir releases must equal the median monthly flows of
Cohoke Creek at Dam Site IV. The combination of increased local groundwater levels caused by
reservoir seepage, beaver dams, and the minimum reservoir release should be sufficient to maintain the
hydrology of the downstream wetlands. However, slight vegetation community changes could take place
downstream as a result of a relative shift in the hydrologic source from surface water to groundwater and
the attenuation of both flood and drought stream flows. Construction and operation of the reservoir will
not cause any dewatering of wetlands, and it is unlikely that the extent of the downstream wetlands will
be affected. Additional discussion of the project's potential for impacting downstream wetlands is
contained in Section 5 of this document.
7.3 PROJECT BENEFITS
In addition to the new water supply provided by the King William Reservoir, the project will provide
substantial benefits to not only the local community but the natural community as well.
7.3.1 REGIONAL APPROACH
It was recognized in the mid to late 1970s that the continuing growth projected for the Lower Peninsula of
Southeast Virginia would soon result in water demands that would exceed the capacity of existing water
supply sources (USCOE, 1984). Realizing that an additional raw water source for the Lower Peninsula
would likely originate from outside the Newport News Waterworks service area, in 1987 the City of
Newport News initiated an effort to enlist the participation of surrounding communities in a regional
approach to water supply planning.
Regional cooperation promotes more effective sharing and preservation of existing resources, reduces
competition for available supplies, and provides the economic benefits of large-scale projects. Most
importantly, combining the resources of several jurisdictions with a common need provides the
opportunity for considering many more water supply development alternatives which, in combination, can
result in the selection of a plan which has the greatest cumulative benefits and the least overall impacts
within the region.
7.3.2 WATER SUPPLY BENEFITS
The following is a list of water supply benefits that will be realized by completion of the King William
Reservoir project.
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The addition of King William Reservoir will nearly double the storage capacity of the current
system, providing storage needed to meet the long-term public water supply demands of the
Lower Peninsula.
King William Reservoir will increase the Lower Peninsula's current treated water safe yield by
more than one-third, providing the additional yield necessary to meet the increased long-term
public water supply demands of the Lower Peninsula.
The Lower Peninsula currently depends on the Chickahominy River and limited groundwater
wells for public water supply and storage in seven regional reservoirs. The King William
Reservoir will draw water from the Mattaponi River, providing a second river basin as a new
source of water. As a result, the Lower Peninsula will be less impacted from moderate droughts
due to the wider range of drainage area of two river basins. In addition, there will be greater
reliability in the event of droughts or water pollution events.
Construction of the King William Reservoir will provide localized direct and indirect seepage
from the reservoir to the Yorktown Aquifer, resulting in a net increase in aquifer recharge over
existing conditions.
7.3.3 HOST COMMUNITY BENEFITS
The following is a list of host community benefits that will be realized by completion of the King William
Reservoir project. j |
King William and New Kent Counties currently depend on groundwater as their water supply
source. Up to 3 mgd of surface water for King William County and 1 mgd for New Kent County
are reserved for their long-term water needs, providing a new and diversified source of supply.
New Kent County, through which part of the pipeline will run, will benefit from the development
of a new public recreational facility at the existing Diascund Creek Reservoir.
King William County will benefit from the development of a new public recreational facility at
King William Reservoir.
King William County will receive compensation from Newport News in the form of lease
payments and compensation for lost tax revenues.
Communities in the vicinity of the reservoir will gain the recreational benefits discussed in this
section, economic benefits from increased recreational activities (e.g., fishing, boating, and
hiking), and aesthetic enhancement with the increase in open water habitat.
The aforementioned aquifer recharge will benefit residents who use groundwater as their drinking
water supply.
King William Reservoir will displace no families. King William County is likely to benefit
during reservoir construction from increased employment and business activity.
The archaeological studies conducted in connection with the project provide a superb opportunity
to locate, identify, study and record archaeological finds or historic sites in the impoundment
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area, making a valuable contribution to our understanding of pre-contact Native American
civilization and culture, in particular (MAAR Associates, 1996) CFR.
7.3.4 PROJECT CONFIGURATION BENEFITS
The following is a list of benefits that will be realized by the configuration of the King William Reservoir
project.
The KWR-IV configuration avoids some of the impacts typically associated with reservoir
construction. The presence of Cohoke Millpond on Cohoke Creek has backed water up 1.4 miles
into the Creek for over a century. Anadromous fish are currently prevented from passing this
structure. In addition, Cohoke Millpond largely prevents the aquatic productivity of upstream
wetlands from being available to the downstream tidal Pamunkey River system. Since an
impoundment of one sort or another has been in this location for the last three centuries, the
KWR-IV configuration will not impact these functions. However, locating the reservoir almost
anywhere else would.
King William Reservoir is designed to operate as a flood-skimming project, with water being
withdrawn from the Mattaponi River only during periods when the flow is above prescribed
minimum instream -flow (MDF) levels. Therefore, project withdrawals should not affect the
availability of the resource for use by other water users.
Location of the intake in a tidal freshwater zone will preclude water level impacts to the
Mattaponi River.
The raw water intake is designed to have wedge-wire screens with very low entrance velocities
(<0.25 fps), and very small screen openings (1 millimeter slots) for the protection of anadromous
fish larvae. Location of the intake screens midway between the average water surface level and
the stream bottom will avoid any appreciable impingement or entrainment of fish eggs, because
the eggs of many resident and anadromous species either float on the surface or roll along the
bottom.
7.3.5 RECREATION BENEFITS
The following is a list of recreation benefits that will be realized by completion of the King William
Reservoir project.
King William County has negotiated the right to have five recreational swimming, fishing, and
boating (excluding the use of internal combustion engines). Other water-related activities, such
as canoeing and sailing,, would also be permitted.
Land adjacent to the reservoir can be used for picnic areas, camping sites, and nature trials.
New Kent County, through which part of the pipeline will run, will benefit from the development
of a new public recreational facility at the existing Diascund Creek Reservoir.
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7.3.6 FISHERIES BENEFITS
The following is a list of fisheries benefits that will be realized by completion of the King William
Reservoir project.
The reservoir will provide 1,526 acres of open water and aquatic shoreline habitat for freshwater
fish. Many of the species currently present in the drainage area are expected to populate the
reservoir. A fisheries management program in cooperation with the VDGIF will include
supplementary stocking of forage and game species to augment natural populations.
Establishment of a new recreational fishery with an expected economic benefit to King William
County.
Restoration of anadromous fish access to historic Mattaponi and Pamunkey River spawning areas
that are currently blocked to fish passage.
7.3.7 WILDLIFE BENEFITS
The following is a list of wildlife benefits that will be realized by completion of the King William
Reservoir project.
The open water created by the reservoir will add waterfowl habitat and forage area and may
increase the number of individuals and/or species of waterfowl that use the area.
The maintained pipeline right-of-way and other maintained areas will provide habitat edge for
wildlife species that utilize early successional habitats in their life cycle.
The open water habitat will provide easily accessible feeding habitat for the Bald Eagles that have
been identified in the area as well as for other shore birds and fish-eating birds.
Land preserved as part of the reservoir land acquisition plan and the mitigation plan will provide
permanent wildlife habitat that will not be developed.
7.3.8 LAND CONSERVATION BENEFITS
The following is a list of land conservation benefits that will be realized by completion of the King
William Reservoir project.
The project will preserve or restore approximately 3,500 acres of uplands in large tracts, and
create, restore, and preserve over 1,700 acres of wetlands. These areas will be protected in
perpetuity.
In accordance with the 1998 Land Acquisition Plan, nearly 1,900 acres will be protected as
buffer around the reservoir. Access to the reservoir will be controlled and uses will comply with
the Chesapeake Bay Preservation Act (CBPA) regulations. The remainder of the watershed will
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be designated as a "watershed protection area," which imposes restrictions on land clearing and
development.
7.3.9 NATURAL COMMUNITY BENEFITS
The RRWSG's Reservoir Mitigation Plan and this Fish and Wildlife Habitat Mitigation component
incorporate the following environmental enhancements that are above and beyond most mitigation criteria
for impacts incurred from construction of a reservoir. These elements of the overall mitigation "plan" are
detailed in this section.
Wetland Restoration/Creation: This plan will restore/create 806 acres of wetlands to achieve
2:1 compensation for impacts within the reservoir pool. Compensation at this rate will
restore/create 137 acres of wetlands over and above the requirements of the Norfolk District
Regulatory Branch's Wetland Mitigation Policy (USCOE). 2:1 compensation was volunteered by
the RRWSG to ensure that the project's wetland impacts will be more than offset by
compensatory mitigation projects, and to restore, to the extent practicable, natural functions of
habitats directly and indirectly impacted by the reservoir. Compensation for the habitat
conversion associated with the proposed pipeline is provided by the various wetland mitigation
elements.
Wetland Preservation: Approximately 300 acres of wetlands adjacent to the wetland mitigation
sites will be preserved in perpetuity. This will prevent any future logging, draining, or other
activity in these wetlands that could result in a conversion of the habitat from forested to scrub-
shrub or emergent communities. Preservation of wetlands adjacent to mitigation sites also will
ensure that the created/restored wetlands will be provided additional maximum protection, thus
increasing the likelihood of successful establishment of restored/created wetlands.
Shoreline Wetlands: Approximately 200 acres of vegetated wetlands would potentially develop
primarily between the 94 and 97-foot contours around the perimeter of the reservoir. This
wetland acreage also is above and beyond the 806-acre compensation plan.
Stream Restoration: A total of approximately 21 miles of small, first through third order
streams (9 miles of perennial and 12 miles of intermittent streams) will be displaced by the
reservoir. Streams will be restored and preserved at a 1:1 ratio for the miles impacted. Stream
restoration will involve such activities as livestock fencing, stabilizing stream banks, and
restoring stream bottoms to improve water quality and provide suitable habitat. This component
of the Reservoir Mitigation Plan will ensure that aquatic ecosystem impacts will be more than
offset by stream restoration projects.
Anadromous Fish Habitat Restoration: No impacts to anadromous fish movement are expected
to result from this project. However, the RRWSG has volunteered to work with the Virginia
Department of Game and Inland Fisheries (VDGIF) to identify one or more priority streams in
the York River Basin for restoration of anadromous fish passage. Streams targeted for fishways
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are those historically known to provide anadromous fish habitat. The RRWSG's proposals to
provide funding for improved fish passage are likely to enhance upstream passage of juvenile
American eels (elvers) at the locations where improvements are made. Decisions on the
appropriate type of passage facilities to construct and where they are to be constructed are the
responsibility of VDGIF, with the RRWSG only providing funding for those facilities. The
USFWS has agreed that anadromous fish passage funding can be credited as stream mitigation to
offset the impacts within the reservoir project area.
Upland Preservation and Restoration: Reservoir construction and filling will impact
approximately 1,089 acres of uplands. To mitigate for this loss of habitat, the RRWSG has made
an unprecedented proposal to restore, restrict, and/or preserve approximately 2,900 acres of
upland habitat. Of this, approximately 1,900 acres of upland forest will serve as a buffer for the
reservoir. The buffer consists of an area located adjacent to and extending at least 100 feet
(horizontal distance) landward of the reservoir pool area, which will be protected in perpetuity,
and an additional 100-foot extended area where no construction will be allowed. The buffer area
is extremely beneficial because it will shield large tracts of upland habitat from logging and
development and preserve this habitat for wildlife species dependent on large contiguous tracts of
land. In addition, many neotropical migratory songbirds rely on large tracts of temperate forest
for breeding. The upland restoration and preservation will help to counter an overall, long-term
trend toward greater forest fragmentation and reduction in forest habitat resulting from timbering
and urbanization, and therefore it is likely to benefit the long-term breeding success of these
species.
Wetland Education: The RRWSG has offered to provide financial assistance for a proposal by
the Pamunkey Indians to develop Tribal environmental regulations, to train and educate Tribal
members in the environmental sciences, particularly wetlands, to develop a database describing
specific wetland parameters associated with the existing tidal marsh on the Reservation, and to
provide access to the wetlands for Tribal members and Reservation visitors through the
construction of elevated walkways and trails.
7.4 MITIGATION PLAN GOALS AND ELEMENTS
The Mitigation Plan is the culmination of a cooperative effort to craft a series of interconnected
components that, when successfully implemented, will more than compensate for impacts associated with
the reservoir project. This endeavor has been jointly pursued by the RRWSG, USCOE, USEPA,
USFWS, and VDEQ. As described in the Final Environmental Impact Statement (USCOE, 1997), the
wetlands of Cohoke Creek are of high structural complexity and ecological value. Exact replication of
the wetland community is therefore unachievable. However, equivalent replacement with fully functional
wetlands is achievable. Successful implementation of the following plan elements will optimally mimic
the values and functions of the wetlands lost, and mitigate for other environmental impacts in the project
area.
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7.4.1 MITIGATION PLAN GOAL
The goal of the Mitigation Plan is to assure no net loss of wetland acreage and function, and to
compensate for other environmental impacts in the project area. This goal was developed in response to
regulatory policy and in coordination with state and federal regulatory agencies involved in the reservoir
project.
7.4.2 MITIGATION PLAN ELEMENTS
Wetland Compensation
Various wetland mitigation alternatives were selected to provide 2:1 compensation to offset the loss of
wetland acreage within the reservoir pool area and are described in Section 4. The wetland mitigation
plan includes over 806 acres of potential restoration and creation areas in the York and Rappahannock
River basins. The majority of the wetland mitigation areas are adjacent to existing streams and rivers.
Restoration of these riparian systems will provide in-kind compensation. Successful implementation of
the Plan will replace the wetland habitat and functions lost in the project area by a combination of
restoration of degraded wetlands (prior converted croplands) and wetland creation in selected locations.
Wetland Preservation
Many of the proposed wetland mitigation sites have adjacent wetland areas that would be purchased and
protected as buffers to the proposed restoration and creation areas. The final acreage of existing wetlands
preserved will depend on individual purchase agreements with landowners. However, it is expected that
approximately 300 acres of natural wetlands adjacent to the wetland mitigation areas will be preserved.
Although not counted in the 2:1 compensation ratio, these preservation areas adjoin the wetland
restoration and creation areas, serving to buffer the mitigation areas from disturbance and to provide a
seed source for dispersal into the mitigation sites. Preservation areas also provide a natural corridor for
many wildlife species to access the restored and created wetlands.
Reservoir
The King William Reservoir will provide 1,526 acres of open water habitat that will far exceed the loss of
existing open water within the project area. Shoreline wetlands and shallow water areas will also become
established. The reservoir and shoreline wetlands will provide spawning and nursery, nesting, migratory,
and wintering areas which will receive significant use by a variety of waterfowl, wading birds,
amphibians, and other aquatic and semi-aquatic organisms.
Stream Corridor Restoration
The plan will provide 1:1 compensation for the loss of 21 miles of low-order streams in the impoundment
area. Stream restoration and preservation will involve establishing corridors along stream systems,
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removing livestock access to streams, restoring stream banks, and eliminating erosional forces to
minimize sediment loads and scouring of stream banks and bottoms.
Fisheries
In addition to the improved fish habitat provided by stream corridor restoration, constructing a fish
passage structure in the York River basin will provide an expansion of anadromous fish spawning habitat.
Upland Restoration and Preservation f
Approximately 2,900 acres of upland habitat will be restored and/or preserved to mitigate for the impacts
within the project area. Of this, approximately 1,900 acres of upland forest will serve as a buffer for the
reservoir. Additional acreage will include approximately 700 acres of upland forests that will be restored
and/or preserved around the wetland mitigation sites. The final acreage will depend on purchase
negotiations with the individual landowners.
Endangered Species
Potential impacts to the three federally listed threatened species located in the vicinity of the King
William Reservoir project have been evaluated and mitigation strategies have been identified (i.e.,
monitoring, habitat preservation).
Cohoke Creek Downstream Wetland Corridor
Approximately 186 acres of wetlands and 620 acres of uplands will be preserved in the riparian corridor
of Cohoke Creek between the reservoir and the existing Cohoke Millpond. The wetland systems within
this corridor closely resemble those upstream in the project area. The corridor will enhance habitat
diversity and provide wildlife benefits to the existing downstream ecosystem. Under the terms of
agreement between the applicant and King William County, the host jurisdiction, King William County
has a right to build a future dam downstream of the currently proposed dam site (KWR-IV). Although
this right is preserved in the host agreement, the RRWSG is unaware of any plans to develop a
downstream impoundment on Cohoke Creek. If the County ever desires to build another impoundment in
Cohoke Creek downstream of Dam Site IV, they would be subject to the same public interest review
process and regulatory approvals that the RRWSG has faced.
Pipeline
The wetland compensation elements of the wetland mitigation plan more than offset the wetland cover
type conversion associated with the proposed pipeline route.
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Wetland Education
The RRWSG has offered to assist the Pamunkey and Mattaponi Indian Tribes to develop educational
programs for promoting and preserving natural resources on their Reservations.
Best Management Practices
Best management practices and erosion and sediment control techniques will be implemented to avoid or
minimize environmental impacts associated with construction of the project.
7.5 WETLAND RESTORATION/CREATION
The RRWSG's Reservoir Mitigation Plan includes over 806 acres of wetland restoration and creation to
provide 2:1 compensation for wetland acreage losses. By mitigating for wetland impacts at a ratio of 2:1
(impacts to compensation), the RRWSG's wetland mitigation proposal exceeds the requirements of the
Norfolk District USCOE's mitigation policy by 137 acres or 20 percent. Wetland mitigation is presented
in detail in Section 4 of this document.
The wetland mitigation plan has been developed in cooperation with state and federal agencies involved
in the project. A Mitigation Team was assembled to provide guidance for mitigation site selection and
evaluation. Agency team members include representatives from the USCOE, USEPA, USFWS, and
VDEQ.
The plan includes 10 sites in the York Basin and 1 in the Rappahannock Basin. The Plan also describes
several contingency sites that might be used for mitigation, if any of the primary sites have to be
eliminated or reduced in size in final design or implementation.
7.5.1 WETLAND RESTORATION/CREATION
After considerable evaluation and site review with the federal and state agencies, 10 mitigation sites were
selected in the York River watershed and 1 in the Rappahannock River drainage, as shown on Figure 7-1.
These areas can provide at least 806 acres of wetland restoration/creation.
Wetland restoration means returning to a formerly existing wetland character and function at locations
where today wetlands do not exist, or where they exist in a degraded condition. Wetland creation is
defined as the construction of wetlands on sites that exhibit no historical wetland characteristics.
The majority of the wetland mitigation areas are adjacent to existing streams and rivers. Restoration of
degraded wetlands and creation of new wetlands will enhance these riparian systems and provide in-kind
compensation for some of the wetland functions and habitat losses associated with the project.
Approximately 300 acres of natural wetlands adjacent to the wetland mitigation areas have been identified
for preservation. These preserved wetlands will serve to buffer the mitigation areas from disturbance and
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provide a seed source for dispersal into the mitigation sites. Protection of these natural systems will
ensure their continued existence. Upland preservation and restoration areas are incorporated into the plan
to serve as a buffer for the wetland system and to provide habitat for species that utilize the
upland/wetland ecosystem.
Site information and conceptual design plans are presented in Section 4 of this Plan. Final design plans
will be developed for each site prior to implementation, and will be coordinated, as required, with state
and federal agencies. Site-specific monitoring plans and performance criteria for the wetland
compensation sites will be developed during the final design phase. The wetland mitigation-monitoring
plan will be used to evaluate whether the implemented site plans are establishing self-sustaining and
functional wetlands.
7.5.2 CONTINGENCY SITES
The Wetland Mitigation Plan also describes another 290 acres of possible wetland mitigation (36 percent
of the 806 acres of primary sites) as "contingency acreage". Contingency sites would be utilized if
development of one or more primary sites were determined to be infeasible during pre-design monitoring,
if the acreage of the primary sites is reduced in final design, or if post-construction monitoring indicates
that a mitigation site is not achieving its establishment criteria.
7.5.3 PRESERVATION AGREEMENTS
The long-term success of these mitigation activities will rely heavily on the elements of protection and
preservation. Land use will be limited by restrictive covenants and/or conservation easements that will
serve to preserve the land in perpetuity.
7.5.4 SUMMARY
Over 806 acres of wetland restoration/creation areas have been identified in the York and Rappahannock
River basins. Any deficiency in mitigation acreage will be satisfied by development of contingency sites.
7.6 RESERVOIR
The King William Reservoir will provide 1,526 acres of open water and shoreline habitat, more than
compensating for the impacts to 34 acres of open water inundated in the pool area. Of that, 1,526 acres,
approximately 1,251 acres of new open water with depths greater than 6 feet will be created and will
provide valuable habitat for freshwater fish, invertebrates, and migratory waterfowl. The reservoir will
have a maximum depth of 68 feet, a mean depth of 25 feet, and a total water volume of approximately
12.2 billion gallons.
Approximately 322 acres of shoreline wetlands and shallow water areas are expected to develop between
the 90 and 97-foot contours of the 77-mile reservoir shoreline. These wetlands and shallow water areas
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are valuable to fish and wildlife species that utilize shoreline habitat. The reservoir will also provide
substantial recreational opportunities in King William County.
7.6.1 RESERVOIR FUNCTIONS
Conversion of existing wetland habitat in the pool area to a lacustrine system will provide several new
functions while maintaining many existing functions. The project will provide detention storage and
hydrologic management during storm events to prevent sediment loads and erosion of downstream areas.
These flood retention and storage functions may be analogous to flood detention functions performed by
the existing wetlands in the pool area (AWWA, 1994). A detailed description of this reservoir flood flow
alteration function is provided in the Main Report (Volume II) of the Final Environmental Impact
Statement (USCOE, 1997).
7.6.2 LACUSTRINE HABITAT
Reservoir construction and filling will result in a conversion of habitat from upland forests and wetlands
to an aquatic open water system. The existing wildlife species composition will change to a community
that benefits from the reservoir and shoreline area. The reservoir will provide spawning and nursery,
nesting, migratory, and wintering areas which will receive significant use by a variety of waterfowl,
wading birds, amphibians, and other aquatic organisms. As requested by the USFWS, standing timber
will be left in the reservoir between the 90 and 96 foot contours to provide habitat benefits for some fish
and wildlife. Table 7-5 identifies fish and wildlife species expected to use the lacustrine habitat provided
by the King William Reservoir.
The reservoir will convert riverine habitat in the pool area to a lacustrine system, which may eliminate
some fish species due to changes in habitat. However, according to Jenkins and Burkhead (1993) and
Virginia Department of Game and Inland Fisheries (VDGIF) surveys of existing reservoirs, 19 of the 23
species found in Cohoke Creek above Cohoke Millpond also inhabit reservoirs. A fisheries management
program will also be implemented that includes supplementary stocking of forage and game species to
augment the natural populations, and VDGIF has indicated preliminarily that the reservoir appears
suitable for stocking efforts to establish a striped bass fishery (VDGIF, personal communication, 1993).
The project will provide riparian habitat in the buffer around the reservoir and habitat for wetland
dependent species along the margins of the reservoir. Also, as the reservoir traps sediment and nutrients,
elevations suitable for establishment of new littoral wetlands may increase.
The habitat benefits of the reservoir may be especially significant for the Bald Eagle, which is federally
designated as "threatened" under the Endangered Species Act. The reservoir will provide extensive open
water foraging habitat, surrounded by 77 miles of shoreline with large diameter trees suitable for eagle
nesting, roosting, and perching sites. As described above, the reservoir will support a variety of
freshwater fish species. This combination of open water, shoreline forest, and fish species will provide
excellent foraging habitat for bald eagles in the vicinity and may well provide essential habitat for
additional nesting pairs. Bald eagle foraging and nesting habitat has been successfully created at other
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TABLE 7-5
Typical Fish And Wildlife of the
Lacustrine Community
Scientific Name
Amphibians
Hyla crucifer
Notophthalmus viridescens
Rana catesbeiana
Rana clamitans
Rana sphenocephala
Common Name
Spring Peeper
Red-Spotted Newt
Bullfrog
Green Frog
Southern Leopard Frog
Reptiles
Chelydra serpent ina
Chrysemys picta
Clemmys guttata
Kinosternon subrubrwn
Nerodia sipedon
Sternotherus odoratus
Snapping Turtle
Painted Turtle
Spotted Turtle
fetern Mud Turtle
Northern Water Snake
fetern Musk Turtle
Birds
Aix sponsa
Anas platyrhyncnos
Ardea herodias
Branta canadensis
Bucephala albeola
Casmerodius albus
Circus cyaneus
Haliaeetus leucocephalus
Lophodytes cucullatus
Pandion haliaetus
Phalacrocorax auritus
Wood Duck
Mallard
Great Blue Heron
Canada Goose
Bufflehead
Great gret
Northern Harrier
Bald ^le
Hooded Merganser
Osprey
Double-crested Cormorant
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TABLE 7-5 (cont'd)
Typical Fish And Wildlife of the
Lacustrine Community
Scientific Name
Common Name
Fish
Ictalurus natalis
Ictalurus nebulosus
Amia calva
Aphredoderus sayanus
Centrarchus macropterus
Cyprinus carpio
Enneacanthus gloriosus
Erimyzon sucetta
Esox americanus
Esox niger
Esox lucius
Fundulus diaphanus
Gambusia affinis
Lepisosteus osseus
Lepomis gibbosus
Ictalurus punctatus
Micropterus salmoides
Morons americana
Moxostoma macrolepidotum
Notemigonus crysoleucas
Noturus gyrinus
Perca flavescens
Pomoxis annularis
Yellow Bullhead
Brown Bullhead
Bowfm
Pirate Perch
Flier
Common Carp
Bluespotted Sunfish
Lake Chubsucker
Redfin Pickerel
Chain Pickerel
Northern Pike
Banded Killifish
Sstern Mosquitofish
Longnose Gar
Pumpkinseed
Channel Catfish
Largemouth Bass
White Perch
Shorthead Redhorse
Golden Shiner
Tadpole Madtom
Yellow Perch
White Crappie
Mammals
Castor canadensis
Lutra canadensis
Ondatra zibethicus
Beasr
Rier Otter
Muskrat
Sources: Martof et al., 1980;Ferrand, 1988;Webs ter et al., 1985;4nkins andBurkhead, 1993.
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reservoirs in the region and, with appropriate management efforts, similar success could be achieved at
the King William Reservoir site, especially given the following factors:
Extensive undeveloped shoreline with large diameter trees will exist around the reservoir. This
shoreline and adjacent areas will greatly expand local bald eagle habitat by providing nesting,
roosting, and perching sites.
Extensive shallow water areas and a healthy freshwater fishery will exist in the reservoir, thus
greatly expanding the bald eagles' local foraging habitat and potential food supply.
Large numbers of active bald eagle nesting sites already exist in the York River Watershed,
including a nest located on Cohoke Creek 1.9 miles downstream of the KWR-IV dam site.
Additional habitat provided by the reservoir may support an expanded eagle population in the
York River Watershed.
King William Reservoir will provide an environment more suited to bald eagle establishment
than exists under current land use conditions, which include timbering and hunting.
7.6.3 SHORELINE HABITAT
Approximately 322 acres of vegetated wetlands and shallow water habitat would potentially develop
around the 77-mile reservoir shoreline between the 90 and 97-foot contours. The King William Reservoir
- Reservoir Fringe Study (Malcolm Pirnie, 1997a) provides a qualitative assessment of expected shoreline
wetland establishment based on a review of land development and habitat conditions at five existing
regional reference reservoirs (Diascund, Little Creek, Lee Hall, Beaver Dam, and Waller Mill) in the
Virginia Peninsula region between the York and James Rivers. Photographs of shoreline wetlands that
have developed in these reservoirs are included in Figures 7-2 through 7-6.
The methods used in the Reservoir Fringe Study were similar to those used by Jenson, et al. (1992) in
developing a predictive model for vegetation distribution at a Department of Energy lake in South
Carolina. Development conditions were established from surrounding land use patterns and factors
influencing local growth. Shoreline wetland habitat conditions were developed from factors such as
depth of water, slope, aspect, soil, fetch and shading. Based upon those conditions assessed as favorable
to the establishment of shoreline wetlands, it was estimated that 121 acres of vegetated shoreline
emergent wetlands and more than 80 acres of submerged, vegetated wetlands will become established
sustainable communities in the littoral zone surrounding the King William Reservoir.
As seen in the five reference reservoirs, the amount and composition of vegetated wetlands is variable
both at the shoreline and in the shallows. Some reservoirs show extensive emergent and scrub-shrub
vegetation in the shallows, while others are more dominated by submerged aquatic vegetation in the
shallows and woody wetland vegetation at the shoreline. Development of vegetated wetlands is
dependent on the physical characteristics of the reservoir including water depth (elevation), shoreline
slope, fetch, inlet width, soil, fluctuating water level, reservoir age and shoreline development.
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Approximately 200 acres of vegetated wetlands are expected to potentially develop around the margins of
the new King William Reservoir, primarily between the 94 and 97-foot contours. This wetland acreage is
above and beyond the 2:1 wetlands compensation plan. In general, wetland composition will vary with
water depth and age of the reservoir. Emergent wetlands will develop first, within 5 years after the
reservoir is completed and filled. As the reservoir ages, scrub-shrub vegetation will come to dominate the
shoreline while emergent and submerged aquatic vegetation continues to flourish in shallow water areas
that are sunny, flat, and up to 2 feet deep. Land development around the reservoir will be minimal and
should have no effect on wetland establishment.
7.6.3.1 Comparable Shoreline Wetland Systems
Shoreline wetlands have become established at numerous water supply reservoirs throughout the United
States, as in the five existing reference reservoirs in the York-James Peninsula. Table 7-6, adapted from
Expediting Water Projects: Benefits Assessment and Wetland Mitigation Banking (AWWA, 1994), lists
19 water supply reservoirs possessing littoral zone shoreline wetland vegetation. The climate and mean
depth of those 19 reservoirs were reviewed to derive a list of reservoirs comparable to the proposed King
William Reservoir. Reservoirs in arid regions west of the Mississippi River, where annual evaporation
often greatly exceeds annual precipitation, were excluded as unrepresentative of conditions of the King
William Reservoir. Three of the remaining reservoirs, Occoquan Reservoir, Dog Lake, and Lake
Monroe, which have mean depths within 10 feet of the mean depth of the King William Reservoir (24.7
feet), were selected for comparison. The vegetated littoral zones associated with these reservoirs
represent between 6 and 22 percent of the respective reservoir areas. The 200-acre shoreline wetland
estimate for the King William Reservoir (elevation 90 to 97 msl) is approximately 13 percent of the total
reservoir area, 1,526 acres. The shoreline wetland acreage along the perimeter of the King William
Reservoir is, therefore, consistent with experience at other reservoirs possessing similar climatic and
depth characteristics.
7.6.3.2 Shoreline Wetlands under Section 404
The 1990 Memorandum of Agreement (MOA) between the USEPA and the Department of the Army
concerning the Determination of Mitigation under the Clean Water Act Section 404(b)(l) Guidelines
(USEPA and USCOE, 1990) states that compensatory actions (e.g., restoration of existing degraded
wetlands or creation of man-made wetlands) should be undertaken, when practicable, in areas adjacent or
contiguous to the discharge site (on-site compensatory mitigation). To meet these requirements, shoreline
wetland areas have been included as practicable compensatory mitigation sites in several recently
permitted reservoir projects. The following list of permittees received USCOE permits where wetland
impacts were partially or entirely offset by shoreline wetland systems.
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TABLE 7-6
Littoral Zone Area of Representative Reservoirs
Reservoir
Quabbin, MA
Occoquan, VA
Cherokee, TN
Cumberland, KY
Dog Lake, GA
Taylor, FL
Springfield, IL
Monroe, IN
Morris, AR
Texoma, TX
Hefner, OK
Red Rock, IA
Turtle Creek, KA
Standley, CO
Bighorn, MN
Strawberry, UT
Mead, NV
Pardee, CA
Barney, OR
Mean Depth (ft)
44.9
18.4
49.9
95.8
14.8
6.6
12.5
17.4
54.1
29.8
29.1
7.2
26.9
36.1
78.7
49.2
180.4
91.8
20.0
I * Reservoir
Area (Acres)
23,559
1,841
30,009
63,549
252
4,001
4,302
10,749
34,210
87,996
2,580
8,953
15,790
1,221
17,965
8,402
163,330
2,259
220
Vegetated Littoral
Zone (Acres)
1,357
116
1,557
2,496
30
2,501
287
2,360
1,490
11,323
230
1,782
173
99
717
99
2,184
91
77
Vegetated Littoral Zone
(% of reservoir area)
5
6
5
4
12
38
6
22
4
11
8
17
1
7
4
1
1
4
26
Source: AWWA, 1994
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Permittee
Cabarrus County,
North Carolina
Prince Edward County,
Virginia
Little Kanawha Soil
Conservation District
Gloucester County,
Virginia
Stafford County,
Virginia
Reservoir
Coddle Creek
Reservoir
Sandy River
Reservoir
North Fork Hughes
River Reservoir in
Ritchie County, WV
Beaverdam Swamp
Reservoir
South Reservoir
Expansion
Quantity of
Shoreline Wetlands
186 acres
50.6 acres
25 acres
N/A
3 acres
Comments
Shoreline wetlands
represent entire wetland
creation effort.
Combined shoreline and
borrow area wetlands for
entire compensatory
mitigation acreage.
Shoreline wetlands
represent 90 percent of
wetland creation effort.
Shoreline wetland area
not defined, but
represents an important
component of
compensatory
mitigation.
Shoreline wetlands
represent 27 percent of
the mitigation effort.
More than 200 acres of shoreline wetlands are expected to develop on-site around the King William
Reservoir. The USCOE has determined, however, that these new wetlands will not be credited against
RRWSG's 2:1 compensation goal. The Reservoir Fringe Study and other analyses nevertheless
demonstrate that the margins of the reservoir may support a variety of wetland habitats, which should be
recognized as a significant environmental benefit of the reservoir project.
7.6.3.3 Shoreline Wetlands and Reservoir Operations
As demonstrated below, shoreline wetland development will be compatible with reservoir operations.
Water level fluctuations following construction will be conducive to shoreline wetland proliferation, and
shoreline wetland locations will be protected from shoreline erosion.
Water Level Fluctuation
Shoreline wetland systems depend on fluctuating hydroperiods for nourishment. Nutrients are added to
the wetland systems during periods of higher water elevations, and detritus and waste products are
removed as water levels recede. Mitsch and Gosselink (1993) state that pulse-fed wetlands are often the
most productive wetlands and are the most favorable for exporting materials, energy, and biota to
adjacent ecosystems. When these fluctuations become extreme in frequency and duration, however,
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especially in reservoirs possessing pronounced shoreline slopes, shoreline wetland development may be
inhibited.
King William Reservoir operating rules mandated by the State Water Control Board's 401
Certification/Virginia Water Protection Permit (VWPP) require Newport News Waterworks to rely
primarily on its existing surface water sources, in the James River Basin (i.e., Chickahominy River
withdrawals), in preference to Mattaponi River withdrawals and the new King William Reservoir. Also,
in the early years of the project the new reservoir storage will be needed and used mostly to assure the
adequacy of regional public water supplies during moderate to severe droughts, which means that storage
drawdowns will be limited and infrequent. (Existing sources should be adequate to meet expected
demands under normal conditions for some years to come, but it is projected that the reservoir will be
needed to avoid a public water supply "safe yield" deficit under drought conditions by the year 2010.)
Aside from system startup, testing, and periodic operation and maintenance, little or no water will be
pumped from the reservoir in its early years, except during droughts. Based on operational requirements
and demand projections, King William Reservoir is expected to remain within 1 foot of its normal pool
elevation more than 80 percent of the time during its first 30 years. Reservoir drawdowns are anticipated
primarily during the summer months, which coincides with the lower water levels naturally associated
with wetland plant growing seasons. These conditions should be highly favorable to the establishment of
vegetation, stabilization of shorelines, and development of healthy and durable wetland communities.
Newport News Waterworks' Diascund and Little Creek Reservoirs have slope gradients that are
comparable to the King William Reservoir, but both of these existing reservoirs experience greater water
level fluctuations than those projected for the King William Reservoir. Diascund Reservoir was
established in 1963 and Little Creek in 1981. Drawdown records for those reservoirs were not readily
available for periods before 1991, however, so data for the most recent 6 1/2 years (i.e., January 1991 to
June 1997) were used for comparison. During that period of record, Little Creek Reservoir remained
within 1 foot of its normal pool elevation 60 percent of the time, and Diascund only 51 percent of the
time. Both Diascund and Little Creek Reservoirs maintain viable shoreline wetland communities under
those conditions. It is reasonable to assume that similar but smaller water level fluctuations likewise will
not inhibit wetland development along the King William Reservoir shoreline.
Even in the early years of the new reservoir, measurable storage drawdowns may occur under drought
conditions, when the need to pump stored water from King William Reservoir to replace shortfalls in
existing supplies coincides with diminished freshwater discharges in the Mattaponi River. The 401
Certification/VWPP prohibits water withdrawals that would reduce net downstream flows in the
Mattaponi River below specified minimum instream flow (MIF) levels, to protect the aquatic environment
and instream beneficial uses. During droughts, river withdrawals will be limited or precluded by these
MIF conditions at the same time that water stored in the reservoir is being used to replace shortages
elsewhere in the system, causing reservoir drawdowns. As a result, some drying may be experienced in
the reservoir shoreline zone. These effects will be temporary, however, and they will mimic the effects of
periodic droughts on existing, natural wetland systems.
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Bank Stabilization
Shoreline erosion is detrimental to vegetation establishment. It can be caused by a variety of factors
including wind-generated waves, groundwater seepage, water level fluctuations, runoff from adjacent
uplands, and waterfront development. Sites expected to establish shoreline wetlands along the reservoir
perimeter possess favorable slope, soils, fetch, and water depth. In addition, standing timber will
dissipate erosional impacts on the shoreline wetland areas. Timber will not be cleared above 90 feet msl,
thereby minimizing wind and wave action. The vast majority of the shoreline will be protected from
human disturbance. Except for a few minor areas, an upland buffer will extend at least 100 feet from the
reservoir, preserving in perpetuity upland habitat adjacent to the open water and shoreline wetlands of the
reservoir.
Based on the success of shoreline wetland establishment in other reservoir projects and predictive
modeling used for this evaluation, it is expected that approximately 200 acres of shoreline wetlands will
become established around the King William Reservoir.
7.6.4 RECREATIONAL OPPORTUNITIES
Most large public water supply reservoirs provide significant recreational benefits, and King William
Reservoir will be no exception. There are no water supply reservoirs in King William County now, but
there are significant and growing recreational uses of the Mattaponi and Pamunkey Rivers, which form
the County's borders with King and Queen County and New Kent County respectively. King William
Reservoir is likely to be a popular recreational venue, and its availability as an alternative may reduce to
some extent the increasing recreational pressures on the two rivers.
The RRWSG's host community agreement with King William County provides for the establishment of
recreational areas around the reservoir, and recreational activities that do not threaten to introduce
pollutants into the reservoir will be encouraged. Recreational facilities will include pavilions, picnic
tables and grilles, and designated areas for hiking and sightseeing. Areas of undisturbed land around
recreational facilities will protect the aquatic fringe from human disturbance.
Fishing piers, boat ramps, and floating boat docks will be constructed to provide public access to the
reservoir. Gasoline powered boats will be prohibited, to avoid contamination of public water supplies
with petroleum distillates. The Virginia Department of Game and Inland Fisheries will stock the reservoir
with game fish. Fishing may be allowed year-round.
7.7 STREAM CORRIDOR RESTORATION/PRESERVATION
Stream corridor restoration and preservation is included in the Reservoir Mitigation Plan to offset the
losses associated with the flooding of riparian habitat in the reservoir pool area. Based on analysis of the
King William and King and Queen Courthouse U.S. Geological Survey (USGS) quadrangle maps (Scale
1 inch = 2,000 feet), a total of approximately 21 miles of small, first through third-order streams,
consisting of 9 miles of perennial and 12 miles of intermittent streams, will be displaced. Streams will be
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restored and preserved at a 1:1 ratio for the miles impacted in Cohoke Creek. The stream
restoration/preservation component of the plan is presented in conceptual detail in Section 6 of this
Mitigation Plan.
Restoration of impacted streams will be accomplished by various mechanisms that may include fencing to
prevent livestock from grazing along stream banks and entering streams, preservation, or other land use
restrictions. Riparian vegetation will be encouraged to reestablish, providing a mechanism for sediment
and nutrient removal from runoff and more favorable water temperatures. These actions could yield
water quality improvements that would foster the growth of rooted aquatic vegetation and enhance habitat
quality for fish and invertebrates. Establishing lengthy, streamside forested corridors will also provide
riparian habitat for wildlife species. In time, the quality of this restored habitat may approach the value of
the area's existing riparian forests.
Conservation agreements to preserve the vegetated buffers established in the stream corridors will be
pursued with landowners.
7.8 FISHERIES
The King William Reservoir project design includes numerous recommended strategies to avoid and
minimize potential impacts to commercial and recreational fisheries. The Mitigation Plan also includes a
fish passage as possible compensation for potential impacts to anadromous fish habitat.
7.8.1 RAW WATER INTAKE ON THE MATTAPONI RIVER
The RRWSG has followed recommendations of the U.S. Department of Commerce - Marine Fisheries
Service regarding the placement of screens on the raw water intake structure to minimize impacts to
anadromous fish eggs and larvae. To meet this requirement, design elements on the cutting edge of
technology were incorporated to include wedge-wire screen with very low entrance velocities (<0.25 fps),
and very small screen openings (1 millimeter slots). The screens will be placed midway between the river
bottom and average water surface. These state of the art protection elements are more stringent than any
known federal or state requirements. As a result of these precautionary measures, appreciable
impingement or entrainment impacts are unlikely. However, a comprehensive monitoring plan is
currently being developed that will include pre-operational ichthyoplankton monitoring as well as
entrainment ichthyoplankton monitoring.
Dr. Greg Garman of Virginia Commonwealth University, a recognized authority on anadromous fisheries
whose selection for this effort was endorsed by federal agencies including the USFWS, evaluated
potential impacts of the water withdrawals on anadromous fisheries in the Mattaponi River. According to
Dr. Carman's evaluation, impacts to anadromous fish should be minimal (Garman, 1997a). He also
concluded that anadromous fish should not be measurably affected by any potential changes in Mattaponi
River salinity conditions caused by river withdrawals.
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The Virginia Institute of Marine Science (VIMS) conducted a modeling analysis on potential salinity
changes in the Mattaponi River resulting from the withdrawals. As indicated in VIMS' report (Appendix
J of the Final Environmental Impact Statement) (Corps, 1997a), only slight differences in simulated
historical and withdrawal salinity records for Mattaponi River transects were observed in the salinity
model output, and natural salinity fluctuations greatly exceed the minuscule changes that will result from
the water withdrawals.
7.8.2 RESERVOIR POOL AREA
As previously mentioned, even if fish passage were possible at Cohoke Millpond Dam, it is very unlikely
that anadromous fish would utilize the upstream area of the Cohoke Creek system for spawning (Garman,
1997b). This conclusion is based on the presence of extensive beaver dams and the very limited amount
of appropriate habitat throughout this section of the Creek.
A significant freshwater fishery will be created by the reservoir that will more than compensate for the
project's impacts to resident fisheries. Most of the species currently inhabiting the project area have been
documented in reservoir environments. A fisheries stocking and management plan will be developed in
coordination with VDGIF to establish game fish populations. Construction of boat launching facilities,
fishing piers, and floating boat docks will provide public access to the reservoir for recreational fishing.
The fishing piers will be accessible to handicapped persons.
7.8.3 FISH PASSAGE
The RRWSG is working with the Virginia Department of Game and Inland Fisheries (VDGIF) to identify
one or more priority streams in the York River Basin for fish passage restoration. Streams targeted for
fishways are historically known to provide anadromous fish habitat. Several dams are currently being
evaluated for retrofit.
7.8.4 FISH HATCHERY IMPROVEMENTS
To increase the stock of anadromous fish in the greater York River watershed, the Pamunkey and
Mattaponi Indian Tribes desire to upgrade their fish hatcheries on the Pamunkey and Mattaponi Rivers,
respectively. The RRWSG is engaged in consultations under Section 106 of the National Historic
Preservation Act with the Corps, the State Historic Preservation Office, the Advisory Council on Historic
Preservation, and three local Tribes. This consultation may include possible financial support for such
projects to mitigate for potential impacts to Tribal cultural resources.
7.9 OTHER ENVIRONMENTAL ELEMENTS
7.9.1 UPLAND RESTORATION AND PRESERVATION
Approximately 2,900 acres of upland habitat will be restored, restricted and/or preserved as part of the
Mitigation Plan. This includes 1,900 acres of upland forest that will serve as a buffer around the
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reservoir. The buffer consists of a 100-foot preservation setback (1,300 acres) from the reservoir pool area
that will be protected in perpetuity and an additional 100-foot construction setback (600 acres) in which
development will be strictly limited. The buffer area will preserve a large tract of contiguous upland
habitat around the reservoir. In addition, approximately 700 acres will be restored and/or preserved
around the wetland mitigation sites.
Mature, mast-producing hardwood areas are typically defined as older upland forests composed mainly of
beech, hickory, and oak trees. Most of the buffer area currently is managed for timber harvest. Since the
current trend in the timber industry is to promote growth of hardwood trees due to their high value, those
areas having stands over 30 years of age are being targeted for logging. Forestry has long been a
significant part of King William County's economy, and a continuing demand for forest products is
assured by the presence of major wood, pulp and paper processing and manufacturing facilities in the
County and nearby. Therefore, the majority of the mature, mast-producing hardwoods and other mixed
deciduous stands in these areas of the buffer would be logged if left to current practices. The 1,300-acre
preservation buffer will preserve mature hardwood stands, and it will be managed to allow natural
succession of the remainder of the area to mature hardwood forests and mixed deciduous/evergreen
forests.
Continued forest fragmentation from current timbering practices has resulted in the decline of many
species. The upland restoration/preservation areas will be managed for natural succession into mature
hardwood forests, providing large areas of habitat for species that require contiguous hardwood forests.
The buffer also will provide forest edge habitat and riparian edge habitat. Therefore, these areas may
support several species that are currently using the habitat within the proposed reservoir pool area.
The upland buffer areas adjacent to the wetland mitigation sites also will be preserved in perpetuity, along
with the wetland mitigation areas, and allowed to mature into mixed deciduous forests and mast-
producing hardwood stands. The areas will also provide forest edge habitat for species that may use the
wetland complexes or adjacent farm fields. Most of the mitigation sites are located adjacent to existing
forested areas; therefore, restoration of adjacent forested areas will reestablish large contiguous tracts of
upland forest. Due to continued human incursion into these areas, restoration and preservation of large
upland tracts is of particular value to species dependent on this community type. These large
wetland/upland complexes will help to offset habitat fragmentation elsewhere in the area, by creating
expanded forest corridors along the Mattaponi and Pamunkey Rivers. The exacl acreage of upland
preservation and restoration around the mitigation sites is not currently known at this time. However, it is
anticipated that approximately 700 acres will be preserved depending on purchase arrangements with
individual landowners.
Due to continued logging pressure in the proposed reservoir pool area, the upland buffer areas around the
reservoir and the mitigation sites, upon reaching maturation, will surpass the quality of habitat that
otherwise would be provided by the upland areas impacted by the reservoir. A majority of the mitigation
sites containing these restored and/or preserved upland/wetland complexes are located adjacent to the
Pamunkey or Mattaponi Rivers or their tributaries. Therefore, these upland complexes may also provide
habitat for species that use these large rivers for feeding, breeding, or roosting.
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7.9.2 ENDANGERED SPECIES
Three federally listed threatened species are found in the vicinity of the King William Reservoir project:
the bald eagle, sensitive joint-vetch, and small-whorled pogonia.
No impacts to eagles or their nesting sites is anticipated, because all project activities will occur at
distances greater than the recommended 1/4 mile protection zone around bald eagle nests (Therres et al.,
1993). After construction, the reservoir will provide open water habitat for bald eagles. If new bald eagle
nests are constructed within 1/4 mile of the project area or mitigation sites before or during project
construction, the Corps and USFWS will be contacted before any further action is taken, to ensure
compliance with the Endangered Species Act.
As previously discussed, sensitive joint-vetch has been recorded across the Mattaponi River from the
intake site, at Garnetts Creek Marsh and at a smaller marsh located approximately 600 feet upstream of
Scotland Landing; but investigations of potential impacts to sensitive joint-vetch from construction or
operation of the new raw water intake at Scotland Landing have indicated that any such impacts will be
negligible. However, the following steps will be taken to further minimize the potential for adverse
effects:
Locating work staging areas away from wetland areas.
Implementing sediment control measures at all times.
Avoiding compaction and disturbance of wetland soils.
An ecological monitoring plan will be developed for the Mattaponi River, to evaluate whether
withdrawals by the RRWSG are having any significant effect on the River's ecology. The monitoring
plan also will be designed to identify any effects on the downstream colonies of sensitive joint-vetch,
which may experience minor variations from natural salinity conditions. Development and
implementation of this monitoring plan is expected to be a condition of a Corps Section 404 permit for
the King William Reservoir project. If it is determined that impacts to the sensitive joint-vetch result
from the water withdrawal or intake structure, the Corps and USFWS will be consulted to determine
appropriate strategies for remedying the impact.
Known populations and suitable habitat for the small-whorled pogonia, which are under threat of
development, were identified as candidate sites for preservation by Dr. Donna Ware of the College of
William and Mary (D. M. E. Ware, personal communication, 1997). These sites include White Marsh
Colony, Gloucester County; the Casey Property/Ford's Colony Site, James City County; and remnants of
the Grimes Colony in Ford's Colony, James City County. In addition to preservation of an existing
colony site and adjacent habitat, attempts will be made to move the remaining plants located in the
reservoir pool area to suitable locations.
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7.9.3 COHOKE CREEK DOWNSTREAM WETLANDS
Approximately 186 acres of wetlands will be preserved in the riparian corridor of Cohoke Creek between
the new reservoir and the existing Cohoke Millpond. The cover types affiliated with the wetland system
downstream of the dam closely resemble those upstream in the project area. The downstream wetlands
possess a high level of ecosystem diversity. Their close proximity to the open water communities in the
new reservoir will also enhance habitat diversity and provide wildlife benefits to the existing downstream
ecosystem. The riparian corridor preservation area also includes 620 acres of uplands. Preservation of
these uplands will ensure that large blocks of contiguous forests are available for wildlife and improve
riparian habitat value for wetland species. In addition, preservation will allow succession of cut areas and
immature forests to their mature state, resulting in improved habitat for some wildlife species. Lastly,
preservation of this area will ensure that a vegetated wildlife corridor is maintained between the reservoir
and Cohoke Millpond. King William County has a right to build a future dam downstream of the
currently proposed dam site (KWR-IV) as stated in the host agreement; however, the KRWSG is unaware
of any plans to develop a downstream impoundment on Cohoke Creek. King William County is currently
slated to receive an allotment of the reservoir's safe yield to meet their projected water needs; therefore, if
expansion of the King William Reservoir is pursued, it would occur well in the future. Construction of
another dam would require permit approval from the Corps and the State.
7.9.4 WETLAND EDUCATION
The RRWSG is engaged in consultations under Section 106 of the National Historic Preservation Act
with the Pamunkey and Mattaponi Indian Tribes, the COE and other agencies, aimed at designing
appropriate mitigation for potential impacts to tribal cultural resources. Under consideration are possible
financial or other support for such activities as developing Tribal environmental regulations, training and
education of Tribal members in environmental sciences, particularly wetlands, developing a database
describing specific wetland parameters associated with wetlands on the Tribes' Reservations, and
providing access to the wetlands by construction of elevated walkways and trails.
7.9.5 BEST MANAGEMENT PRACTICES FOR WATER QUALITY PROTECTION
Construction and land-clearing activities for the King William Reservoir, appurtenant features, and
mitigation components will require a significant amount of earth disturbing activities throughout the
various phases of the project. To ensure that minimum erosion and off-site transport of sediment occurs,
best management practices (BMPs) for construction activities will be strictly adhered and enforced.
BMPs will be incorporated into the Erosion and Sedimentation (E&S) plan for the project. Virginia's
E&S control programs are carried out cooperatively by state and local government agencies, pursuant to
the minimum standards contained in the Virginia Erosion and Sediment Control Law. The Virginia
Department of Conservation and Recreation (VDCR), local governments, and Soil and Water
Conservation Districts share responsibility for E&S controls. Localities must adopt the State plan or
create their own using the minimum standards. The RRWSG will be required to submit erosion and
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sediment control plans and demonstrate compliance with applicable E&S controls to obtain permits from
the Counties in which work is to be conducted.
7.10 SUMMARY
Implementation of the RRWSG's Mitigation Program will compensate for impacts by achieving "no net
loss" of wetland acreage or functions, and provide effective mitigation for other expected and potential
environmental impacts of the King William Reservoir project. The wetland mitigation component of the
Reservoir Mitigation Plan exceeds the requirements of the USCOE Norfolk District Regulatory Branch's
Wetland Mitigation Policy by 137 acres or 20 percent, by providing 2:1 restoration/creation for wetland
acreage impacts within the pool area. Losses in wetland function will be offset by this wetland
construction. Additional compensation will be provided by wetland preservation, lacustrine habitat
creation, shoreline habitat creation, stream corridor restoration, upland restoration and preservation, and
fisheries improvements. The RRWSG's Mitigation Program is generous, and it is unprecedented in both
its scope and the level of detail provided for a pre-permit proposal.
The project will benefit the public interest in numerous ways, in addition to its primary purpose of
meeting the long-term public water supply demands of the Lower Peninsula. It will benefit the host
communities, it will create new recreational opportunities, and it will benefit wildlife and fisheries. It will
also benefit the natural community in numerous ways, including permanent conservation of large upland
and wetland areas, and other elements that substantially exceed mitigation criteria normally applied to
impacts from construction of a reservoir.
In addition to the habitat provided by the wetland creation/restoration sites the King William Reservoir
itself will provide 1,526 acres of open water and shoreline habitat. Of those 1,526 acres, approximately
1,251 acres of new open water with depths greater than 6 feet will be created that will provide habitat for
freshwater fish, invertebrates, and migratory waterfowl.
Approximately 322 acres of shoreline wetlands and vegetated shallows are expected to develop between
the 90 and 97-foot contours of the 77-mile reservoir shoreline. These wetlands and shallow water areas
are valuable to fish and wildlife species that utilize shoreline habitat. The reservoir will also provide
substantial recreational opportunities in King William County.
The wetland compensation component of the Mitigation Program includes preservation of approximately
300 acres of existing wetlands adjacent to wetland mitigation sites. The plan also includes restoration,
restriction, and/or preservation of approximately 2,900 acres of uplands to serve as buffers around the
reservoir and wetland mitigation areas.
In summary, the Reservoir Mitigation Plan includes creation, restoration, enhancement, and preservation
of over 1,700 acres of wetlands, more than offsetting impacts to wetlands within the King William
Reservoir project area. The plan also provides for the restoration or creation, and preservation of more
than 4,751 acres of uplands and open waters, among other elements that have been incorporated into the
project planning and design to assure the fullest feasible mitigation of expected and potential
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environmental impacts. Detailed analysis demonstrates that these compensation elements will offset the
acreage and functional impacts of the various habitats lost to project construction. Successful
implementation of the Mitigation Plan therefore will accomplish the goal of assuring "no net loss" of
wetland acreage and function, and provide effective mitigation for other expected or potential
environmental impacts of the King William Reservoir project.
7.11 REFERENCES
American Water Works Association (AWWA). 1994. Expediting Water Projects: Benefits Assessment
and Wetland Mitigation Banking. Denver, CO. Prepared for the American Water Works
Association.
Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report
Y-87-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.
Garman, G.C. 1997a. Analysis of Potential Effects of Water Withdrawal for the King William Reservoir
on American Shad (Alosa sapidissima) and Related Anadromous Clupeid Fishes in the Mattaponi
River, Virginia. August 7, 1997. Prepared for Malcolm Pirnie, Inc.
Garman, G.C. 1997b. Qualitative Assessment of Instream Habitat Quality of Cohoke Creek (King
William County, Virginia) for Anadromous Clupeid Fishes (Alosa spp.) September 18, 1997.
Prepared for Malcolm Pirnie, Inc.
Jenkins, R.E. and N.M. Burkhead. 1993. Freshwater Fishes of Virginia. American Fisheries Society,
Bethesda, Maryland.
Jensen, J.R., S. Narumalani, O. Weatherbee, and K.S. Morris, Jr. 1992. Predictive Modeling of Cattail
and Waterlily Distribution in a South Carolina Reservoir using GIS. Photogrammetric
Engineering and Remote Sensing, Vol. 58, No. 11. November 1992. pp 1561-1568.
MAAR Associates. 1996. Phase I Cultural Resource Survey for the Proposed King Willam Reservoir,
King Willam County, Virginia and a Background Review, Architectural Survey and
Archaeological Reconnaissance for the Proposed Black Creek Reservoir, New Kent County
Virginia. Prepared for Malcolm Pirnie, Inc.
Malcolm Pirnie, Inc. 1997a. Draft King William Reservoir Wetland Mitigation Plan. Prepared for the
Lower Virginia Peninsula Regional Raw Water Study Group.
Malcolm Pirnie, Inc. 1997b. King William Reservoir Fringe Study. Prepared for the Lower Virginia
Peninsula Regional Raw Water Study Group.
Mitsch, WJ. and Gosselink, J.G. 1993. Wetlands. New York, Van Nostrand Reinhold.
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Rouse Environmental Services. 1996. Letter from Carrie D. Rouse to Thomas Sankey (Malcolm Pirnie,
Inc.). October 2, 1996.
Therres, G. D., M.A. Byrd, and D.S. Bradshaw. 1993. Effects of Development on Nesting Bald Eagles:
Case Studies from Chesapeake Bay. Trans 57th N.A. Wildl. and Natr. Resour. Conf. pp. 62-69.
U.S. Army Corps of Engineers (USCOE). 1984. Feasibility Report and Final Environmental Impact
Statement, Water Supply Study - Hampton Roads, Virginia. Norfolk, Virginia.
U. S. Army Corps of Engineers, Norfolk District. 1997. Final Environmental Impact Statement for
Lower Virginia Peninsula Regional Raw Water Supply Plan 1990-2040.
U. S. Army Corps of Engineers (USCOE). 1997. Letter from William Poore, Jr., Chief, Regulatory
Branch, to Malcolm Pirnie, Inc., August 4, 1997.
U. S. Environmental Protection Agency (USEPA) and the U.S. Department of the Army (Army). 1990.
Memorandum of Agreement (MOA) Between the EPA and Army Concerning the Determination
of Mitigation Under the Clean Water Act Section 404(b)(l) Guidelines.
U. S. Fish and Wildlife Service (USFWS) 1998. Letter from John O. Wolfm (Supervisor, Chesapeake
Bay Field Office) to Colonel Allan B. Carroll (District Engineer, Norfolk District, U.S. Corps of
Engineers). September 18, 1998.
Virginia Department of Conservation and Recreation (VDCR). 1991. Virginia Nontidal Wetlands
Inventory. (Richmond County and Northampton County data provided by VDCR on October 16,
2001.)
Virginia Department of Conservation and Recreation (VDCR). 1995. Letter from Carrie D.
Rouse to Thomas Sankey (Malcolm Pirnie, Inc.).May 1995.
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SECTION 8.0
PIRNIE
FUNCTIONAL ASSESSMENT
8.1 FUNCTIONAL ASSESSMENT DEVELOPMENT
8.1.1 INTRODUCTION
Wetlands are valuable natural resources, which perform several important functions. la 33 CFR 320.4 (b),
the important public interest functions performed by wetlands are identified as follows:
Food chain production
" General habitat, nesting, spawning, rearing, and resting sites for aquatic and upland species
Educational opportunities, refuges and sanctuaries
Sediment retention and stabilization
Shoreline erosion
Flood storage
Groundwater recharge and discharge
Water quality/water purification
This group of functions has traditionally formed the basis of functional assessment methods such as the
wetland evaluation technique (WET) and evaluation for planned wetlands (EPW) and are typical of the
ecological characteristics that are evaluated to determine the replacement value of a proposed wetland
mitigation plan.
8.1.2 FUNCTIONAL ASSESSMENT HISTORY
The functional assessment of the KWR mitigation plan has evolved over the last 10 plus years from early
studies that characterized the types of unavoidable wetland impacts produced by the project to a
generalized wetland functional overview, to finally, very specific wetland functional parameter
quantification. These actions and analyses have included:
Wetland delineation and classification from NWI mapping and aerial photography with field
verification.
WET functional assessment methodology.
Detailed on-site delineation with Cowardin classification.
EPW.
Flood-flow Alteration function quantified using HEC model.
HEP process to quantify wildlife impacts.
RRWSG commitment to 2:1 replacement to ensure "no net loss".
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Formation of a Mitigation Team to guide the selection of sites toward those having characteristics
similar to the impacted wetlands.
Consensus on 1:1 replacement ratio for hydrologic regime.
Mitigation Team consensus on 4 priority functions:
HEP for habitat quantification.
Ecosystem support as quantified by Total Net Primary Productivity (TNPP).
Water Quality as quantified by Sediment retention and Nutrient assimilation.
Landscape Interspersion and Connectivity evaluated by landscape position.
These analyses, actions and decisions shaped the initial site selection process and development of
mitigation strategies.
8.1.3 WETLAND EVALUATION TECHNIQUE
In April 1993, a functional evaluation was completed for wetlands in the impoundment area of King
William Reservoir. The Corps WET was utilized to assess the functions and values of the wetlands at the
proposed reservoir site (Adamus et al., 1987; Adamus et al., 1991). WET is an approach to wetland
evaluation that is based on predictors of wetland functions that can be gathered quickly. WET estimates
the probability that particular functions will occur in a wetland area and provides an estimate of the
importance of those functions.
The results of the WET assessment indicate that the palustrine system has a high probability of being
effective in providing floodflow alteration, sediment stabilization, sediment/toxicant retention, and
wildlife habitat. It has a moderate probability of providing groundwater discharge and production export
functions. It received low scores for groundwater recharge, nutrient removal/transformation, and aquatic
diversity/abundance.
While the WET assessment does have shortcomings, it was used early in the project's history to identify
wetland functions that would be impacted and therefore, would require mitigation. The WET technique
was only one of several functional assessments that have been completed for the reservoir project.
8.1.4 EVALUATION FOR PLANNED WETLANDS
A second method employed in the functional assessment of wetland impacts was the Evaluation for
Planned Wetlands (EPW), developed by Environmental Concern, Inc. (Bartoldus et. al., 1994). The EPW
format provides a quantitative evaluation of wetland values through analysis of six wetland functions:
shoreline bank erosion control, sediment stabilization, water quality, fish, wildlife, and
uniqueness/heritage.
In EPW, specific physical, chemical, and biological elements of the wetland or landscape are identified.
These elements are quantified by their relationship to a particular function and are combined in
assessment models to derive Functional Capacity Indices (FCIs). FCIs are multiplied by the size of the
assessed wetland to calculate Functional Capacity Units.
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The results of the evaluation indicated that the existing wetlands provide a high degree of sediment
stabilization and water quality functions and a moderate degree of wildlife and fish functions. A full
description of the EPW study is presented in the FEIS (USCOE, 1997).
8.1.5 HABITAT EVALUATION PROCEDURESGROSS LOSSES ANALYSIS
A multi-agency team that included state and federal agency representatives analyzed the project area of
the King William Reservoir using a recognized method of habitat analysis developed by the U.S. Fish and
Wildlife Service, the Habitat Evaluation Procedures (HEP). HEP is a method used to assess potential
impacts of projects to wildlife and develop compensation strategies for habitat losses associated with
project impacts. Habitat value is measured in the field to determine baseline conditions and then projected
over the life of the project to determine future conditions under various assumptions.
The KWR HEP study was conducted over a 3-year period by an interagency team of wildlife specialists
involved in the regulatory process for the reservoir. Team members included representatives from the
USFWS, the Corps, USEPA, Virginia Department of Environmental Quality (VDEQ), Newport News
Waterworks, and Malcolm Pirnie. Dean Stauffer with Virginia Tech was included in early 1997 as a HEP
expert to assist team members. Decisions throughout the study were made by consensus.
One objective of the HEP study was to provide a quantification of the habitat values lost as a result of
project implementation. This analysis, termed the gross losses, was based on the initial assumption that
the reservoir would provide no habitat value. The results provided a worst-case scenario of habitat loss,
but allowed the Mitigation Team to identify the greatest amount and type of mitigation that could be
required to offset the loss of habitat (Malcolm Pimie, 1999c). The remainder of the HEP study evaluated
the habitat gains provided by the open water of the reservoir, fringe and the developing project wetland
mitigation plan.
8.1.6 PRIORITY FUNCTION DEVELOPMENT
Based on the results of the WET, EPW, and HEP analyses, as well as the professional opinions of the
Mitigation Team, sites were evaluated for inclusion into the plan. Another important decision that was a
critical component of the plan to assure no net loss of functional value was the goal of replacing the
hydrologic regimes of the impacted wetlands at a minimum of a 1:1 ratio. That is, out of the 2:1
commitment of the RRWSG to replace wetlands, the Mitigation Team agreed that for the acreage lost, the
same hydrologic types (based on the Cowardin classification) would be replaced. The remaining 1:1
would not need to be in those same proportions. Additionally, the 2:1 commitment was made to provide a
margin of safety to assure no net loss.
The Mitigation Team agreed that the RRWSG needed to use a quantifiable method to evaluate the
functional losses and gains from mitigation plan implementation. At the Mitigation Team meeting of June
26, 1998, the Agencies and the RRWSG agreed that four primary wetland functions should be evaluated
by the RRWSG:
Habitat functions as evaluated by HEP.
ป Ecosystem support as quantified by total net primary productivity (TNPP).
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Water quality as quantified by sediment retention and nutrient assimilation.
Landscape interspersion and connectivity evaluated by landscape position.
Other functions such as flood-flow alteration, groundwater recharge and groundwater discharge were not
included because these functions were deemed to be not as critical as the four primary functions. The
RRWSG however has conducted detailed analysis for flood-flow alteration that is presented in the FEIS
(USCOE, 1997). Although this evaluation demonstrated that the flood-flow alteration function of the
wetlands in Cohoke Creek would be greatly offset by the King William Reservoir in this small drainage
basin, it was not considered a priority function and was not given further consideration.
The shoreline stabilization function was evaluated for inclusion. However, because the existing wetlands
on the Cohoke Creek site would be replaced by a reservoir, this function was not considered a priority
function. The shoreline will be replace by a reservoir that will capture any sediment released and
therefore there would be no loss to that function.
The groundwater recharge and discharge functions were also considered for further evaluation. However,
the increased permanent water levels will increase groundwater recharge significantly in the area as well
as increase groundwater discharge for base-flow support. Therefore, these functions were dropped from
further consideration.
8.2 PLANNED COMPONENTS
The components of the RRWSG's mitigation plan total approximately 6,100 acres of wetlands, uplands,
and open water to be restored, created, and preserved. The functional assessments demonstrate that the
mitigation strategies will more than offset the impacts associated with the 1,526-acre habitat conversion
for the project. Table 8-1 summarizes the functional replacement provided by mitigation plan
components.
8.2.1 WETLAND MITIGATION SITES
The wetland mitigation sites will offset the loss of the 403 acres of vegetated wetlands in the reservoir
pool, at a ratio of 2 acres for every acre lost (2:1 acreage compensation). Therefore, the plan will
restore/create a minimum of 806 acres of wetlands, and it includes a minimum of 1:1 compensation for
each affected vegetation cover type and hydrologic regime. The RRWSG has identified over 806 acres of
potential primary wetland restoration and creation areas within the York, Mattaponi, Pamunkey and
Rappahannock River Basins. These sites also contain wetland and upland buffer areas to enhance success
by minimizing disturbance to the wetlands from surrounding activities. The RRWSG has identified
approximately 290 acres of possible wetland mitigation as "contingency sites" that could be used to offset
the functional losses if one or more primary mitigation sites is reduced in final design, or if post-
construction monitoring indicates that a mitigation site is not achieving its established criteria. The
contingency mitigation acreage includes additional acreage that the RRWSG may restore/create on the
primary mitigation sites, if feasible. Table 8-2 lists acreages for the primary mitigation sites and
contingency sites.
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TABLE 8-1
Mitigation Component Functional Replacement
Mitigation Components ~f
Wetland Mitigation Sites
'w/wetland & upland restoration/preservation)
Deep water habitat
Shoreline wetlands and shallow water habitat
Downstream Preservation Area
Stream Corridor Restoration/Preservation
Fish Passage Restoration
Fish Hatchery Improvements
Wetland Education Opportunities
1,824
1,251
322
1,900
806
34 miles
1 of 3 alternatives
Coordinate w/
Tribes
Functional Replacement - -^ - -,, -- y,+* -^\ ^^-\ , ^ - ^ ' ,.. -, <^/*< - -
Water quality enhancement to the Pamunkey, Mattapom and Rappahannock Rivers and their tributaries through sediment retention and increased nutrient assimilation
Wetland systems and floodplain/npanan corridor restoration forming extensive ecosystem complexes integrated with high structural complexity and ecological value
Stream corridor restoration and stream restoration within mitigation sites and buffers
Floodflow alteration
Preservation and connection to large tracts of wildlife habitat providing corridors for wildlife movement
Floodflow alteration functions detention storage and hydrologic management preventing sediment loading and erosion to downstream areas, spawning and nursery, nesting, migratory, and
wintering areas for wildlife, supports recreational fishing, bald eagle habitat, recreational benefits
Floodflow alteration functions detention storage and hydrologic management preventing sediment loading and erosion to downstream areas
Spawning and nursery, nesting, migratory, and wintering areas for wildlife
Supports recreational fishery
Provides bald eagle habitat
Recreational benefits associated with camping, nature trails/hiking, picnic areas, bird watching, boating, fishing
Vegetated shoreline wetlands provide habitat for many aquatic and semi-aquatic species
Enhance ecosystem support and water quality functions associated with the reservoir
Stabilize the shoreline from erosional effects associated with wind and wake
Buffer will shield large tracts of upland habitat from logging and development and preserve this habitat tor wildlife species dependent on large tracts of temperate forest for breeding
Buffer preservation counters an overall, long-term trend towards greater forest fragmentation and reduction in forest habitat resulting from timbering and urbanization
Likely to benefit the ong-term breeding success of neotropical migratory songbirds
Provides large blocks of contiguous forests available for wildlife and maintains a vegetated wildlife corridor between Reservoir and Cohoke Millpond
Improves riparian habitat value for wetland and other wildlife species by precluding impacts associated with loggmg/clearcutting
Restoring stream bottoms and bank stabilization to reduce sedimentation and improve fisheries habitat
Improve water quality
Forested riparian buffers will serve as filters that control runoff and groundwater flow into streams, trap, filter, and convert sediments, nutrients, and chemicals, and maintain stream bank
stability and channel capacity
Buffer habitat provides shade, temperature control and food required by aquatic species and wildlife, and provide corridors for wildlife movement
Grass filter strips control pollutants in runoff by trapping and filtering sediments, pesticides, nutrients, and chemicals by maintaining soil stability
Restore anadromous fish habitat, spawning and nursery areas
An effort to increase anadromous fish stock in the greater York watershed
Supporting Tribal environmental regulations, training and education in environmental sciences, recreational uses of wetlands on Tribes' Reservations
' Source Fish and Wildlife Mitigjliun Pbn (Mav 1999)
-------
TABLE 8-2
Acreage Estimates for the Wetland Mitigation Sites and Contingency Sites
IVflTIGATION SITES:-:' .- '. :y" * *? "
York River Mitigation Bank
Burlington
Davis
Gulasky
The Island
KWFarm
Lanesville
Meadow Farm
Rice
Terrell
Townsend
Total =
f; ;: / / \ .-> EURWSG Estima|ejpr:. , ; ^ ^X^t
;., '., '; ' :J - .,t!Restoraflpn/Cr'eatiolri|.' '^A^ ,'J: -
'<;"" ''-',,-'"' "'- i;'ซr" '(acres)'- .'' - './--.;."
161
24
10
45
86
35*
37
63
33
195
117
806
ADDITIONAL CONTINGENCY SITES
Eocene (King William Co.)
Myers (Hanover Co.)
York River Mitigation Bank
New Kent Environmental Bank
Primary Mitigation Site Expansion
Subtotal =
TOTAL =
15
35
83
80
84
297
1,103
* Includes 4:1 ratio for wetland enhancement (4 acres @ 4:1 = 1 acre) combined with 34 acres of PC restoration
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FUNCTIONAL ASSESSMENT
The majority of selected wetland mitigation areas are located adjacent to streams or rivers.
Implementation of the mitigation plan would re-establish and/or preserve large wetland systems and
floodplain/riparian corridors forming extensive ecosystem complexes integrated with high structural
complexity and ecological value. Restoring these areas would provide floodflow alteration and water
quality enhancement to the Pamunkey, Mattaponi and Rappahannock Rivers and their tributaries through
sediment retention and increased nutrient assimilation. Preservation of these systems would connect large
tracts of wildlife habitat providing corridors for wildlife movement. Table 8-3 summarizes the functions
provided by each of the mitigation sites.
8.2.2 DEEP WATER HABITAT
The King William Reservoir will provide 1,526 acres of valuable open water and shoreline habitat, more
than compensating for the impacts to 34 acres of open water inundated in the pool area. Of that, 1,526
acres, approximately 1,251 acres of new open water with depths greater than 6 feet will be created and
will provide habitat for freshwater fish, invertebrates, and migratory waterfowl. The reservoir will have a
maximum depth of 68 feet, a mean depth of 25 feet, and a total water volume of approximately 12.2
billion gallons.
Conversion of existing wetland habitat in the pool area to a lacustrine system will provide several new
functions while maintaining many existing functions. The project will provide detention storage and
hydrologic management during storm events to prevent sediment loads and erosion of downstream areas.
These flood retention and storage functions are analogous to flood detention functions performed by the
existing wetlands in the pool area. A detailed description of this reservoir flood flow alteration function is
provided in the Main Report (Volume II) of the Final Environmental Impact Statement (USCOE, 1997).
Reservoir construction and filling will result in a conversion of habitat from upland forests and wetlands
to an aquatic open water system. The existing wildlife species composition will change to a community
that benefits from the reservoir and shoreline area. The reservoir will provide spawning and nursery,
nesting, migratory, and wintering areas which will receive significant use by a variety of waterfowl,
wading birds, amphibians, and other aquatic organisms. The habitat benefits of the reservoir may be
especially significant for the bald eagle, which is federally listed as "threatened" under the Endangered
Species Act. The reservoir will provide extensive open water foraging habitat, surrounded by 77 miles of
shoreline with large diameter trees suitable for eagle nesting, roosting, and perching sites.
A fisheries management program will be implemented to include supplementary stocking of forage and
game species to augment natural populations. The reservoir will also provide extensive recreational
opportunities such as camping, nature trails/hiking, picnic areas, bird watching, and boating.
8.2.3 SHORELINE WETLANDS AND SHALLOW WATER HABITAT
Approximately 322 acres of vegetated wetlands and shallow water habitat would potentially develop
around the 77-mile reservoir shoreline between the 90 and 97-foot contours. The King William Reservoir
- Reservoir Fringe Study (Malcolm Pirnie, 1997) provided a qualitative assessment of expected shoreline
wetland establishment. The vegetated shoreline wetlands expected to develop around the reservoir will
provide habitat for many aquatic and semi-aquatic species, as illustrated in the HEP Study (Malcolm
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-5
REGIONAL RAW WATER STUDY GROUP 3114-017
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TABLE 8-3
Mitigation Site Functional Replacement
MITIGATION SIT'S
>: \iRes torationfc.
Wetland^Preser^atton
"'>r""*'i""
'. ''^^ r" :i'^y: "xSi" ' i-'f?iji^ *
Upland Restoration/ Preservation
(AC)
Functional Replacement Goats
York River Mitigation
Bank
161
161
Water quality enhancement in the Pamunkey River basin, to include taking farm field
and pasture out of production and restoring forested riparian buffers, wetlands, and
forested upland buffers to serve as filters, eliminates sediment runoff,
fertilizer/pesticide runoff associated with agricultural activities
Floodplain/riparian corridor restoration; Ideal landscape position for forming and
extensive ecosystem complex on the Pamunkey River by connecting large
wetland/riparian corridor
Potential for >2 miles of stream corridor restoration (proposed with York River
Mitigation Bank)
Floodflow alteration
Restores and connects extensive corridor for wildlife movement, provides large tracts
of habitat preserved in perpetuity
Burlington Farm
24
17
41
Water quality enhancement in the Mattaponi River basin, to include taking farm field
out of production; eliminates sediment runoff, fertilizer/pesticide runoff associated
with agricultural activities
sites, provides protected corridor for wildlife movement between these mitigation
sites
Davis
10
24
42
Restoration of wetland/riparian complex connecting to exting forested stream/riparm
upstream and downstream of site
Water quality enhancement in the York River basin, to include taking farm fields out
of production; eliminates sediment runoff, fertilizer/pesticide runoff associated with
agricultural activities
Provides protected wildlife corridor for movement within stream/wetland
complexwatershed
Gulasky
45
28
127
200
Forms and extensive ecosystem complex on the Pamunkey River, provide riparian
habitat restoration, nutrient and sediment retention, wildlife habitat, farm fields and
pasture taken out of production
The Island
86
11
64
161
Create a unique wetland-upland ecosystem complex integrated with high structural
complexity and ecological value of the surrounding wetland system, provides
extensive tract of varying upland/wetland types within the Pamunkey River
floodplain, preclude mining operations, sediment retention and nutrient assimilation
associated with removal from agricultural operations, wildlife habitat
3114-017
June 2004
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TABLE 8-3 (cont'd)
Mitigation Site Functional Replacement
,?""* v ':' , , -'."'
MITIGATION SITES
KWFarm *
Lanesville
Meadow Farm
Rice
Terrell
Townsend
Subtotal
Restoration/Creatio
,;ซ'ป*-; tiap-'t - ' - -
<^,\?|nv-s ,,;',;
^fto -.;.-
35
37
63
33
195
117
806
Wetland Preservation"**^
- 4/>Jr'ฐ (AC)-. ." "'r'sti
38
11
17
202
0
0
Upland Restoration/ Preservation
(AC) ^''"
29
36
91
54
185
76
315 | 703
TOTAL WETLAND AND UPLAND MITIGATION =
Total
(AC)
105
84
171
289
380
193
1,827
"''^f:::,y Functional Replacement Goal '"',;
Floodplain restoration, BootSwamp Creek restoration, Mattapom River forested
riparian corridor restoration and conectivity to existing wetland systems, nutrient
assimilation and sediment retention, protection from mining operations, wildlife
habitat, farmland within floodplam taken out of production
Water quality enhancement through nutrient and sediment retention, farm fields taker
out of production, restoration of riparian habitat, stream corridor restoration/re-
establishment of a surface water connection , provides a complex of varying wetland
and upland communities/habitat
Farm fields, pasture land, and mined pits taken out of production, establish forested
wetlands along the Mattaponi River, stream corridor restoration associated with
Burlington Farm, water quality enhancement, floodflow alteration, wildlife habitat,
riparian buffer restoration/preservation
Floodplain restoration, Island mitigation site located immediately adjacent to site
combines to create an extensive wetland-upland ecosystem complex unique in
function and value due to the high structural complexity and ecological value of
adjacent forested wetland and Mattaponi River corridor, riparian corridor
restoration/preservation, nutrient assimilation and sediment retention, removes
floodplam from agricultural use, wildlife habitat
Water quality enhancement associated with Occupacia Creek and Rappahanock Rivei
by removing land from agricultural use, willdife habitat restoration, restoration of
fragmented riparian landscape, enhancement of floodflow attenuation, restore and
protect headwater wetlands
Headwater wetland restoration, stream corridor restoration, connectivity with forestec
riparian corridor to the north and south, large ecosystem complex, water quality
enhancement, wildlife habitat
* Includes 4 1 ratio for wetland enhancement (4 acres @ 4 I = I acre) combined with 34 acres of PC restoration
3114-017
June 2004
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FUNCTIONAL ASSESSMENT
Pirnie, 1999). These wetlands will also enhance ecosystem support and provide water quality functions
associated with the reservoir, to include shoreline stabilization.
8.2.4 RESERVOIR BUFFER AND UPLAND HABITAT PRESERVATION
Reservoir construction and filling will impact approximately 1,089 acres of uplands. To mitigate for this
loss of habitat, the RRWSG has proposed to restore, restrict, and/or preserve approximately 2,900 acres of
upland habitat. Of this, approximately 1,900 acres of upland forest will serve as a buffer for the reservoir.
The buffer consists of an area located adjacent to and extending 100 feet (horizontal distance) landward of
the reservoir pool area, which will be protected in perpetuity, and an additional 100-foot extended area
where land clearing will be limited and development taking place restricted. The buffer area will shield
large tracts of upland habitat from the current logging and development and preserve this habitat for
wildlife species dependent on large contiguous tracts of land. In addition, many neotropical migratory
song birds rely on large tracts of temperate forest for breeding. The upland restoration and preservation
projects will help to counter an overall, long-term trend toward greater forest fragmentation and reduction
in forest habitat resulting from timbering and urbanization, and therefore it is likely to benefit the long-
term breeding success of these species. Due to current logging pressures in the reservoir watershed, the
uplands preserved in the buffer area, upon reaching maturation, will surpass the quality of habitat
provided by the upland areas impacted by the reservoir.
8.2.5 DOWNSTREAM PRESERVATION AREA
Approximately 186 acres of wetlands will be preserved in the riparian corridor of Cohoke Creek between
the new reservoir and the existing Cohoke Millpond. King William County has a right to build a future
dam downstream of the currently proposed dam site (KWR-IV) as stated in the host agreement; however,
the RRWSG is unaware of any plans to develop a downstream impoundment on Cohoke Creek. King
William County is currently slated to receive an allotment of the reservoir's safe yield to meet their
projected water needs; therefore, if expansion of the King William Reservoir is pursued, it would occur
well in the future. Construction of another dam would require permit approval from the Corps and the
State.
The cover types associated with the wetland system downstream of the dam closely resemble those
upstream in the project area. The downstream wetlands possess a high level of ecosystem diversity. Their
close proximity to the open water communities in the new reservoir will also enhance habitat diversity
and provide wildlife benefits to the existing downstream ecosystem. The riparian corridor preservation
area also includes 620 acres of uplands. Preservation of these uplands will ensure that large blocks of
contiguous forests are available for wildlife and improve riparian habitat value for wetland species. In
addition, preservation will allow succession of timbered areas and immature forests to reach maturity,
resulting in improved habitat for some wildlife species. Lastly, preservation of this area will ensure that a
vegetated wildlife corridor is maintained between the reservoir and Cohoke Millpond.
8.2.6 STREAM CORRIDOR RESTORATION/PRESERVATION
Approximately 14.5 miles of first order stream, 3 miles of second order stream and 3.5 miles of third
order stream, for a total of 21 miles of streams will be flooded by the reservoir. Stream and riparian
corridor restoration, enhancement and preservation are included in the mitigation plan to offset these
losses. Based on mitigation ratios outlined in the joint state and federal agency stream mitigation
KING WILLIAM RESERVOIR MITIGATION PLAN page 8-6
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FUNCTIONAL ASSESSMENT
guidelines published by the Corps Wilmington District's stream mitigation, the project has identified in-
channel restoration or realignment for 4.4 miles of stream, enhancement of banks and/or riparian corridors
in 13.3 miles of stream and preservation of existing corridor for 19.5 miles for a total amount of stream
corridor improvement or preservation of 36.4 miles.
Restoration of impacted streams will be accomplished by various mechanisms that may include fencing to
prevent livestock from grazing along stream banks and entering streams, preservation, or other land use
restrictions. Riparian vegetation will be encouraged to reestablish, providing a mechanism for sediment
and nutrient removal from runoff and more favorable water temperatures. Bank stabilization and stream
bottom restoration will reduce sedimentation. These actions would yield water quality improvements that
would foster the return of rooted aquatic vegetation and enhance habitat quality for fish and invertebrates.
Establishing lengthy, stream-side forested corridors will establish buffer habitat providing shade,
temperature control and food required by aquatic species and wildlife; and provide corridors for wildlife
passage. These forested riparian buffers will serve as filters for runoff and groundwater flow into
streams; trap, filter, and convert sediments, nutrients, and chemicals; and maintain stream bank stability
and channel capacity. In time, the quality of this restored habitat may approach the value of the area's
existing riparian forests. Grass filter strips would also be utilized to control pollutants in runoff by
trapping and filtering sediments, pesticides, nutrients, and chemicals by maintaining soil stability.
Quantification of the benefits to the water quality function (sediment retention and nutrient assimilation)
has not been conducted for the stream restoration component, however, this component provides
additional functional gain and an added margin of safety to assure no net loss of wetland functional value.
8.2.7 FISH PASSAGE RESTORATION
Numerous strategies were incorporated into the project design to avoid and minimize potential impacts to
anadromous fish within the Mattaponi River. Dr. Greg Carman's research showed that the upper reaches
of Cohoke Creek (i.e., above the Cohoke Millpond Dam, including the entire reservoir pool area) would
be an unlikely candidate for anadromous fish passage restoration even without a major new reservoir.
Nevertheless, the RRWSG is working with the Virginia Department of Game and Inland Fisheries
(VDGIF) to identify one or more priority streams in the York River Basin for fish passage restoration.
Streams targeted for fishways are historically known to provide anadromous fish habitat. Several dams
are currently being evaluated.
Fish passage implementation would restore anadromous fish habitat, spawning and nursery areas.
Although the habitat value of the fish passage component has not been quantified, this component would
provide additional functional gain and provide an added margin of safety to assure no net loss of wetland
functional value.
8.2.8 FISH HATCHERY IMPROVEMENTS
To increase the stock of anadromous fish in the greater York River watershed, the Pamunkey and
Mattaponi Indian Tribes are seeking to upgrade their existing fish hatcheries, on the Pamunkey and
Mattaponi Rivers, respectively. The RRWSG is engaged in consultations under Section 106 of the
National Historic Preservation Act with the two Tribes, the Corps and other agencies. This consultation
could lead to actions taken by the RRWSG, which include possible financial support for fish hatchery
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-7
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MAUOOLM
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FUNCTIONAL ASSESSMENT
improvements as mitigation for potential impacts to Tribal cultural resources. These efforts would
increase anadromous fish stock in the greater York watershed.
8.2.9 WETLAND EDUCATION OPPORTUNITIES
The RRWSG has offered to provide possible financial or other support for such activities as developing
Tribal environmental regulations, training and education of Tribal members in environmental sciences,
particularly wetlands, developing a database describing specific wetland parameters associated with
wetlands on the Tribes' Reservations, and providing access to the wetlands by construction of elevated
walkways and trails. Although not recognized as a priority function, wetland education provides
additional functional value for public awareness and environmental stewardship.
8.3 ECOSYSTEM SUPPORT
8.3.1 PRIMARY PRODUCTIVITY
The interagency mitigation team, including representatives of the Corps, USEPA, USFWS, and the
VDEQ selected total net primary productivity (NPP) as one of the "priority functions" that the RRWSG
should assess to determine the potential environmental impact of the King William Reservoir Project.
Total NPP includes both aboveground and belowground NPP. NPP is a fundamental and measurable
function of ecosystem support that provides insight into the assimilation of carbon. Ecosystems
maintaining higher NPP values produce greater quantities of organic material for use as food and/or
habitat by other organisms. Defries et al. (1999), Mitsch and Gosselink (1986), Odum (1975), and
Schlesinger (1991) provide a review of NPP for different types of ecosystems and how changes in land
use affect NPP. The RRWSG used current and localized literature values and data, to the extent
practicable, to complete the NPP evaluation, and modified the assessment based on Corps review and
comments.
8.3.2 ASSESSMENT ASSUMPTIONS
The following primary production assumptions were applied to this functional assessment:
The King William Reservoir will provide 1,526 acres open water and shoreline habitat. Of that
1,526 acres, approximately 1,251 acres of new open water.
Existing terrestrial cover types within the reservoir buffer area are not included in this assessment
because these areas should experience little or no change in NPP.
Approximately 1,500 acres of existing terrestrial cover types on the mitigation sites will be
converted to wetland/aquatic or different terrestrial cover types.
Carbon mass is equal to 50 percent of total dry biomass (Birdsey 1992, Prince et al 1991).
High and low values for existing and proposed freshwater marsh NPP were acquired from Kvet
and Hasak (1978). Mitsch and Gosselink (1986) contains an extensive literature review of NPP
values for freshwater marshes and suggests that the values of Kvet and Hasak (1978) are
appropriate. It is assumed that the existing and proposed freshwater marsh systems possess NPP
values within these "high" and "low" ranges.
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-8
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MAlCOUVi
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FUNCTIONAL ASSESSMENT
High and low values for existing and proposed Forested Wetland NPP were acquired from Dabel
and Day (1977), Gomez and Day (1982), Megonical and Day (1988), and Powell and Day (1991).
Mitsch and Gosselink (1986) contains an extensive literature review of NPP values for forested
wetlands and suggests the above referenced values are appropriate. It is assumed that the existing
and proposed forested wetland systems possess NPP values within these "high" and "low" ranges.
" High and low upland forest values for NPP were acquired from temperate evergreen and
deciduous forest data, respectively, listed in Schlesinger (1991). The annual NPP of an evergreen
forest is typically greater than a deciduous forest, and it was assumed that the NPP of a mixed
forest would fall between the values associated with these forest types.
High and low agricultural values for NPP were acquired from Prince et al. (2001). However, in
agricultural production, much of the crop is removed for human and animal consumption.
Virginia Agricultural Statistics Service (2003), Bates (ND) and Kellogg Biological Station (2003)
were used to account for the amount of material removed for seed and silage. It is assumed that
agriculture in King William County will exhibit NPP values between those shown in Prince et al
(2001) and the information provided in, Virginia Agricultural Statistics Service (2003), and Bates
(ND) accurately reflect anthropogenic export of material which is available for ecosystem
support.
High and low NPP values for open water and the reservoir littoral zone were obtained from the
American Water Works Association (1994). Three reservoirs in neighboring southeastern states
were reviewed: Occoquan Reservoir, Virginia; Dog Lake, Georgia; and Falls Lake, North
Carolina. The highest and lowest values for open water NPP are associated with Occoquan
Reservoir and Dog Lake, respectively. Conversely, Occoquan Reservoir and Dog Lake exhibited
the respective lowest and highest values for littoral zone net primary productivity. It was assumed
that open water and littoral zone NPP would occur within this range of documented values.
8.3.3 METHODOLOGY
Existing and proposed NPP within the Cohoke Creek watershed, reservoir area, and mitigation sites were
estimated by multiplying the acreages of the various land use/cover categories by land-cover-specific
NPP estimates derived from peer reviewed literature. To compensate for variability within land use/cover
categories primary productivity caused by water and nutrient availability, species composition, landscape
position, climate and regional genotypes, a "high" and "low" NPP estimate was identified for each
category.
8.3.4 RESULTS
The NPP assessment concluded that the reservoir and mitigation sites would result in a net increase in
total NPP (Table 8-4). Specifically, the NPP between pre and post project conditions will be effected as
follows:
Total NPP will increase between 913 and 2,625 tons of carbon/year;
Terrestrial NPP will decrease between 1,234 to 1,629 tons of carbon/year; and
ป Aquatic NPP will increase between 2,147 to 4,304 tons of carbon/year.
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-9
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TABLE 8-4
Evaluation of Net Primary Production
,,
, '--i , '..-' . , -; ' '-:,
., ' '~ ; ' Existing ' ,, !
' Cover Types <"
Reservoir Area
Aquatic
Freshwater Marsh (PEM)1
Foreseted Wetlands (PFO and RFO)2
Open Water'
Aquatic Subtotal
Terrestrial
Upland Forest4
Terrestrial Subtotal
Total Reservoir Area
Mitigation Sites
Terrestrial
Agricultural Fields5
Upland Forest4
Total Mitigation Site Area
Total Aquatic
Tola! Terrestrial
TOTAL
Proposed
Cover Types
Reservoir Area
Aquatic
Littoral Zone3
Open Water3
Total Reservoir Area
Mitigation Sites
Aquatic
Freshwater Marsh (PEM)1
Forested Wetlands (PFO and RFO)2
Aquatic Subtotal
Terrestrial
Upland Forest*
Terrestrial Subtotal
Total Mitigation Site Area
Total Aquatic
Total Terrestrial
TOTAL
* , '>
. * * - . ,,, ' ' 'j
'. : ' ', ' ' ' '. '-;"*< V '
Net Change
Total Aquatic
Total Terrestrial
TOTAL
"''.'". "' ' ,
V'Area' '"
(acre)
87
317
34
437
1,089
1,089
1,526
1,443
66
1,509
437
2,598
3,035
Area
(acre)
275
1,251
1,526
87
720
806
703
703
1,509
2,332
703
3,035
- /' .
',: Are*,f
(acre)
1395
-1,895
0
Estimated ,
'- < Productivity ~--f
- iton:C ปcrej yr"') *
High
7.97
2.99
1.84
2.33
054
2.33
Low
1 00
224
0.39
2.15
0.28
2.15
Estimated
Productivity
(ton C acre"1 yr"1)
High
3.13
1.84
7.97
2.99
2.33
.',-, -X:~
Jv i:'-**
.',!,/ '
, a,.
""' ',','.
Low
2.80
039
1.00
2.24
2.15
,1
^ . .A
'**'"- :*
~'"~ *J
' ; ^ -.%
" "
Net Primary
>',- ProdurtivHy" '
(tonCyr-1)
High
689
945
63
1,697
2,537
2,537
4,235
779
779
1,697
3,317
5,014
' Low
86
709
13
808
2,341
2,341
3,150
404
404
808
2,745
3,554
Net Pr mary
Productivity
(ton C yr-1)
High
861
2,302
3,163
689
2,149
2,839
1,638
1,638
4,477
6,001
1,638
7,639
Low
770
488
1,258
86
1,612
1,698
1,511
1,511
3,209
2,956
1,511
4,467
,,, Net Primary
'*' Productivity
' , (tooCyr"1) V-
- High
4,304
>,- -1,679
;" 2,625
Low
I 2,147
;: -1034
913
' Kvet and Husak( 1978)
2Dabel and Day (1977), Gomez and Day (1982); Megomcal and Day (1988), and Powell and Day (1991)
3 American Water Works Association (1994)
4Schlesinger(1991)
! Bates (ND); Prince et al (2001), and Virginia Agricultural Statistics Sevice (2003)
3114-017
April 2004
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MAljQOyVt
PIRNIE
FUNCTIONAL ASSESSMENT
Quantification of the benefits to net primary production has not been provided for the additional
components of the mitigation plan such as the stream component. This component will provide an added
functional gain and provide an additional margin of safety to assure no net loss of functional value.
8.4 WATER QUALITY
8.4.1 SEDIMENT RETENTION AND NUTRIENT ASSIMILATION
Sediment retention and nutrient assimilation functions are directly related to water quality benefits
provided by wetlands. In this assessment, the functions are measured by the reduction in sediment and
nutrient loadings to Chesapeake Bay tributaries following project implementation and wetland mitigation.
The King Williams Reservoir project would change pollutant loading rates to the Chesapeake Bay by (1)
changing the proportion of different land cover types in the Cohoke Creek watershed and at mitigation
sites; (2) providing retention/assimilation of pollutants that enter the reservoir itself, both from runoff
from the surrounding watershed and from the Mattaponi River pumpover. Loadings of sediment,
nitrogen, and phosphorus loads were assessed for existing and proposed conditions from three sources:
Runoff and atmospheric deposition in the Cohoke Creek watershed.
Runoff in the mitigation site watersheds.
Mattaponi River pumpover to the Cohoke Creek watershed.
The RRWSG used current and localized literature values and data, to the extent practicable, to complete
the functional evaluation, and modified the assessment based on Corps review and comments.
8.4.2 ASSESSMENT ASSUMPTIONS
The following pollutant loading assumptions were applied to this functional assessment:
Under existing conditions, runoff to Cohoke Creek occurs in a 4,979-acre drainage area
comprising forestland, early successional logged areas, and agricultural fields. Under proposed
conditions, the drainage area contains the same cover types but is reduced to 3,890 acres because
of the increase in aquatic environments associated with the reservoir. As a result, smaller runoff
loads to the aquatic environment are expected under the proposed conditions.
Atmospheric deposition of nitrogen and phosphorous under existing conditions occurs on 34
acres of open water. Under the proposed conditions, this loading occurs on 1,526 acres due to the
increase in aquatic environments associated with the reservoir. As a result, increased direct
atmospheric deposition to open water would increase under the proposed conditions. I j
Airborne particulates are negligible. Sediment loading from atmospheric deposition therefore is
not included in this assessment.
Under existing conditions, the mitigation site contributing drainage areas include forestland and
agricultural fields. Agricultural fields within the wetland restoration/creation areas will be
converted to aquatic wetland systems (i.e., wetland mitigation sites) under the proposed
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-1 o
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FUNCTIONAL ASSESSMENT
conditions. In addition, an increase in forested land will result from upland restoration activities
on agricultural fields neighboring the proposed wetland restoration/creation areas.
" Because the intake will be located midway in the water column in the Mattaponi River, and water
will be pumped through intake screen slots one millimeter in diameter at a maximum intake
velocity of 0.25 fps at the face of the screen, particulate matter and sediment loadings to the
reservoir from this source will be negligible.
8.4.3 METHODOLOGY
Existing and proposed pollutant loads from the Cohoke Creek watershed, reservoir area, and mitigation
sites were estimated by multiplying the acreages of the various land use/cover categories by land-cover-
specific loading factors. The loading factors for forested land (including forested wetlands), agricultural
fields, and atmospheric deposition to open water were derived from results of the Phase 4.3 Chesapeake
Bay Watershed Model as compiled by the Chesapeake Bay Program Watershed Model Scenario Output
Database (http://wvvw.chesapeakebav.net/datahub.htm). Specifically, results for the "2000 Progress"
scenario for model segment 590 (which includes the proposed reservoir site) were used. Loads from this
scenario reflect the effects of agricultural and silvicultural best management practices (BMPs) in place in
the year 2000. Loading rates for inland freshwater marsh were provided bythe Corps (Corps, 2001).
To be conservative, this analysis did not explicitly estimate the retention/assimilation of sediments and
nutrients from uplands flowing to/through wetlands. Instead, the water quality benefits of wetlands were
considered by estimating the reduction in loads caused by conversion of other land types to wetlands, as
described above. In reality, loads from uplands might be reduced even further by retention/assimilation in
downgradient wetlands. However, it was not considered practical for the purposes of the functional
assessment to estimate the proportion of flows from uplands that would pass through adjacent wetlands in
a treatment-train fashion. This methodology causes the estimates of water quality benefits of the project to
be conservatively low.
Mattaponi River pumpover loading estimates for nitrogen and phosphorous were based on average
constituent concentrations at Scotland Landing listed in the Final Environmental Impact Statement
(Corps, 1997), and an average annual pumping rate of 14.5 millions gallons per day (MGD), which would
occur when the reservoir is at full safe yield capacity.
A sediment retention efficiency of 84 percent was utilized in this functional assessment for the reservoir,
based on the value for the Occoquan Reservoir as reported by AWWA (1994). Nitrogen and
phosphorous retention/assimilation efficiencies of 57 and 44 percent were used for reservoir systems,
based on average reservoir values report by AWWA (1994). These retention/assimilation efficiencies
were applied to all loads entering the reservoir from runoff, direct atmospheric deposition, and the
Mattaponi River pumpover.
Much of the water pumped into the reservoir from the Mattaponi River would ultimately be discharged to
the lower James River or Hampton Roads. This itself could be considered a water quality benefit, because
dissolved oxygen (D.O.) concentrations in the lower James River are less sensitive to nutrient loads than
in the lower York River, and the James River has less relative impact on D.O. concentrations in the
mainstem Chesapeake Bay due to its position near the Bay mouth (Butt and others, 2000). However, to be
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MAUOOLM
RRNIE
FUNCTIONAL ASSESSMENT
conservative, this functional assessment considered only the changes in pollutant loading in the project
vicinity, not the location of the loading.
8.4.4 RESULTS
The water quality assessment concluded that the reservoir and mitigation sites would result in a net
increase in sediment retention and nutrient assimilation (Table 8-5). Specifically, the project was
predicted to cause a:
742 ton/year reduction in sediment loads;
36,000 Ib/year reduction in total nitrogen loads; and
1,900 Ib/year reduction in total phosphorus loads.
Quantification of the benefits to the water quality function (sediment retention and nutrient assimilation)
have not been provided for the additional components of the mitigation plan such as the stream restoration
component. These components will provide an added functional gain and provide an additional margin of
safety to assure no net loss of wetland functional value.
WATER QUALITY ASSESSMENT SUMMARY
Sediment Loading
Reduction (tons/yr)
742
Nitrogen Loading
Reduction (Ib/yr)
36,000
Phosphorus Loading
Reduction (Ib/yr)
1,900
8.5 FISH AND WILDLIFE
8.5.1 OVERVIEW OF HEP
The Habitat Evaluation Procedures (HEP), a recognized method of habitat analysis developed by the U.S.
Fish and Wildlife Service, was utilized to evaluate fish and wildlife habitat impacts and gains from the
King William Reservoir project. A multi-agency team, formed in November 1995, analyzed the project
area of the reservoir to determine the value of habitat lost and typical value of habitat provided by the
mitigation components.
HEP is a method used to evaluate habitat quality, assess potential impacts of projects, and craft
approaches to compensate for habitat losses and to quantify changes to the quality of a particular habitat
as a result of land and water development projects. The habitat value is measured in Habitat Units (HUs),
which result from determining the habitat quantity (acreage) and quality. Habitat value was measured in
the field to estimate baseline conditions and then projected to determine future conditions under various
assumptions.
KING WILLIAM RESERVOIR MITIGATION PLAN
REGIONAL RAW WATER STUDY GROUP
Page 8-12
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TABLE 8-5
Evaluation of the Water Quality Functions of the King Willaim Reservoir Project
WATERSHED
(Cohoke Creek) (Proposed Reservoir)
Forested
Early Successional Logged Areas
Agricultural Fields
Total
PROPOSED RESERVOIR AREA
(Wetlands and Waters of the U.S)
Forested
Inland Freshwater Marsh
Open Water
Total
MITIGATION SITES
Forested
Agricultural Fields
[nland Freshwater Marsh
Total
Cover (Acres)
Existing
2,919
1,200
860
4,979
316
87
34
437
66
1,443
0
1,509
Proposed
2,044
986
860
3,890
0
0
1,526
1,526
1,423
0
87
1,509
Loading Rates
Sediment
(tons/ac/yr)
0.03
030
019
003
0.03
-
003
019
003
Nitrogen
(Ibs/ac/yr)
150
1300
1696
150
950
1012
1.50
16.96
950
Phosphorus
(Ibs/ac/yr)
002
0.20
136
002
060
0.57
0.02
136
060
Loads
Sediment
(tons/yr)
Existing
96
360
167
623
10
3
-
13
2
280
0
282
Proposed
11
47
27
85
0
0
-
0
47
0
3
50
Nitrogen
(lbป/yr)
Existing
4,379
15,600
14,586
34,564
474
822
344
1,640
99
24,473
0
24,572
Proposed
1,318
5,512
6,272
13,102
0
0
6,641
6,641
2,134
0
822
2,956
Phosphorus
(Ibs/yr)
Existing
64
240
1,170
1,474
7
52
19
78
1
1,962
0
1,964
Proposed
30
130
772
932
0
0
574
574
31
0
52
83
269
Change
Sediment
(tons/yr)'
-85
-313
-140
-538
-10
-3
-
-13
45
-280
3
-232
Nitrogen
s/yr)
-3,060
-10,088
-8,314
-21,462
-474
-822
6,296
5,001
2,035
-24,473
822
-21,617
-1 041
Phosphorus
{Ibs/yr)
-35
-110
-398
-542
-7
-52
555
496
30
-1,962
52
-1,881
-139
Notes
1 Forested land includes terrestrial forest, riparian forest, swamp, and scrub-schrub wetlands
2 Loading rates for agricultural, forest, and direct atmospheric deposition to open water based on output of the 2000 progress scenario of Chesapeake Watershed Model Phase 4 3 for model segment 590
3 Loading tales foi inland freshwater marsh based on USCOE (2001)
4 Proposed loads from reservoir watershed, reservoir area, and Mattaponi River pumpover consider reservoir assimilation/retention efficiencies of 0 84, 0 57, and 0 44 for sediment, nitrogen, and phosphorus, respectively
5 Reservoir sediment retention efficiency based on Occoquan Reservoir as indicated by A WWA (1994).
6 Reservoir nitrogen and phosphorous assimilation efficiencies (%) based on reservoir average values, AWWA (1994)
7 Mattaponi River loading rates based on concentrations at Scotland Landing presented in USCOE (1997), and an annual average pumpover rate of 14 5 MGD
3114-017
April 2004
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PIRNIE
FUNCTIONAL ASSESSMENT
The King William Reservoir HEP Study (Malcolm Pirnie, 1999) was conducted over a 3-year period by
an interagency team of wildlife specialists involved in the reservoirs regulatory process. HEP Team
members included representatives from the USFWS, the Corps, USEPA, Virginia Department of
Environmental Quality (VDEQ), Newport News Waterworks, and Malcolm Pirnie. Professor Dean
Stauffer of Virginia Tech was included in early 1997 as a HEP expert to assist HEP Team members. The
HEP Team cooperatively established working procedures and decisions throughout the study were made
by consensus. The HEP Team determined the main objectives of the KWR HEP study to be to:
Quantify aquatic and terrestrial habitat losses, for selected species, in the study area as a result of
reservoir construction.
" Guide the types of mitigation required to compensate for habitat losses in the study area.
Provide a tool for mitigation plan habitat evaluation.
The HEP Study determined the gross habitat losses from the reservoir construction and analyzed habitat
change resulting from reservoir construction. The Study also quantified the habitat gains provided by the
reservoir, fringe wetlands expected to develop along the reservoir shoreline, reservoir buffer, and six
mitigation sites that were determined to be a representative sample of the sum of the proposed mitigation
sites.
The HEP Study was consensus-driven. The evaluation period was limited to 50 years, and required that
potential compensation strategies be identified to "fully offset" habitat losses for all evaluated species.
8.5.2 HEP ANALYSIS OF THE MITIGATION PLAN
As stated above, the methodology developed by the HEP Study provided the RRWSG with a tool to
evaluate the mitigation plan components. Based on the results of the HEP analysis, an Average Annual
Habitat Unit (AAHU) was determined for each species based on a suite of mitigation sites that were
selected as representative sites for the King William Reservoir project. In the mitigation plan, the average
AAHU was applied to the full/final mitigation plan with a suite of sites that provide 806 acres of
restoration/creation. The proposed project would provide a net habitat gain for the majority of the
evaluated species. Habitat losses for all wetland dependent species would be offset by the mitigation
components. Habitat for many upland species would also be offset by the mitigation plan. Table 8-6
summarizes the HEP evaluation species habitat gains with implementation of the mitigation plan.
Habitat impacts to upland species requiring evergreen forests (represented by the pine warbler), early
successional logged areas (represented by the field sparrow), and large contiguous areas of mature forest
(represented by the pileated woodpecker) would not be fully offset by the mitigation plan during the
period of analysis (50 years). However, the plan does provide some level of compensation for these
species. Upland evergreen forest habitat and early successional logged area habitat is not quantity-limited
in Southeastern Virginia, and maintenance of these habitat types is not a recognized regional wildlife
objective.
The only fish species evaluated in the study was the redfin pickerel. This species was selected to represent
the slow-moving vegetated riverine habitat that currently exists in Cohoke Creek. The reservoir will not
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-13
REGIONAL RAW WATER STUDY GROUP 3114-017
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TABLE 8-6
HEP Evaluation Species Habitat Gains with Mitigation Implementation
Evaluation Species AAHU
Pool Area
Gross loss
- , - : - - _ Wetland-Dependent Species /-. ' " ''" ซ
', - Beaver '- ''-'
'" Mink'*::;- ""'":
' ':: Great Bine Heron
Wood Duck ;
.^ , f-**r W S.. [5^^' s^ s " "ซ
'" ' Red spotted Newt ,-;';V-
Vellowfhroat !, ,
-538
-675
-133
-72
-687
-133
; ;.,\ %|f f Othซi^ainiปttoซ SpraesV ."'"?%
/ : ' Plicated Woodpecker -fl"'
',;- Gray Squirrel
^,Mt **; J>ine:Warbiel$^-?:::" "
-' '-' "'Brown Thrasher ,.
C'^feFiddlSplrrow^ '"V ' .' '
Redfin Pickerel
-455
-426
-281
-35
-126
-125
AAHU
from
Reservoir
AAHU
from
Buffer
'~r4;k;-!"S;;'. -;*-> ^-^i
544
697
72
5
0
0
537
(a)
|K;;Vt;/hVr.^:^
0
0
0
0
0
0
(a)
407
(a)
(a)
(a)
437 ac wet
1089 ac up
275 acres
lacustrine
1990 ac up
Wetland
Restoration
and Creation
AAHU
per
acre
AAHU
for
806 ac
Upland
Restoration
AAHU
per
acre
AAHU
for
637 ac
Forested
Upland
Preservation
AAHU
per
acre
AAHU
for
66 ac
Forested
Wetland
Preservation
AAHU
per
acre
AAHU
for
315 ac
";'*'J ,v--:.''">''
215 '-''
' 239 '""' -
- 27 '''"';.
38'","":-'
- "" 358- s: '
"- 39 -,"'-'
^ ' " -V;'45*|>?f:"
- / -, "I . . - ,*X>.
*/;-.- LpSS,ซf-":>"-
, : 78'- -, '""'
0 ./ :f!S^ v
-------
MALGOUVt
PIRNfE
FUNCTIONAL ASSESSMENT
provide suitable habitat for this species, but it will provide valuable freshwater habitat for other fish
species that prefer a lacustrine environment and particularly a vegetated littoral zone.
The stream restoration element of the Mitigation Program will employ three types of mitigation:
restoration, enhancement, and preservation. Stream mitigation options can include stream buffers, water
quality improvement measures, and in-stream treatments and/or bioengineering measures (generally
excluding stormwater ponds). The goals of the stream and riparian corridor mitigation component are to
replace, to the degree practicable, the functions lost by flooding portions of Cohoke Mill Creek and its
tributaries. Stream restoration and enhancement will target stream systems that have highly eroded
banks; poor water quality, and provide a habitat of diminished quality for invertebrates, fish, and wildlife.
Mitigation would involve, in many cases, installing fences to keep cattle from grazing along the stream
banks and walking in the stream. In other cases, vegetation may be planted in the stream riparian zone.
Mitigation efforts will establish vegetation adjacent to the streams, which will provide cover for wildlife.
Vegetation also will provide shading and keep nutrients from entering the streams. Both of these factors
will improve water quality.
The stream corridor mitigation component will provide minimal redfin pickerel habitat compensation,
although this benefit was not quantified. In addition to the redfin pickerel, several other HEP evaluation
species, including the mink, beaver, and great blue heron, would benefit from the re-establishment of
vegetated riparian zones associated with stream restoration. Habitat for the redfin pickerel will be
increased through the improvement of water quality and the re-establishment of stream vegetation. Stream
restoration opportunities within the mitigation sites may provide additional redfin pickerel habitat. For
example, the York River Mitigation Bank includes over 2 miles of proposed stream restoration.
8.5.3 CONCLUSION
The HEP analysis of the King William Reservoir mitigation plan demonstrates that the mitigation
components will offset habitat losses for all wetland dependent species, as shown in Table 8-6. The plan
also offsets habitat losses for many of the upland evaluated species, and provides some level of
compensation for each evaluated species.
8.6 LANDSCAPE INTERSPERSION/CONNECTIVITY WITHIN THE PROJECT AREA
The project area consists of interspersed wetland cover types surrounded by a variety of upland habitats.
Maintaining extensive landscape interspersion and connectivity functions has been problematic
throughout all of eastern King William County, due to current agricultural and forestry practices (i.e., tree
farming and clear-cutting). The heavy logging pressures are due in part to its close proximity to the paper
mill in West Point. Downstream of the project area on Cohoke Creek, Cohoke Millpond blocks the direct
connection of the wetland/upland corridor to the Pamunkey River preventing the aquatic productivity of
upstream wetlands from being available to the downstream tidal Pamunkey River system.
8.6.1 OVERVIEW OF THE MITIGATION PLAN
The reservoir and mitigation sites provide for the preservation, in perpetuity, of large tracts of land in
areas that are currently farmed or subjected to periodic logging, including clear cutting. The reservoir and
buffer will provide approximately 3,500 acres of open water and valuable adjacent forested habitat. The
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FUNCTIONAL ASSESSMENT
reservoir and buffer area will connect with over 800 acres of wetlands and uplands preserved downstream
of the dam site providing habitat for species requiring large tracts of contiguous habitat Under the terms
of agreement between the applicant and King William County, the host jurisdiction, King William
County has a right to build a future dam downstream of the currently proposed dam site (KWR-IV). King
William County is currently slated to receive an allotment of the reservoir's safe yield to meet their
projected water needs; therefore, if expansion of the King William Reservoir is pursued, it would occur
well in the future. Construction of another dam would require permit approval from the Corps and the
State.
The mitigation sites will "meet the 2:1 replacement goal by providing 806 acres of wetland
restoration/creation, combined with over 300 acres of wetland preservation, and over 700 acres of upland
restoration and preservation. The majority of the wetland mitigation sites will include restoration and
preservation of riparian buffer areas adjacent to streams and rivers. Also, stream restoration will be
incorporated into the final design of several of the wetland mitigation sites. The sites provide connections
with existing forested wetland systems, thereby forming extensive ecosystem complexes consisting of a
variety of wetland, riverine, and forested upland habitats.
Figure 8-1 is a map of the Virginia Coastal Plain with the National Wetland Inventory (NWI) layer
"turned on" and enhanced with color (gold) to show how prevalent wetland systems are in this part of the
Virginia Coastal Plain and Chesapeake Bay region. The NWI mapping typically underestimates the extent
of wetlands in eastern Virginia. Figure 8-1 also shows how the wetland mitigation sites are located along
the river systems of this region.
After extensive investigation, it became evident that there simply were no opportunities for restoration of
damaged wetland systems within the small Cohoke Creek basin. Any on-site mitigation program would
have involved large-scale creation of wetlands that would have required significant soil and water
manipulation to insure success. As a result, the Norfolk District and other agencies made a decision early
on in the process to require the RRWSG to look beyond Cohoke Creek for possible mitigation sites.
Because 2:1 mitigation had been proffered, a minimum of 806 acres had to be found. The Mitigation
Team focused its search on prior converted croplands that had a riparian connection.
Figure 8-1 shows that six of the eleven sites lie along the Pamunkey River, the same sub-basin as the
impact area, Cohoke Creek. These six sites alone provide for no net loss of wetland acreage (1:1
replacement). Table 8-3 provides the total acreages for each of the mitigation sites. It can also be seen by
examining Figure 8-1 that in several cases, mitigation sites are in close proximity to one another. Most of
the sites are bordered by rivers or streams and experience occasional overbank flooding.
Focusing more closely, individual site maps are provided in Figures 8-2 through 8-9, including the
contingency site. These figures show the close proximity of some mitigation sites to other sites. These
larger scale maps, with the NWI-mapped wetlands shown in yellow, illustrate the connectivity the
mitigation sites provide to existing wetland and riparian systems.
8.6.2 CONCLUSION
In effect, the King William Reservoir project and its accompanying mitigation will involve an exchange
of 403 acres of wetlands that exhibit certain elements of separation from the downstream watershed by
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-15
REGIONAL RAW WATER STUDY GROUP 3114-017
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RNIE
FUNCTIONAL ASSESSMENT
the Cohoke Millpond for 806 acres of wetlands that are all directly connected to tributaries of the Bay.
This will provide environmental benefits to the Chesapeake Bay.
8.7 FUNCTIONAL ASSESSMENT CONCLUSIONS
The King William Reservoir compensatory mitigation plan represents the culmination of a lengthy,
complex process in which numerous federal and state agency representatives and. wetland mitigation
experts provided detailed analysis and review. The USEPA and USFWS concurred that the RRWSG
made a thorough and good faith attempt to assess the potential losses and gains of ecological functions
within the reservoir project area and mitigation areas. The RRWSG used current and localized literature
values and data, to the extent practicable, to complete the functional evaluations, and modified the
assessments based on Corps review and comments. The functional assessments indicate that the
mitigation components will more than offset the impacts, providing a margin of safely.
As mandated by the February 1990 "Memorandum of Agreement Between the Environmental Protection
Agency and the Department of the Army Concerning the Determination of Mitigation under the Clean
Water Act Section 404 (b)(l) Guidelines" (Joint MOA), the King William Reservoir mitigation plan
identifies appropriate and practicable methods and strategies that will be employed to offset impacts to
aquatic resources within the reservoir project area. Successful implementation of the compensatory
mitigation components will offset the adverse impacts of the proposed fill discharges to wetlands, and
provide compensation for other impacts within the project area. As stated in the NAD Corps September
2002 Decision Document regarding the RRWSG's proposed mitigation plan, " successful implementation
of compensatory mitigation resulting in no net loss of wetland functions and values would satisfactorily
offset the adverse impacts of the proposed fill discharge" (USCOE, 2002).
The interagency mitigation team, including representatives of the Corps, USFWS, and the VDEQ, was
closely involved in the process of mitigation site selection. The RRWSG has identified over 806 acres of
potential wetland restoration and creation areas within the Chesapeake Bay watershed that can be used to
offset the loss of 403 acres of vegetated wetlands within the reservoir pool area at a 2:1 compensation
ratio. All of the mitigation sites are located at appropriate geo-morphological landscape positions to
assure success and maximize in-kind functional replacement. Most of the mitigation sites are adjacent to
surface watercourses and extensive tracts of existing wetlands and uplands that will be protected and
preserved. A large majority of the wetland mitigation acreage consists of restoration of previously
degraded wetlands, which has proven to be the most successful type of mitigation.
The Corps, USEPA, USFWS and VDEQ defined the goal for the RRWSG's mitigation plan as "no net
loss of wetland acreage and function." Although the Joint MOA does not require full functional
replacement of each individual function that would be lost from implementation of the project, the
RRWSG has offered a mitigation plan that will more than offset the wetland acreage and functions lost
from the proposed project. The mitigation plan also offers other elements that are difficult to quantify, but
clearly add functional value to the project.
The 2:1 mitigation ratio is itself an appropriate and practicable way to compensate for the functional
differences in the Cohoke Creek wetlands and the mitigation sites-. As stated in the 1990 Joint MOA
between the Department of the Army and the USEPA,
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-16
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MA1COLM
PIRN!
FUNCTIONAL ASSESSMENT
"In the absence of more definitive information on the functions and values of specific wetland
sites, a minimum of 1 to 1 acreage replacement may be used as a reasonable surrogate for no net
loss of functions and values. However, this ratio may be greater where the functional values of
the area being impacted are demonstrably high and the replacement wetlands are of lower
functional value or the likelihood of success of the mitigation project is low."
The mitigation plan will restore/create 806 acres of wetlands to achieve 2:1 compensation, providing 403
acres of wetlands over and above 1:1 compensation. The 2:1 compensation was offered by the RRWSG
to ensure that the project's wetland impacts would be more than offset by the mitigation plan and to
provide full wetland functional replacement by offsetting the "lag time" for establishment of fully
functioning wetlands. In their May 28, 1998 comment letter, the USEPA acknowledged that the 2:1
mitigation ratio would "ensure adequate replacement of area-specific wetland functions" and further
stated, "A 2:1 ratio achieves full functional replacement in a shorter time frame and allows for less than
designed final function (per acre) in the event of a partial failure" (USEPA, 1998).
Recognizing that the selected mitigation sites were chosen for their excellent characteristics and their high
probability for wetlands establishment success, the 2:1 acreage replacement would achieve full wetland
functional replacement.
The rerservoir mitigation plan, when successfully implemented, will exceed the goal of compensating for
the loss of wetland acreage and function. The project will exchange 403 acres of wetlands that exhibit
certain elements of separation from the greater Chesapeake Bay Watershed by the downstream Cohoke
Millpond, for at least 806 acres of wetlands that are all directly connected to tributaries of the Bay.
The RRWSG is also committed to a program of stream restoration, enhancement, and preservation to
offset the losses associated with flooding of approximately 21 miles of nontidal, first, second, and third
order streams within the reservoir pool area, and to offset the loss of riparian habitat within the project
area. The project has identified in-channel restoration or realignment for 4.4 miles of stream,
enhancement of banks and/or riparian corridors in 13.3 miles of stream and preservation of existing
corridor for 19.5 miles for a total amount of stream corridor improvement or preservation of 36.4 miles.
The restoration effort will increase the value of habitat for fish and wildlife currently impacted by
agricultural activities and land development.
When combined with the reservoir, buffer, and downstream preservation area, the plan encompasses more
than 6,100 acres of preserved land, water and wetlands, which will be a significant contribution to the
Commonwealth of Virginia's efforts to restore and preserve the Chesapeake Bay and its tributaries.
8.8 REFERENCES
Adamus, P.R., E.J. Clairain, R.D. Smith, and R.E. Young. 1987. Wetland Evaluation Technique (WET),
Volume II: Methodology. Department of the Army, Waterways Experiment Station, Vicksburg,
MS. NTIS No. ADA 189968.
Adamus, P.R., L.T. Stockwell, E.J. Clairain, M.E. Morrow, L.D. Rozas, and R.D. Smith. 1991. Wetland
Evaluation Technique (WET), Volume I; Literature Review and Evaluation Rationale. Technical
Report WRP-DE-2, U.S. Department of the Army, Waterways Experiment Station, Vicksburg,
Mississippi. 287 pp.
KING WILLIAM RESERVOIR MITIGATION PLAN Page 8-17
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FUNCTIONAL ASSESSMENT
American Water Works Association. 1994. Expediting Water Projects: Benefits Assessment and Wetland
Mitigation Banking.
Bartoldus, C.C., E.W. Garbisch, and M.L. Kraus. 1994. Evaluation for Planned Wetlands (EPW).
Environmental Concern Inc., St. Michaels, MD. 327 pp. plus appen.
Bates, G. No Date. Corn Silage, Agricultural Extension Service of University of Tennessee.
Birdsey, R.A., 1992. Carbon Storage and Accumulation in United States Forest Ecosystems. USDA
Forest Service General Technical Report WO.59. August 1992.
Dabel, C.V. and P.P. Day Jr. 1977. Structural Composition of Four Plant Communities in the Great
Dismal Swamp, Virginia. Torrey Botanical Club Bulletin 104:352-360.
Gomez, M.M. and P.P. Day Jr. 1982. Litter nutrient content and production in the Great Dismal Swamp.
American Journal of Botany 69:1314-1321.
Institute for Water Resources Special Study. 2001. "An Evaluation of the Risk of Water Shortages in the
Lower Peninsula, Virginia" 70 p.
Kadlec, R.H. and Knight, R.L. 1996. Treatment Wetlands. CRC Press, LLC. 893 p.
Kellogg Biological Station. 2003. Long Term Ecological Research in Row Crop Agriculture.
http://lter.kbs.msu.edu/Date/table.jsp?Product=KBS019-003&order=asc&tools==show.
Kvet, J., and S. Husak 1978. Primary data on biomass and production estimates in typical stands of
fishponds littoral plant communities. In D. Dykyjova and J.Kvet, eds. Pond Littoral Ecosystems.
Springer-Verlag, Berlin.
Malcolm Pirnie, Inc. 1997. King William Reservoir - Reservoir Fringe Study. Report prepared for the
Regional Raw Water Study Group.
Malcolm Pirnie, Inc. 1999. King William Reservoir Project Habitat Evaluation Procedures: Main Report.
Report prepared for Regional Raw Water Study Group.
Megonigal, J.P. and P.P. Day Jr. 1988. Organic Matter dynamics in four seasonally flooded forest
communities of the Great Dismal Swamp. American Journal of Botany 75:1334-1343.
Mitsch, William J., and Gosselink, James G., 1993. Wetlands, Second Edition: New York, VanNostrand
Reinhold, 722 p.
Odum, E.P. 1971. Fundamentals of Ecology. W.B. Saunders Company, Philadelphia.
Odum, E.P. 1975. Ecology: The link between the natural and social sciences. Holt, Rineheart and
Winston, New York.
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FUNCTIONAL ASSESSMENT
Powell S.W. and P.P. Day Jr. 1991. Root Production in four communities in the Great Dismal Swamp.
American Journal of Botany 78:288-297.
Prince,S.D., J. Haskett, M. Steininger, H. Strand, and R. Wright 2001. NPP Cropland: Gridded Estimates
for the Central USA. Oak Ridge National Laboratory Distributed Active Archive Center,
Oakridge Term.
Schlesinger, W.H. 1991. Biogeochemistry - An Analysis of Global Change. Academic Press, New York.
U.S. Army Corps of Engineers, Norfolk District (Corps). 1997. Regional Raw Water Supply Plan Final
Environmental Impact Statement. Report prepared for the Regional Raw Water Study Group.
U.S. Army Corps of Engineers, Norfolk District (Corps). 2001. Analysis of Wetland and Habitat Impacts
and the Regional Raw Water Study Group's Proposed Compensation for the Proposed King
William Reservoir. 49 p.
U.S. Environmental Protection Agency and Department of the Army. 1990. Memorandum of Agreement
Between the Environmental Protection Agency and the Department of the Army Concerning the
Determination of Mitigation under the Clean Water Act Section 404 (b)(l) Guidelines
U.S. Environmental Protection Agency (USEPA). 1998. Letter from Roy E. Denmark, Jr. (Deputy
Director, Office of Environmental Programs, USEPA Region III) to Malcolm Pirnie. May 28,
1998.
Virginia Agricultural Statistics Service 2003. Virginia Agricultural Statistics Bulletin and Resources
Directory. Richmond, VA.
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SECTION 9.0
MAicoyvi
PIRNIE
ASSURANCES FOR
SUCCESSFUL IMPLEMENTATION
9.1 ASSURANCES FOR MITIGATION SUCCESS
The RRWSG has made every effort to minimize the risk involved with the mitigation proposals. Critical
elements of the plan must be reviewed and agreed uppn by the Corps and its advisory agencies before
proceeding. Similar requirements are already included in the project's Virginia Water Protection Permit
(VWPP). The RRWSG has allocated approximately 300 acres of contingency sites in the event that some
failure occurs, and most of the mitigation will be in place and subject to review and approval prior to the
impacts occurring. To further ensure success, enforceable provisions of the VWPP specifically require
success criteria, a monitoring program and contingency provisions to ensure that the entire mitigation
program is successfully established.
This plan will restore/create 806 acres of wetlands to achieve 2:1 compensation, providing 403 acres of
wetlands over and above 1:1 compensation. The 2:1 compensation was offered by the RRWSG to ensure
that the project's wetland impacts would be more than offset by compensatory mitigation projects and to
provide full wetland functional replacement by offsetting the "lag time" for establishment of fully
functioning wetlands.
9.1.1 U.S. ARMY CORPS OF ENGINEERS (CORPS) AND U.S. ENVIRONMENTAL PROTECTION
AGENCY (USEPA) MODEL COMPENSATORY MITIGATION PLAN CHECKLIST
The Corps recently released the "Model Compensatory Mitigation Plan Checklist for Aquatic Resource
Impacts" under the Corps Regulatory Program pursuant to Section 404 of the Clean Water Act and
Section 10 of the Rivers and Harbors Act. The document is intended as a technical guide for Clean Water
Act (CWA) Section 404 permit applicants preparing compensatory mitigation plans. In addition to
complying with the checklist items, the project will provide healthy sustainable wetland mitigation sites,
to the extent practicable, that compensate for the lost functions of the impacted wetlands and open water
in an appropriate landscape/watershed position.
9.1.2 REQUIREMENTS FOR COMPENSATORY WETLAND MITIGATION
The requirements for development of the wetland mitigation sites were derived from the Norfolk District
and Virginia Department of Environmental Quality (VDEQ) "Draft Recommendations for Compensatory
Wetland Mitigation" (July 2003), and encompass: requirements for final design plans and specs; success
criteria; potential permit conditions related to construction; monitoring; bonding; and restrictive language
for protection in perpetuity. The requirements will guide development and implementation of site-
specific compensatory wetland mitigation plans following permit issuance. The requirements may be
modified on a site-by-site basis according to information provided during final mitigation site design (to
account for varying success criteria), and are worded to allow flexibility while maintaining oversight by
the Corps and VDEQ. Full compliance with the mitigation requirements and conditions should guarantee
success of the mitigation sites.
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ASSURANCES FOR
SUCCESSFUL IMPLEMENTATION
9.1.3 20-YEAR MONITORING PERIOD
In addition to monitoring the wetland mitigation sites 3 consecutive years prior to site construction, the
RRWSG has committed to monitoring the wetland mitigation sites over a twenty-year period, following
the end of the first growing season. This lengthy monitoring commitment is unprecedented and
demonstrates the RRWSG's commitment to successful mitigation implementation.
9.1.4 CONTINGENCY MEASURES
In addition to providing wetland restoration and creation for 2:1 replacement, the RRWSG has identified
approximately 300 acres of potential wetland restoration/creation as "contingency acreage" that could be
used to offset the 2:1 replacement goal if one or more primary mitigation sites is reduced in final design,
or if post-construction monitoring indicates that a mitigation site is not achieving its establishment
criteria. The contingency mitigation acreage includes additional acreage that the RRWSG may
restore/create on the primary mitigation sites, if feasible, and two potential mitigation sites. Selection of
these contingency mitigation sites followed the same process used for the primary sites. Following field
investigations of the contingency sites in November 2003, the interagency team agreed to the
identification and use of the candidate and contingency mitigation sites,,and also agreed that the wetland
restoration/creation acreage proposed for the sites was conservative and would potentially provide
additional wetland mitigation acreage.
9.1.5 ADAPTIVE MANAGEMENT
The Corps and VDEQ or the permittee may, at any time during the monitoring period, require removal,
treatment or management of undesirable plant or animal species, including physical removal, use of
herbicides, live trapping, confining wires or nets, etc. Herbicide applications would be conducted in
accordance with all State/Federal application laws and regulations.
If the performance criteria are not met at any time during the monitoring period, the RRWSG would
provide the Corps and VDEQ with a proposal detailing corrective actions and/or maintenance actions
proposed (if any) and an implementation schedule for those actions. The RRWSG will implement the
necessary corrective measures following review and approval/modification of those measures by the
Corps and VDEQ. Upon completion of the corrective measures, the RRWSG will provide a written
summary of the work to the Corps and VDEQ. Additional remedial actions may be required/implemented
if the corrective measures do not result in satisfaction of performance criteria during the next subsequent
growing season.
9.1.6 VDEQ/USACE APPROVAL AND PUBLIC NOTICE
The final site-specific compensatory mitigation plans require approval by the Corps and VDEQ prior to
mitigation site construction. This review process will include public notice of the final mitigation plan.
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PIRN
ASSURANCES FOR
SUCCESSFUL IMPLEMENTATION
9.1.7 FINANCIAL ASSURANCES
Before any work may be conducted in wetlands, appropriate financial assurances guaranteeing the
successful establishment of mitigation will be required by the Corps and/or VDEQ. The financial
assurances will be conditioned upon performance of the mitigation and all required monitoring. The
financial assurances will be irrevocable for the period of performance. Financial assurances would be
released in annual increments upon attainment of specific restoration objectives or milestones (completion
of grading, planting, replanting, and first year monitoring). Since construction of the mitigation sites will
occur in tiers, financial assurance may transfer from one tier to another, or could be staggered from one
site to another based on an agreed upon level of completion. This will be determined by the permitting
agencies. The RRWSG shall assume all liability for accomplishing corrective work should the Corps and
VDEQ determine that the compensatory mitigation has not been completed satisfactorily.
9.1.8 PROTECTION IN PERPETUITY
A real estate instrument will be recorded in the chain of title to the subject property that will require the
preservation of the mitigation site (including wetlands) on the property in its post-construction/post-
restoration condition in perpetuity except for the work specified in the permit.
Land use will be limited by restrictive covenants and/or conservation easements. Conservation easements
are voluntary agreements to preserve land in perpetuity. Although filed with the deed, they do not
transfer land ownership, but rather spell out a landowner's commitment to protect the existing or
enhanced character of his property. This is a flexible concept, and the documents may be written to
protect land in accordance with a landowner's wishes.
Should the City of Newport News negotiate a fee simple purchase of the mitigation sites, conservation
easements could be given either to a qualified non-profit organization or a public body such as King
William County. The recipient of the easements will accept them in writing and agree to enforce the
terms of the easements to assure that future owners of the properties abide by them.
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SECTION 10.0
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MITIGATION COMMITMENTS
10.1 SUMMARY OF RRWSG MITIGATION COMMITMENTS
The following are mitigation commitments made by the RRWSG:
1. The RRWSG will be responsible for successful implementation of the wetland and stream mitigation
measures as described in the King William Reservoir Project "Reservoir Mitigation Plan." The Corps
of Engineers must provide written approval for the mitigation plan prior to the commencement of any
discharge of fill material which may be authorized by a Department of the Army permit. Approval
of the mitigation plan shall be prefaced by close consultation by the Corps with representatives of the
U.S. Environmental Protection Agency, Region III; U.S. Fish & Wildlife Service, Chesapeake Bay
Field Office, and the Commonwealth of Virginia Department of Environmental Quality. The same
interagency team will be utilized for assisting the Corps in making its decisions related to the
development of the implementation plan, monitoring, maintenance, long-term stewardship of the
mitigation properties, and any potential changes to the mitigation plan.
2. The RRWSG will provide 806 acres of restored and/or created non-tidal wetlands (2:1 acreage
compensation) to mitigate for 403 acres of permanent vegetated wetland impacts within the Reservoir
pool area, to include a minimum of 1:1 compensation for each affected hydrologic regime.
3.. Before any work will be conducted in wetlands, the following will be completed for each mitigation
site: a) compensatory mitigation design plans and construction specifications approved by the Corps
and VDEQ; b) proof of having secured the mitigation site (deed, easement, etc.); and c) proof of
appropriate financial assurances guaranteeing that the mitigation will be completed.
4. A boundary survey of the limits of planned wetlands within each mitigation site will be provided once
grading and planting are completed. This survey will be prepared by a licensed surveyor and certified
by the licensed surveyor or by a registered professional engineer or licensed landscape architect to
conform to the design plans and specifications. This requirement would be waived by the regulatory
agency where the limits of wetlands are clearly defined or associated with readily identifiable features
such as berms.
5. An as-built ground survey (or an aerial survey provided by a firm that specializes in aerial surveys)
will be conducted for each entire mitigation site, including invert elevations for all water elevation
control structures and spot elevations throughout the site. This survey will be prepared by a licensed
surveyor and certified by the licensed surveyor or by a registered professional engineer to conform to
the design plans and specifications. Submission of this survey will occur prior to release of the site
for seeding and release of that portion of the performance bond allocated to design and excavation
costs. The site will be seeded immediately following release of the site for seeding (i.e. within 7
calendar days) with an approved wetland seed mix to stabilize the site and to minimize invasion of
undesirable species. The Corps and/or VDEQ shall approve the as-built plan before release of the
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portion of the financial assurances allocated to design and excavation. For larger sites, this may
require that grading, surveying, submittal to the Corps and DEQ, and seeding is occurring on a
concurrent basis across the site.
6. The KRWSG will not plant the mitigation sites before the completion of the first three years of
hydrologic monitoring (during the fall to spring period) following grading. The RRWSG will submit
hydrological information for that period for Corps and/or VDEQ evaluation using groundwater wells
constructed and installed pursuant to a plan accepted by the Corps and VDEQ. That information will
be keyed to a site plan such that hydrologic conditions across the site can be evaluated and appropriate
vegetation can be selected which is compatible with the projected water elevations and duration.
Following evaluation of the hydrologic information, the Corps and/or VDEQ may require waiting
through an additional spring growing season in order to ascertain whether hydrology is sufficient to
meet the site's goals.
7. Wetland seed mixes and seed mixes used for control of soil erosion or to stabilize disturbed areas
anywhere in the vicinity of the mitigation sites shall be free of tall fescue, Bermuda grass, and other
allelopathic turf grass species, as well as plant species on the Virginia Department of Conservation
and Recreation's Invasive Alien Plant List.
8. The RRWSG will contact the Corps and/or VDEQ to discuss any substantive changes to the planting
plans (i.e. species composition, planting density) prior to implementing those changes. Any changes
would be confirmed in writing.
9. Following planting, the RRWSG will submit to the Corps and/or VDEQ a site plan (not necessarily a
survey) depicting actual plant zonation and a narrative documenting reasons for any changes from the
approved final design for each mitigation site.
10. For each mitigation site, the RRWSG will provide financial assurances, conditioned upon
performance of the required mitigation and all required monitoring. The financial assurances will be
irrevocable for the period of performance. A draft of the performance bond, letter of credit, or escrow
agreement will be forwarded for approval to the Corps' District's Office of Counsel prior to
execution. The Corps will receive the executed performance bond, letter of credit or escrow
agreement not less than 60 days before initiation of work in waters of the US (including wetlands).
Financial assurances will be released in annual increments upon attainment of specific restoration
objectives or milestones (completion of grading, planting, replanting, first year monitoring, etc.).
Since construction of the mitigation sites will occur in tiers, financial assurance may transfer from one
tier to another, or could be staggered from one site to another based on an agreed to level of
completion. This will be determined by the Corps.
11. A real estate instrument will be recorded in the chain of title to the subject property that will preserve
the mitigation site (including wetlands) in its post-construction/post-restoration condition in
perpetuity except for the work permitted herein. The RRWSG will coordinate with landowners of the
mitigation properties to identify an entity or organization that is committed, both by its mission and
financially, to the long-term stewardship of the mitigation property.
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MITIGATION COMMITMENTS
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12. No work will be conducted in wetlands until the Corps and VDEQ approves the real estate instrument
used to protect each mitigation site in perpetuity and proofs of recordation are submitted to the Corps
and VDEQ.
13. The site shall meet specified success criteria identified in Section 4.3 of this plan. (These criteria may
vary from year 1 to year 20, and variations will be specified in the site-specific plans for the
mitigation sites).
14. The Corps and VDEQ or the RRWSG may, at any time during the monitoring period of each
mitigation site, require removal, treatment or management of undesirable plant or animal species,
including physical removal, use of herbicides, live trapping, confining wires or nets, etc. Herbicide
applications will be conducted in accordance with all State/Federal application laws and regulations.
15. If the performance criteria of each mitigation site are not met at any time during the monitoring
period, the RRWSG would provide the Corps and VDEQ with a proposal detailing corrective actions
and/or maintenance actions proposed (if any) and an implementation schedule for those actions. The
RRWSG shall implement the necessary corrective measures following review and
approval/modification of those measures by the Corps and VDEQ. Upon completion of the corrective
measures, the RRWSG will provide a written summary of the work to the Corps and VDEQ.
Additional remedial actions may be taken if the corrective measures do not result in satisfaction of
performance criteria during the next subsequent growing season. Should the RRWSG fail to take
corrective action, the Corps/VDEQ may use the performance bond to fund the corrective actions.
16. Monitoring reports will be prepared for each mitigation site, and will follow the criteria identified in
Section 4.3.4 - Monitoring Report Criteria. Monitoring reports will show that minimum requirements
of special conditions and project plan have been met. The Corps and VDEQ will receive these reports
no later than December 1 of the monitoring year.
17. A pre-construction meeting between the Corps and VDEQ, the contractor/sub-contractors, and
equipment operators responsible for site preparation for each mitigation site will be held. The purpose
of this meeting will be to review the mitigation plans, including staging of site preparation; identify
areas to be avoided, handling of topsoil, etc.
18. The RRWSG will schedule a post-construction (post-grading) meeting to be attended by the Corps
and VDEQ. Any difficulties in construction will be identified during this meeting. Any apparent
problems will be corrected following the meeting.
19. A wetland professional, hired at the RRWSG's expense will conduct inspections of each mitigation
site at key milestones (i.e. grading, arrival of plant materials, during planting, etc.). Said wetland
professional will also conduct at least weekly inspections of the mitigation site during construction to
ensure that construction complies with plan design. The name and contact information (telephone
number, e-mail address, etc.) for this designated wetland professional will be provided to the Corps
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and VDEQ prior to commencement of work on the mitigation site. Any deviations in the plan will be
coordinated with and approved by the Corps and VDEQ prior to implementation.
20. The RRWSG will assume all liability for accomplishing corrective work should the Corps and VDEQ
determine that the compensatory mitigation has not been completed satisfactorily. Remedial work
may include regrading and/or replanting the mitigation site.
21. The RRWSG will be required to identify a reference wetland for each site to be used for monitoring
the mitigation site. The reference wetland will be accepted by the Corps and VDEQ and will not be
subject to any alterations during the monitoring period. Baseline data concerning vegetation and
hydrology will be provided to the Corps and VDEQ.
22. Credits from operational mitigation banks serving hydrologic unit code # 02080106 may be used to
complete the mitigation requirements (806 acres of creation/restoration) per approval by the Corps in
close consultation with representatives of the U.S. Environmental Protection Agency, Region III;
U.S. Fish & Wildlife Service, Chesapeake Bay Field Office, and the Commonwealth of Virginia
Department of Environmental Quality.
23. The RRWSG will submit a stream mitigation plan to the Corps prior to the start of construction at
Cohoke Creek. Stream mitigation will involve restoration, preservation, and enhancement of stream
and riparian corridors to offset the 21 linear-miles impacted within the reservoir area. The plan is
contained in Section 6 of this document.
24. The RRWSG is working with the Virginia Department of Game and Inland Fisheries (VDGIF) to
identify one or more priority streams in the York River Basin for fish passage restoration. Streams
targeted for fishways are historically known to provide anadromous fish habitat. The RRWSG will
provide funding for improved fish passage on the targeted stream. The Corps will consider assigning
stream mitigation credits for RRWSG fish passage restoration efforts in close consultation with
representatives of the U.S. Environmental Protection Agency, Region III; U.S. Fish& Wildlife
Service, Chesapeake Bay Field Office, and the Commonwealth of Virginia Department of
Environmental Quality.
25. The RRWSG will purchase and/or preserve wetlands adjacent to the wetland mitigation sites. The
final acreage of existing wetlands preserved will depend on individual purchase agreements with
landowners. However, it is expected that approximately 300 acres of natural wetlands adjacent to the
wetland mitigation areas will be preserved.
26. The RRWSG will restore and/or preserve several hundred acres of upland forest around the wetland
mitigation sites. The final acreage will depend on purchase negotiations with individual landowners.
The RRWSG will also preserve in perpetuity a 1,300-acre buffer around the reservoir and restrict
development within another 600 acres buffering the Reservoir.
27. The RRWSG has offered to provide financial or other support for such activities as developing Tribal
environmental regulations, training and education of Tribal members in environmental sciences
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particularly wetlands, and developing a database describing specific wetlands parameters associated
with the Tribe's Reservation.
28. A Mattaponi River Eco-Monitoring Plan will be developed following permit issuance. The plan will
be developed in coordination with VDEQ and the Corps. The purpose and goal of the plan is to
ensure protection of Mattaponi River flora and fauna during the implementation and operation of the
proposed King William Reservoir Project. Provisions will be made to monitor the composition and
distribution of flora in tidal freshwater wetlands and monitor the occurrence of salinity induced
changes to wetland communities and anadromous fish spawning/nursery grounds attributable to
Mattaponi River withdrawals, to include the following requirements:
> Sites in the vicinity of the intake and at designated locations upstream and downstream
along the Mattaponi River will be monitored for several environmental parameters.
> Provisions will be made to monitor water quality and marsh vegetation in tidal freshwater
areas, anadromous fish spawning and nursery grounds, and a nearby sensitive joint-vetch
colony.
> The monitoring protocol will be applied to a site on the Pamunkey River which will serve
as a control for biological and chemical components of the Mattaponi River.
> The final location of monitoring stations will be determined in consultation with the
VDEQ and public involvement as required in the applicant's VWP permit.
> Implementation of the ecological monitoring plan will begin at least eight years prior to
operation of the intake and continue for ten more years, although not every component
will be monitored each year.
> Anadromous fish spawning and nursery grounds monitoring will include pre-operational
ichthyoplankton surveys and entrainment ichthyoplankton surveys.
> Mitigation strategies for potential fisheries impacts will adhere to recommendations
provided in the King William Reservoir - Mattaponi River Fisheries Impact Assessment
and Mitigation Report (King William Reservoir Fisheries Panel, 2004).
> The State approved river monitoring plan must be in place prior to project operation.
29. A Mattaponi River Salinity Monitoring Plan will be developed following permit issuance. The plan
will be developed in coordination with the Corps and VDEQ.
30. The RRWSG will develop and implement a Drought Conservation Plan that will be developed in
coordination with the Corps and state agencies. The plan will include the following components:
a) Evaluation and determination of drought conservation measures.
b) Develop an Information and Education Program.
c) Monitoring of plan results.
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31. Best management practices including erosion and sediment control techniques will be implemented to
avoid and/or minimize environmental impacts associated with construction of the project.
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