V
United States
Environmental Protection
Agency
Office Of Water
Gulf Of Mexico Program
Stennis Space Center, MS 39529
EPA 800-B-94-006
July 1994
Freshwater Inflow
Action Agenda
For The Gulf Of Mexico
First Generation—Management
^±?
Committee Report
JLf-
Freshwater
Inflow
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Freshwater Inflow
Action Agenda
for the
Gulf of Mexico
Recycled/Recyclable
, ' Printed1 on paper' (tiat'oo'ntalns
' at least 50% recycled fiber
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Preface
PREFACE
One of the initial goals for the first five years of the Gulf of Mexico
Program was to establish a "framework-for-action" for implementing
management options for pollution controls, determining research
direction and environmental monitoring protocols, and implementing
remedial and restoration measures for environmental losses. As a means
of developing this framework-for-action, the Gulf Program established
eight committees, composed of experts, to deal with the following
environmental issue areas:
a Habitat Degradation
a Marine Debris
Q Freshwater Inflow
Q Nutrient Enrichment
a Toxic Substances & Pesticides
a Public Health
Q Coastal & Shoreline Erosion
Q Living Aquatic Resources
Each committee was charged with: 1) characterizing the status of the issue,
2) developing goals and objectives for remedial and restoration activities,
and 3) developing descriptions of the projects and tasks to be implemented
in order to achieve the stated objectives. This information was
incorporated into an "Action Agenda" for each environmental issue area.
This document is the first generation of one of these Action Agendas.
Representing the consensus of a large number of subject specialists, this
document is considered to be a draft working paper for the Gulf of Mexico
Program Management Committee. Since this first generation Action
Agenda has not been reviewed and approved by all agencies, it is being
made available for informational purposes only.
Gulf of Mexico Program Action Agenda
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Executive Summary
Executive Summary
The Gulf of Mexico contains ecological and commercial resources matched by few
other bodies of water. Yet its productive waters disguise the increasing
environmental threats that endanger these resources. In recognition of the growing
threats, Regions 4 and 6 of the U.S. Environmental Protection Agency (USEPA),
which share jurisdiction over the five Gulf Coast States (Alabama, Florida,
Louisiana, Mississippi, and Texas), initiated the Gulf of Mexico Program in August
1988. The goal of the Gulf of Mexico Program is to protect, restore, and enhance the
coastal and marine waters of the Gulf of Mexico and its coastal natural habitats, to
sustain living resources, to protect human health and the food supply, and to
ensure the recreational use of Gulf shores, beaches, and waters—in ways consistent
with the economic well being of the region.
The Gulf of Mexico Program is a cooperative partnership among federal, state, and
local government agencies, as well as with people and groups who use the Gulf.
During the early stages of Program development, eight priority environmental
problems were identified and the following Issue Committees have been established
to address each of these problems: Marine Debris, Public Health, Habitat
Degradation, Coastal & Shoreline Erosion, Nutrient Enrichment, Toxic Substances
& Pesticides, Freshwater Inflow, and Living Aquatic Resources. There are important
linkages among these various Issue Committees, and the Gulf of Mexico Program •
works to coordinate and integrate activities among them.
The Freshwater Inflow Committee was charged with characterizing the problems
associated with alterations to freshwater inflow into the Gulf and identifying
appropriate ways to protect these resources. The Issue Committee has been meeting
for more than three years—to review information and data collected by citizens and
scientists, identify problem areas, discuss actions that can resolve the problems, and
evaluate methods for achieving and monitoring results. The culmination of Issue
Committee efforts is this Freshwater Inflow Action Agenda which specifies an
initial set of activities needed to protect the Gulf of Mexico from freshwater inflow
concerns. This Action Agenda is the first generation of an evolving series of Action
Agendas that will be developed to meet the future needs of the Giilf of Mexico.
Chapter 1 of the Action Agenda provides an overview of Gulf of Mexico resources
and the threats now facing those resources. In addition, Chapter 1 describes the
structure of the Gulf of Mexico Program, including the Action Agenda development
process.
Chapter 2 describes the functional role of freshwater inflows relative to the ecology
of estuarine environments and the Gulf of Mexico.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Executive Summary
Chapter 3 describes the legal and institutional framework currently in place in the
Gulf of Mexico to address freshwater inflow issues and support efforts to provide
sufficient quantities of freshwater needed to maintain a healthy marine ecosystem.
Chapter 4, The Unfinished Agenda, contains the goal, objectives, and specific
activities established by the Gulf of Mexico Program to address freshwater inflow
issues. The long-term goal established by the Issue Committee is to:
Q Protect, preserve, restore, and, where feasible, enhance the freshwater
inflow to the Gulf of Mexico and the associated bays and estuaries for
the purpose of maintaining the ecological health and integrity of those
systems.
For the purposes of this Action Agenda, "freshwater" includes surface water, ground
water, springs, and precipitation.
Eighty-six action items have been developed to support the goal and these are
grouped under four types of activity and seventeen objectives (see Index of
Freshwater Inflow Objectives). The action items included in Chapter 4 have been
screened by the Gulf of Mexico Program and represent those activities that are
currently the most significant and most achievable. This is a fairly comprehensive,
but not exhaustive list. This document begins an evolving process of Action
Agendas in which action items are designated, implemented, and then reassessed as
progress in the Gulf is made. In the future, new action items will be developed to
meet the changing needs in the Gulf of Mexico.
Action items contained in Chapter 4 are not listed in priority order. Some of the
actions may already be underway but not yet completed. Others are included
because they will guide federal, state, and local government agencies and private
sector organizations in allocating resources where they are most needed and in
justifying future management strategies. This Action Agenda should prompt
specific agencies and groups to become involved.
The Gulf of Mexico Program recently developed ten short-term environmental
challenges to restore and maintain the environmental and economic health of the
Gulf. Within the next five years (1993-1997), through an integrated effort that
complements existing local, state, and federal programs, the Program has pledged
efforts to obtain the knowledge and resources to:
• Significantly reduce the rate of loss of coastal wetlands.
• Achieve an increase in Gulf Coast seagrass beds.
• Enhance the sustainability of Gulf commercial and recreational fisheries.
• Protect the human health and food supply by reducing input of nutrients, toxic substances, and
pathogens to the Gulf.
• Increase Gulf shellfish beds available for safe harvesting by ten percent.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Executive Summary
• Ensure that all Gulf beaches are safe for swimming and recreational uses.
• Reduce by at least ten percent the amount of trash on beaches.
• Improve and expand coastal habitats that support migratory birds, fish, and other living
resources.
• Expand public education/outreach tailored for each Gulf Coast county or parish.
• Reduce critical coastal and shoreline erosion.
This Freshwater Inflow Action Agenda supports these five year environmental
challenges.
For the public, the Gulf of Mexico Action Agenda should serve three purposes.
First, it should reflect the public will with regard to addressing freshwater inflow
concerns. Second, it should communicate what activities are needed to address
freshwater inflow concerns and provide the momentum for initiating these actions.
Third, it should provide baseline information from which success can be measured.
This Action Agenda is a living document; therefore, the Gulf of Mexico
Freshwater Inflow Committee intends to periodically revise and update this
document.
Index of Freshwater Inflow Objectives
Policy. Planning & Implementation
Objective: Develop a process for assessing the range of freshwater needs for estuarine and coastal waters of
the Gulf of Mexico and identify the quantity and quality of freshwater necessary to meet those needs.
Objective: Identify and evaluate Gulf of Mexico estuaries with freshwater inflow issues and select appropriate
estuaries for management attention.
Objective: Develop a coordinated Gulfwide strategy to provide adequate freshwater inflows to the estuarine
and coastal waters of the Gulf of Mexico.
Objective: Develop policy alternatives on the allocation of water among Gulf of Mexico estuaries.
Objective: Promote the watershed approach in national policy.
Research
Objective: Conduct research to improve the understanding of relationships among freshwater inflows,
salinity patterns, nutrient delivery and uptake, sediment regimes, circulation and flushing times, estuarine
productivity, and habitat (with an emphasis on major representative river systems) in the Gulf of Mexico.
Objective: Conduct research on the cumulative impacts of alterations on freshwater inflows to the Gulf of
Mexico.
Objective: Conduct research on population and economic projections in the Gulf of Mexico related to
freshwater needs and flows and related socio-political issues.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
iii
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Executive Summary
Index of Freshwater Inflow Objectives (continued)
Monitoring & Assessment
Objective: Inventory all available data and identify data gaps relating to water quality and quantity, water use
factors, and effects of freshwater inflow on Gulf of Mexico estuarine productivity—including salinity patterns,
nutrient delivery and uptake, sediment regimes, land use and land use changes, biological parameters,
geomorphology, and types of freshwater inflow (.e.g., surface water, ground water, and other sources).
Objective: Assess trends in freshwater inflows to the Gulf of Mexico.
Objective: Identify and evaluate causes of change in freshwater inflow quantity and quality relative to
location, volume, and timing of change within an estuary or segment in the Gulf of Mexico.
Objective: Determine Gulf of Mexico estuarine resource-based salinity requirements based on existing
knowledge and working hypotheses (inventory what has been done and identify what needs to be done for major
representative ecosystems).
Objective: Identify linkages and assess relationships among freshwater inflows, salinity patterns, nutrient
delivery and uptake, sediment regimes, estuarine productivity, other water quality parameters, and the adjacent
Gulf of Mexico.
Objective: Develop a Gulfwide monitoring program to assess the effectiveness of freshwater management
actions on an estuary specific (or estuary class) basis.
Public Education & Outreach
Objective: Promote the basin-wide public awareness of ecological, economic, and health impacts associated
with alterations of freshwater inflows to estuarine systems and the cumulative role of those estuaries for sustaining
the health of the Gulf of Mexico.
Objective: Promote the basin-wide awareness of federal, state, and local government officials and decision-
makers of the ecological, economic, and health impacts associated with alterations of freshwater inflows to
estuarine systems and the cumulative role of those estuaries for sustaining the health of the Gulf of Mexico.
Objective: Promote basin-wide public involvement to address the ecological, economic, and health impacts
associated with alterations of freshwater inflows to estuarine systems and the cumulative role of those estuaries for
sustaining the health of the Gulf of Mexico.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
iv
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Table off Contents
Table of Contents
List of Tables ..„ vii
List off Figures viii
1 OVERVIEW OF THE GULP OF MEXICO 1
The Gulf of Mexico -A Vast & Valuable Resource........................ 1
The Gulf of Mexico - A Resource at Risk... 4
The Gulf of Mexico Program - Goals & Structure 5
The Freshwater Inflow Committee..... 9
2 FRESHWATER INFLOW iN THE GULF OF MEXICO............... 11
Role of Freshwat&r Inflows in Estuarine Ecosystems........ 11
Salinity Characteristics of Gulf of Mexico Estuaries.......... 13
Other Factors Affected! by Freshwater Inflow............. 19
Quantity of Freshwater Inflows to the Gulf of Mexico 21
Factors Related to Changes In Streamflow. 33
Impacts of Alterations in Freshwater Inflows.................... 34
State-By-State Overview 37
Alabama[[[ 37
Florida......... 39
Louisiana[[[ 44
Mississippi 46
Texas 48
Case Studies on Trends 53
Conclusion[[[ 56
3 FEDERAL & STATE FRAMEWORK
FOR ADDRESSING FRESHWATER INFLOWS 57
4 THE UNFINISHED AGENDA 58
Goal[[[ 58
Objectives & Action Items 58
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Table of Contents
In Closing.
Bibliography 1OO
APPENDIX A Federal & State Framework 1O5
APPENDIX B Acronym Guide 128
APPENDIX C Glossary- •»» 13O
APPENDIX D Participants in the Action Agenda Development Process...... 136
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
vl
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List of Tables
List off Tables
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 2.S
Table 2.6
Table 2.7
Table 2.8
Estuary Types Based on Infra-Annual Salinity
Variability. 17
Periods of Record for USGS Dally Values
of Water Quality & Streannflow for the Lower
Reach of Major Streams that Discharge
Directly to the Gulf of Mexico 23
Drainage Areas & Gaged Drainage Areas to
the Gulf of Mexico 24
Selected Characteristics of the USGS Data
Base for Daily Values of Stream flow &
Dissolved Solids for Stream Gages Within
2OO Miles of the Gulf of Mexico 25
Selected Characteristics for Long-Term
Streamflow Gages on Streams Discharging
Directly to the Gulf of Mexico 27
Annual Mean Streamflow, in Cubic Feet
per Second, for Long-Term Gages in Texas,
1947-86.. 28
Annual Mean Streamflow, in Cubic Feet
per Second, for Long-Term Gages in Louisiana,
Mississippi & Alabama, 1947-86... 29
Annual Mean Streamflow, in Cubic Feet
per Second, for Long-Term Gages in Florida,
1947-86 3O
Gulf of Mexleo Freshwater Inflow Action Agenda (3.1)
vii
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U«t of Figure*
List of Figures
Figure 1.1
Figure 1.2
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 2.G
Figure 2.6
Gulf of Mexico Coastal Population per
Shoreline Mile 3
Gulf Program Structured Partnership..................... 7
Gulf of Mexico Estuaries 15
Estuary Types Based on Infra-Annual Salinity
Variability 18
General Variation of River Flow Around
the Gulf. 22
Conceptual Chain Reaction Between Spring
River Runoff & Some Major Chemical,
Physical & Economic Parameters In
Delta-Estuary-Sea Economy. 36
Coastal Zone of Texas Showing Major
Estuarine Systems 48
Location of Case Study Rivers................................ 54
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
viii
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Overview of the Gulf of Mexico
Chapter 1
OVERVIEW OF THE GULF OF MEXICO
The Gulf of Mexico - A Vast & Valuable Resource
Bounded by a shoreline that reaches northwest from Florida along the shores of
Alabama, Mississippi, and Louisiana, and then southwest along Texas and Mexico,
the Gulf of Mexico is the ninth largest body of water in the world. The Gulf's U.S.
coastline measures approximately 2,609 km (1,631 miles)~longer than the Pacific
coastline of California, Oregon, and Washington. The Gulf region covers more than
1.6 million km2 (617,600 mi2) and contains one of the nation's most extensive
barrier-island systems, outlets from 33 major river systems, and 207 estuaries (Buff
and Turner, 1987). In addition, the Gulf receives the drainage of the Mississippi
River, the largest river in North America and one of the major rivers of the world.
A cornerstone of the nation's economy, the Gulf's diverse and productive
ecosystem provides a variety of valuable resources and services, including
transportation, recreation, fish and shellfish, and petroleum and minerals.
Encompassing over two million hectares (five million acres) (about half of the
national total), Gulf of Mexico coastal wetlands serve as essential habitat for a large
percentage of the U.S.'s migrating waterfowl (USEPA, 1991). Mudflats, salt marshes,
mangrove swamps, and barrier island beaches of the Gulf also provide year-round
nesting and feeding grounds for abundant numbers of gulls, terns, and other
shorebirds. Five species of endangered whales, including four baleen whales and
one toothed whale, are found in Gulf waters. These waters also harbor the
endangered American crocodile and five species of endangered or threatened sea
turtles (loggerhead, green, leatherback, hawksbill, and Kemp's Ridley). The
endangered West Indian (or Florida) manatee inhabits waterways and bays along the
Florida peninsula. The anadromous Gulf sturgeon, recently designated as
threatened, has been found in waters of the Gulf and many of its tributary rivers.
In addition, a complex network of channels and wetlands within the Gulf shoreline
provides habitat for estuarine-dependent commercial and recreational fisheries.
The rich waters yielded approximately 771 million kg (1.7 billion pounds) of fish and
shellfish in 1991. Worth more than $641 million at dockside, this harvest
represented 19 percent of the total annual domestic harvest of commercial fish
(USDOC, 1992). The Gulf boasts the largest and most valuable shrimp fishery in the
U.S and also contributed 41 percent of the U.S. total oyster production in 1991
(USDOC, 1992). Other Gulf fisheries include diverse shellfisheries for crabs and
spiny lobsters and finfisheries for menhaden, herring, mackerel, tuna, grouper,
snapper, drum, and flounder. The entire U.S. Gulf of Mexico fishery yields more
finfish, shrimp, and shellfish annually than the South and Mid-Atlantic,
Chesapeake, and Great Lakes regions combined.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Ovarviow of the Gulf of Mexico
Chapter 1
The Gulf's bountiful waters draw millions of sport fishermen and beach users each
year. It is estimated that the Gulf supports more than one-third of the nation's
marine recreational fishing, hosting four million fishermen in 1985, who caught an
estimated 42 million fish (USDOC, 1992). Popular nearshore catches include sea
trout (weak fish), cobia, redfish, flounder, grouper, red snapper, mackerel, and
tarpon; offshore catches include blue marlin, white marlin, sailfish, swordfish,
dolphin, and wahoo. Tourism-related dollars in the Gulf Coast States contribute an
estimated $20 billion to the economy each year (USEPA, 1991).
Gulf oil and gas production are equally valuable to the region's economy and are a
critical part of the nation's total energy supply. In 1990, more than 1,600 Outer
Continental Shelf (OCS) leases were in production, yielding approximately 90
percent of U.S. offshore production. These OCS royalties annually contribute about
$3 billion to the Federal Treasury. Thirty-eight percent of all petroleum and 48
percent of all natural gas reserves in the U.S. are estimated to be in the Gulf of
Mexico. The industry employs some 30,000 people in the region.
Approximately 45 percent of U.S. shipping tonnage passes through Gulf ports,
including four of the nation's busiest: Corpus Christi, Houston/Galveston, Tampa,
and New Orleans. The second largest marine transport industry in the world is
located in the Gulf of Mexico. According to USEPA, vessel trips in and out of
American Gulf ports and harbors exceeded an estimated 600,000 trips in 1986. The
U.S. Navy is also implementing its Gulf Coast Homeporting Plan, designed to dock
at least 25 vessels in Ingelside, TX, Pascagoula, MS, and Mobile, AL.
Millions of people depend on the Gulf of Mexico to earn a living and flock to its
shores and waters for entertainment and relaxation. The temperate climate and
abundant resources are attracting more and more people. The region currently
ranks fourth in total population among the five U.S. coastal regions, accounting for
13 percent of the nation's total coastal population. Although the Gulf region is not
as densely settled as others, it is experiencing the second fastest rate of growth;
between 1970 and 1980, the population grew by more than 30 percent (USDOC,
1990a). According to the U.S. Department of Commerce, the Gulf's total coastal
population is projected to increase by 144 percent between 1960 and 2010, to almost
18 million people. Figure 1.1 shows the Gulf of Mexico coastal population density
or population per shoreline mile projected to the year 2010. Florida's population
alone is expected to have skyrocketed by more than 300 percent by the year 2010. The
increasing coastal population is of concern because as the population increases, so do
competing needs for freshwater.
The Gulfs resources and environmental quality are affected not only by the
millions living and working in the region, but also by activities occurring
throughout much of the nation. Over two-thirds of the land area of the contiguous
U.S. drains into the Gulf. Maintaining sufficient freshwater inflows into the Gulf is
vital to sustaining its vast and valuable resources.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter 1
Flgural.1
Gulf of Mexico Coastal Population per Shoreline Mile
(Source: USDOC, 1990a)
Gulf of Mexico Freshwater Inf lov/ Action Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter 1
The Gulf 'of Mexico - A Resource At Risk
Increasing populations result in increased use and demands on Gulf of Mexico
resources. Until recently, the Gulf was considered too vast to be affected by
pollution and overuse. However, recent trends indicate serious long-term
environmental damage unless action is initiated today. Potential problems or signs
of increasing degradation throughout the Gulf system include the following
(USEPA, 1991):
Q Fish kills and toxic "red tides" and "brown tides" were an increasing
phenomenon in Gulf waters during the 1980s.
Q Alabama, Mississippi, Louisiana, and Texas are among those states that
discharge the greatest amount of toxic chemicals into coastal waters.
Q More than half of the shellfish-producing areas along the Gulf Coast
are permanently or conditionally closed. These closure areas are
growing as a result of increasing human and domestic animal
populations along the Gulf Coast (USDOC, 1991b).
Q Diversions and consumptive use for human activities have resulted in
significant changes in the quantity and timing of freshwater inflows to
the Gulf of Mexico.
Q Louisiana is losing valuable coastal wetlands at the rate of
approximately 14-66 km2/year (5-25 mi2/year) (Dunbar, et al., 1992).
Q Almost 1,800 kg/mi (2 tons/mi) of marine trash covered Texas beaches
in 1988.
Q Up to 9,500 km2 (4,000 mi2) of oxygen deficient (hypoxia) bottom waters,
known as the "dead zone," have been documented off the Louisiana
and. Texas coasts (Rabalais, et al., 1991).
Q Gulf shorelines are eroding up to 30 m/year (100 ft/year). Few coastal
reaches in the Gulf can be characterized as "stable" or "accreting."
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter 1
The Gulf pf Mexico Program - Goals & Structure
Problems plaguing the Gulf cannot be addressed in a piecemeal fashion. These
problems and the resources needed to address them are too great. The Gulf of
Mexico Program (GMP) was formed to pioneer a broad, geographic focus in order to
address major environmental issues in the Gulf before the damage is irreversible or
too costly to correct.
The program is part of a cooperative effort with other agencies and organizations in
the five Gulf States, as well as with people and groups who use the Gulf. In addition
to the U.S. Environmental Protection Agency (USEPA), other participating federal
government agencies include: National Aeronautics and Space Administration
(NASA), U.S. Army Corps of Engineers (USAGE), U.S. Department of Agriculture
(USDA), U.S. Department of Commerce (USDOC), U.S. Department of Defense
(USDOD), U.S. Department of Energy (USDOE), U.S. Department of the Interior
(USDOI), U.S. Department of Transportation (USDOT), U.S. Food and Drug
Administration (USFDA), and Agency for Toxic Substances and Disease Registry
(ATSDR).
The Gulf of Mexico Program also works in coordination and cooperation with five
National Estuary Programs (NEPs) within the Gulf: Tampa Bay, Sarasota Bay,
Galveston Bay, Corpus Christi Bay, and the Barataria-Terrebonne Estuarine
Complex. The Gulf of Mexico Program supports and builds on certain activities of
these programs, bringing a Gulfwide focus and providing a forum for addressing
issues of Gulfwide concern.
By building on and enhancing programs already underway, as well as by
coordinating new activities, the Gulf of Mexico Program will serve as a catalyst for
change. The program's overall goals are to provide:
Q A mechanism for addressing complex problems that cross federal, state,
and international jurisdictional lines;
Q Better coordination among federal, state, and local programs, thus
increasing the effectiveness and efficiency of the long-term effort to
manage and protect Gulf resources;
Q A regional perspective to address research needs, which will result in
improved transfer of information and methods for supporting
effective management decisions; and
Q A forum for affected groups using the Gulf, for public and private
educational institutions, and for the general public to participate in the
solution process.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter I
The Gulf of Mexico Program is supported by four committees: Policy Review Board
(PRB), Management Committee (MC), Citizens Advisory Committee (CAC), and
Technical Advisory Committee (TAG) (see Figure 1.2). Composed of 20 senior level
representatives of state and federal agencies and representatives of the technical and
citizens committees, the Policy Review Board guides and reviews overall program
activities. The Management Committee guides and manages Gulf of Mexico
Program operations and directs the Action Agenda activities of the Issue
Committees. The Citizens Advisory Committee is composed of five governor-
appointed citizens who represent environmental, fisheries, agricultural,
business/industrial, and development/tourism interests in each of the five Gulf
Coast States. This committee provides public input and assistance in publicizing the
Gulf of Mexico Program's goals and results. Representatives of state and federal
agencies, the academic community, and the private and public sectors are members
of the Technical Advisory Committee and provide technical support to the
Management Committee.
The Gulf of Mexico Program has established the following eight Issue Committees,
each co-chaired by one federal and one state representative, to address priority
environmental problems:
Q Habitat Degradation of such areas as coastal wetlands, seagrass beds,
and sand dunes;
Q Freshwater Inflow changes resulting from reservoir construction,
diversions for municipal, industrial, and agricultural purposes, and
modifications to watersheds with concomitant alteration of runoff
patterns;
Q Nutrient Enrichment resulting from such sources as stprm water,
industries, and agriculture;
Q Toxic Substances & Pesticides contamination originating from
industrial and agriculturally based sources;
Q Coastal & Shoreline Erosion caused by natural and human-related
activities; , .
D Public Health threats from swimming in and eating seafood products
coming from contaminated water;
Q Marine Debris from land-based and marine recreational and
commercial sources; and
Q Living Aquatic Resources.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter i
Flgur«1.2
Gulf Program Structured Partnership
__ 1
Policy Rev
L__
(Cltlzvru Advisory 1
Commit!** m
•' I
(Co-Ctulr R*vl*w ]
Council J
r
ew Board 1
[^^^••••aB^^r
(ToehnlcMil Advlcary |
Commllt** H
> .
Ucu* CornmHt»»» 1
Habitat Degradation
Public Health
Freshwater Inflow
Marine Debris
Coastal & Shoreline Erosion
Nutrient Enrichment
Toxic Substances &
Pesticides
LMng Aquatic Resources
Program Operations Support
Cuff of Mexico
Program Office
Public Education & ,
Outreach Operations
Dana & Information
Transfer Operations
• T ' ' ' ^M^^^^
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Ovorvlow of the Gulf of Mexico
Chapter 1
Two cross-cutting technical operating committees support the public education and
information and resource management functions of the eight environmental Issxie
Committees. These are:
Q Public Education & Outreach Operations
Q Data & Information Transfer Operations
The action planning process used by each Gulf of Mexico Program Issue Committee
includes the following key activities:
Q Definition of environmental issues;
Q Characterization of identified problems, including sources, resources,
and impacts;
Q Establishment of goals and objectives;
Q Evaluation/assessment of corrective actions and control measures,
including cost/benefit analysis;
Q Selection of priority action items;
Q Establishment of measures of success;
Q Implementation of actions; and
Q Evaluation of success and revision of the Action Agenda.
As the Issue Committees progress through each of these activities, ample
opportunities are provided for public review and Policy Review Board endorsement
is requested at appropriate points. The Gulf of Mexico Program will continuously
work to integrate related activities of the eight Issue Committees. Through the
consensus of Program participants, a coordinated response will be directed to the
successful maintenance and enhancement of resources of the Gulf of Mexico.
Gulf of Mexico Freshwater Inflow Aetlon Agenda (3.1)
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Overview of the Gulf of Mexico
Chapter i
The Freshwater Inflow Committee
The Co-Chairs and membership of the Freshwater Inflow Committee are as follows:
Co-Chairs;
Susan Rees
Bruce Moulton
Members:
Len Bahr
Joan Browder
Fred Deegen
Dick Eckenrod.
Ernie Estevez
David Hankla
Dave Smith
John Klein
Larry Land
Fritzi Pikes
Don Waller
Janet Starnes
Walter Stevenson, Jr.
Lon Strong
John Weber
U.S. Army Corps of Engineers
Texas Natural Resource Conservation Commission
Louisiana Office of the Governor
National Marine Fisheries Service
Mississippi Bureau of Marine Resources
Tampa Bay National Estuary Program
Mote Marine Laboratory
U.S. Fish & Wildlife Service ' ,.
U.S. Fish & Wildlife Service/Gulf of Mexico Program... " "
National Oceanic & Atmospheric Administration
U.S. Geological Survey , „ : .,.,,,,.
Texas Natural Resource Conservation Commission--CAC.
Mississippi Farm Bureau Federation~CAC
Northwest Florida Water Management District
Alabama Department of Economic & Community Affairs
U.S. Soil Conservation Service
U.S. Army Corps of Engineers
The Freshwater Inflow Committee developed the following goal for addressing
freshwater inflow issues in the Gulf of Mexico:
Q Protect, preserve, restore, and, where feasible, enhance the freshwater
inflow to the Gulf of Mexico and the associated bays and estuaries for
the purpose of maintaining the ecological health and integrity of those
systems.
For the purposes of this Action Agenda, "freshwater" includes surface water, ground
water, springs, and precipitation.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
9
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Overview of the Gulf of Mexico
Chapter 1
The Gulf of Mexico Policy Review Board endorsed this goal on November 8,1990.
In developing this Draft Action Agenda, the Freshwater Inflow Committee has
sought input and advice from the other Issue Committees, as well as from
organizations, interest groups, and private concerns outside of the Gulf of Mexico
Program. An "Action Agenda Workshop" sponsored by the Issue Committee in
New Orleans, LA, on April 15-16,1993, to review an early version of the Action
Agenda, was attended by approximately 40 persons comprising a mix of Program
and non-Program participants. In addition to Gulf of Mexico Program participants,
representatives from the following agencies and organizations attended the
workshop: Lake Pontchartrain Basin Foundation, Trinity River Authority, Florida
Department of Community Affairs, Southwest Florida Water Management District,
U.S. Fish & Wildlife Service, Manatee County Public Works Department,
Mississippi Farm Bureau Federation, Northwest Florida Water Management
District, Louisiana State University, Texas Parks & Wildlife Department, Lower
Colorado River Authority, U.S. Geological Survey, Mississippi State University,
Mississippi Water Resources Research Institute, Texas Water Development Board,
County Sanitation Districts of Orange County (California), Galveston Bay National
Estuary Program, University of South Alabama, and University of Florida. This
meeting generated a significant number of action items and comments that were
addressed in the present document. (See Appendix D: Participants in the Action
Agenda Development Process.)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
1O
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
2 FRESHWATER INFLOW IN THE GULF OF MEXICO
Role of Freshwater Inflows In Estuarine Ecosystems
Estuaries are by definition bodies of water that receive freshwater inflows. Estuaries
function as transition zones between the freshwater of a river and the saline
environment of the sea. The estuaries of the Gulf of Mexico are highly productive
ecosystems that support wildlife and fisheries and contribute substantially to the
economy of coastal areas. Estuarine-dependent species comprise more that 95
percent of the commercial fishery harvests from the Gulf of Mexico, and many
important recreational fishery species also depend on estuaries during some part of
their life cycle. The ability of an estuary to function as a nursery depends upon the
quantity, timing, and input-location of freshwater inflows. Estuarine ecosystems are
very vulnerable to disturbances by humans, primarily upstream withdrawals of
water for agricultural, industrial, and domestic purposes; contamination by
industrial and sewage discharges and agricultural runoff carrying pesticides and
herbicides; and eutrophication caused by excessive nutrient inputs from a variety of
nonpoint (agricultural drainage, faulty septic systems) and point sources (sewage
treatment plants) (Rozengurt and Haydock, 1991).
Freshwater inflows provide the following important functions within an estuary:
Q Provide a food supply by stimulating both photosynthesis and
microbial decomposition;
Q Deposit sediments that stabilize coastal wetlands against erosion,
subsidence, and sea level rise;
Q Drive estuarine circulation by establishing salinity gradients; and
Q Create a range of salinities under which plants and animals with
various salinity needs can thrive.
Diversions of freshwater inflows from estuarine ecosystems is one of the four
highest priority threats to living marine resources nationwide (Chambers, 1991).
The future of fisheries and wildlife in the Gulf depends upon recognizing and
preventing the estuarine habitat degradation caused by freshwater inflow
alterations.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
11
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
As a result of the National Symposium on Freshwater Inflow to Estuaries (1980), the
Texas Department of Water Resources reviewed its studies on six estuaries and
observed that a 32 percent depletion of natural freshwater inflow to estuaries was
the average maximum percentage that could be permitted if subsistence levels of
nutrient transport, habitat maintenance, and salinity control were to be maintained
(Clark and Benson, 1981).
Gulf of Mexico Freshwater Inflow Aeilon Agenda (3.1)
12
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
Salinity Characteristics of Gulf of Mexico Estuaries
Salinity is an important environmental factor affected by alterations in freshwater
inflow. A change to the salinity structure of an estuary may cause impacts
throughout the system, at scales many times larger than the impacts of wetland loss
or pollutant discharge. To a great extent, distributions of organisms in an estuary
are determined by salinity, which in turn is determined by a complex suite of
interacting factors including rainfall, river discharge, tides, wind, and basin
configuration. Human alteration of river flow can significantly affect the salinity
regime of an estuary, and thereby change its biota.
Salinity is a fundamental environmental factor because all organisms are 80 to 90
percent water, and internal salt concentrations must be maintained within a certain
range in each species. Each species or life stage within a species is adapted to a
particular external environment. Most estuarine organisms can tolerate a wider
range of external salinities than oceanic species; however, even estuarine species
have tolerance limits. Few estuarine species can function optimally within the
entire salinity range from fresh to sea water. Most organisms are associated with
either the higher end of the salinity range (25-36 ppt) or the middle range (10-25 ppt),
but not both. Few estuarine organisms will tolerate salinity fluctuations greater
than 15 or 20 ppt.
The range of salinity tolerance changes over an organism's lifetime. The typical
pattern for an estuarine-dependent species is to spawn offshore in waters at, or near,
seawater strength. Post larvae then move into an estuary and settle at the lowest
optimal salinity. As it grows, the organism gradually moves into higher salinity
water. Finally, as a late juvenile or early adult, the organism migrates offshore.
Outside the optimal salinity range, a reduction in reproduction, growth, and
survival is expected, even if the species is still present in that range.
Shifts in salinity distributions caused by changes in freshwater inflows can shut
species out of formerly ideal refuges, feeding areas, and nursery grounds.
Alterations in freshwater inflow can dramatically change the distribution of
salinities across an estuary. For example, changes in freshwater inflow can shift the
boundary between fresh and salt water (usually considered the one part per
thousand isohaline) several miles up or down stream. The result may be a drastic
area reduction of bottom types that are suitable for a given species. Although many
organisms are mobile, movement does not benefit them if no suitable areas with
favorable salinities are available or if such areas have become so small'that
crowding occurs. Because of the effect on salinity patterns alone, changes in
freshwater inflow can reduce the overall carrying capacity of an estuary.
Because horizontal salinity gradients serve as physiological barriers for some
organisms, salinity effectively screens potential predators from estuarine organisms
tolerant of low and fluctuating salinities (Snedaker et al., 1977). Human induced
increases in estuarine salinities may eliminate this barrier and cause a change in
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Froshwator Inflow in the Gulf of Mexico
Chapter 2
resident species populations (Northwest Florida Water Management District, 1991).
Increasing salinization of estuarine ecosystems also leads to saltwater intrusion and
eventual destruction of natural seasonal gradients (Rozengurt and Haydock, 1991).
Freshwater river plumes discharging into the northern Gulf of Mexico reduce
salinities of nearshore Gulf waters, especially in May and October (Cochrane and
Kelly, 1986). These low-salinity waters generally drift westward, driven by
southeasterly winds and the pressure gradients. The degree in which salinities in
Texas estuaries are affected by these low-salinity waters depends on their proximity
to major river plumes and to the year-to-year variability in river discharges,
especially those of the Atchafalaya and Mississippi Rivers (Orlando, et al., 1993).
These plumes are also responsible for the high variability in shelf salinity off the
Texas coast, compared to those off the Florida coast (Orlando, et al., 1993).
NOAA's National Estuarine Inventory (Orlando, et al., 1993) examined the salinity
structure and variability of 26 Gulf of Mexico estuaries. (Figure 2.1 provides a map
illustrating the location of the estuaries discussed.) To the extent that data allowed,
the salinity structure was represented by typical seasonal distributions existing under
normal and present-day hydrologic conditions. This structure: 1) indicates the
relative influence of seawater and freshwater sources in the estuary; 2) provides a
common basis for comparisons between estuaries; and 3) becomes a reference point
for salinity variability analysis. The following characterization uses temporal
variability to differentiate functional differences between five estuary types having
direct influence on resource distribution and water quality.
Variability Across the Region. The geographical proximity of Gulf estuaries
suggests a certain degree of similarity in such features as morphology,
hydroclimatology, and salinity structure. In general, five broad gepgraphic
groupings are recognizable. The extremes, represented by the shallow, arid, high
salinity systems of the Florida peninsula and south Texas, sharply contrast with the
broad, water-rich, low salinity embayments of the Mississippi and Atchafalaya River
deltas. Intermediate conditions exist from the Florida panhandle to the Mississippi
Sound and from western Louisiana to the Texas coastal bend. The former are
relatively deep, receive moderate-to-high freshwater inflows, and have
intermediate salinity concentrations, while the latter are typically shallow
embayments that receive low-to-moderate freshwater volumes and have
correspondingly higher salinities (Orlando, et al., 1993).
While the geographic groups reflect Gulf of Mexico estuaries with certain common
characteristics, important functional differences exist among many adjacent systems,
due to variation in other controlling factors such as Gulf wind and bathymetric
influences. The dynamic balance of these factors can be determined by
characterizing estuarine salinity (Orlando et al., 1993). Figure 2.2 and Table 2.1
arrange the Gulf systems by combinations of salinity variability, expressed at weekly
and seasonal time scales.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
14
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
Figure 2.1
Gulf of Mexico Estuaries
Eastern Gulf of Mexico
Central Gulf of Mexico
Western Gulf of Mexico
1
2
3
4'
5
I 6
| 7
Sarasota Bay n
Tampa Bay
Suwannee River
1 —
Apalachee Bay 1 "
Fstuarie?
r
Apalachicola Bay r.
St. Andrew Bay "~
Choctawhatchee
1_| Mississippi Sound
2 Lakes Pontchartrain/
Borgne & cnandeieur
Sound
1
3 I Breton Sound
1
4 I Barataria Bay
1
5 | Terrebonneflimbalier
Bays
6 I Atchafalaya/
19
20
21
17
23
24
25
Sabine Lake
Galveston Bay
Brazos/San Bernard
Rivers & Cedar Lakes
Matagorda Bay
San Antonio Bay
Aransas Bay
Corpus Christ! Bay
Bay
8 I Pensacola Bay
Perdido Bay
Mobile Bay
10
Vermilion Bays
117 I Mermentau River
18 Calcasieu Lake
26 I Laguna Madre
(Source: Orlando eta/., 1993).
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Figure 2.2
Estuary Types Based on Infra-Annual Salinity
Variability
R 3 8
8 55 8
I*. IA «A 40 40
CM n n
U) U)
-------
Freshwater Inflow In the Gulf of Mexico
Chapter 2
Table 2.1
Estuary Types Based on Infra-Annual Salinity
Variability
Tyi**;
i
2
3
4
S
Magnitude of Variability
Weekly* $em*enmi
L
M
M
L
L
L
L
M
M
L
Average Annual
Salinity
High
(Seawater-
domlnated)
Intermediate
Intermediate
Intermediate
Low
(Freshwater-
dominated)
*L - lew; M- medium
(Source: Orlando et al., 1993).
This categorization is based on average annual salinity and its intra-annual
variability under normal hydrologic conditions. Some estuaries may be
inappropriately categorized due to the lack of data (e.g., Suwannee River, Mississippi
Sound, and Mermentau River) (Orlando et al., 1993).
The resulting five estuarine types include a sampling of systems from around the
Gulf with different morphological features. Despite this, estuaries within each type
share a common relationship to salinity variability, mean estuarine salinities, and
freshwater inflow. While seemingly discrete, the five estuary types actually lie
along a continuum with considerable overlap between types 2 through 4 (Orlando et
al, 1993).
Types 1 and 5. These types are stable. They represent the extreme range of freshwater
inflow to Gulf estuaries and, correspondingly, the extreme range of salinity
behavior. At these extremes, a single mechanism dictates the salinity (in this case,
average annual salinities) and precludes any significant intra-annual variability. In
type 1 estuaries, which lack a dominant and continuous freshwater source, salinity
is predominately near (or above) Gulf values and quite stable. In contrast, type 5
salinities are overwhelmed by a dominant and continuous freshwater inflow
source. Even when variable, inflow is still so great that there is little salinity
intrusion and, therefore, low variability. Consequently, low variability may be
realized through either of two opposing scenarios: sea water dominance or
freshwater dominance (Orlando et al., 1993).
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Types 2 through 4. These three estuary types are variable. They reflect intermediate
freshwater inflow conditions, intermediate mean salinities, and a shift in both the
magnitude and dominant time scale of salinity variability. In these systems, the
salinity structure and variability are not determined solely by freshwater inflow, but
also depend on the relative influence of other physical factors such as tidal
exchange. Freshwater inflow generally increases and becomes more continuous
from type 2 to type 4, progressively suppressing seawater intrusions and shifting the
dominant time scale of salinity variability from weekly to seasonal. The magnitude
of salinity variability, however, achieves a maximum at type 3 (i.e., these systems
experience medium variability at both the weekly and seasonal time scales), as
neither seawater nor freshwater sources predominate. Because the range of inflow
defining each of these intermediate types is somewhat overlapping, a given estuary
can transition between types (Orlando et al., 1993).
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Other Factors Affected by Freshwater Inflow
Changes in nutrient and sediment loads associated with altered freshwater inflow
can also disrupt the nursery function of an estuary by affecting food and habitat
availability. Various studies have shown that changes in phytoplankton,
zooplankton, and benthos, as well as fish and invertebrates, are associated with
alterations in freshwater inflow. Freshwater inflow changes can affect such water
quality parameters as suspended sediments, dissolved oxygen (DO), water
temperature, and pH, which in turn affect biota.
Suspended sediments are usually deposited in estuaries, as the flow velocity of the
river widens and slows. This natural process helps offset settling of deposited soils,
erosion, and other processes removing solids. Suspended sediments are also
commonly associated with nutrients. Some materials such as particles of decaying
organic matter are obvious nutrient sources. Phosphorous is also commonly carried
in soil sediments, as can be pesticides of various types. In the water column,
sediments absorb sunlight, decreasing the level of light penetration. This causes
stratified heating of the upper levels of water and inhibits the growth of benthic
plants. Sediments can also carry bacterial populations.
The DO level in water is one of the primary factors determining the populations
which can survive in those waters. Some of the most preferred game species
require relatively high DO levels (more than 5 ppm), while some species (catfish)
survive well at 2 ppm. As DO drops from 2 ppm to 0 ppm, the number of species
surviving tends to shift rapidly to favor anaerobic bacterial populations. The
primary cause of DO depletion is metabolism of nutrient loads, mostly by bacteria.
The potential for this type of oxygen consumption is commonly measured as
Biochemical Oxygen Demand (BOD). The primary sources of DO are surface mixing
and photosynthesis of phytoplankton populations.
Water temperature determines not only which species are present in a population,
but also much of the timing of their life cycles. Species demanding high DO are
commonly associated with lower water temperatures since low temperatures allow
more oxygen to be dissolved. The metabolic rate of most aquatic species is directly
determined by the water temperature in a relationship where a change in water
temperature of 10° C causes a doubling of the metabolic rate. Thus, higher water
temperatures stimulate rapid growth, but can reduce the DO available to support it.
Water pH in the range of five to nine is usually regarded as acceptable for most
species, with a pH around eight being preferred. Outside this range, pH becomes
first a stress, then lethal. In natural waters, a low pH is commonly associated with
outflow from watersheds rich in digestible carbon, such as forests and bogs. These
produce tannic acids, as well as the carbonic acid formed by metabolism. High pH
can be associated with high phytoplankton loads in poorly buffered waters, with pH
rising as carbonic acid is removed through photosynthesis. The primary resistance
to pH fluctuations in natural waters is the carbonate buffering system. Waters rich
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
19
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
in carbonates and bicarbonates require massive additions of acid or alkaline to
produce even modest changes in pH.
Freshwater inflow is also important for the process of circulation and flushing in
estuaries. In some estuaries, such as Tampa Bay, horizontal density gradients
established by freshwater inflows combine with winds and tides to drive circulation
in the estuary. The resulting currents and related flushing rates not only influence
water quality, but are also instrumental in transporting planktonic organisms
throughout the estuary. Freshwater inflows also flush planktonic organisms and
detritus into the Gulf of Mexico, providing food for those organisms that do not
enter the estuaries.
The estuarine sediments of many river deltas slowly consolidate. Reduced
freshwater inflow will invariably reduce or even eliminate significant sediment
inflow. If sediment inflow is eliminated from such estuaries, wetland loss due to
consolidative subsidence and erosion accelerates. This is particularly true of deltaic
regions of the Louisiana Gulf coast.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
20
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Quantity of Freshwater Inflows to the Gulf of Mexlee
The Gulf of Mexico watershed represents over two-thirds of the drainage of the
contiguous U.S. into the coastal ocean. This watershed is subject to nearly the full
range of North American climates, corresponding to a wide range of inflows to its
estuaries. Figure 2.3 shows the inflow variation with distance around the. Gulf coast
(Orlando, et al., 1993). This inflow is roughly symmetrical, centered on the
Mississippi River Delta, with a range of over two orders of magnitude, from the arid
segments of the Florida and Texas coasts to the water-rich Mississippi delta. [Figure
2.3 depicts the general variation of the Gulf's river flow but should not be used to
infer that the inflow is a smooth function of coastline position. River flow is
concentrated in the principal drainage ways and would appear as spikes of inflow,
separated by large distances with no inflow. Figure 2.3 greatly smooths this
variation by averaging over 250 km (155 mi) segments.]
The timing of freshwater delivery to Gulf of Mexico estuaries ranges from seasonal
dominance in the central Gulf to isolated, short-duration, high intensity pulses in
Florida and Texas (Orlando, et al., 1993). The timing and fluctuation of river flow
are further modified by reservoirs located on most major rivers flowing to Gulf
estuaries (Orlando, et al., 1993). The relationship of freshwater inflows to salinity
distributions, habitat, water circulation patterns, and pollutant transport is
dependent on both the volume and timing of delivery, as well as interaction with
other physical forcing mechanisms. The influence of freshwater inflows varies
between estuaries and within any given estuary.
The volume of instream flows is important not only to the receiving estuaries, but
also to the rivers and streams that carry these flows. High flowing rivers and
streams support more productivity on their river-sides and banks. In addition, high
flowing rivers capture and transport more organic material and detritus from the
productive river-side areas to estuaries for nourishment. The flushing of the
cypress swamps and bottomland hardwood areas of the Wallisville Area on the
Trinity River Delta to Trinity Bay is a good example of this.
The U.S. Geological Survey (USGS) reports on inflows provide data on inflows to
rivers, not necessarily to estuaries. USGS reports investigate impoundment effects
for selected rivers, but these results should not be applied to the unstudied ones,
which may be smaller and more prone to local impoundment/diversion effects.
Almost all of the data concerning the quantity and water quality of streamflow to
the Gulf of Mexico are being collected by USGS and are available from computer
storage.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
21
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
FI0ur* 2.3
General Variation of River Flow Around the Gulf
Florida
Paninsula
500 1,000 1.500 2.000
Portico on CoMtHM (tan from FUo Grand*)
£600
(Source: Orlando, et al., 1993)
Quantity and Water Quality of Streamflow to the Gulf. Long-term continuous
streamflow records exist for almost all major streams that discharge directly to the
Gulf of Mexico. Fifty-four streams, each with drainage areas greater than 518 km2
(200 mi2), that discharge directly to the Gulf of Mexico or its estuaries have been
identified and classified as major streams ( see Table 2.2). The total drainage area for
these streams, almost 4.693 million km2 (1.812 million mi2), represents about 95
percent of the total drainage area to the Gulf (not including the contribution from
Mexico). A compilation of drainage areas to the Gulf of Mexico and drainage areas
gaged for streamflow is presented in Table 2.3; selected characteristics for data
available from streamflow gages proximate to the Gulf of Mexico are presented by
state in Table 2.4 (USGS, 1992).
Daily values for dissolved solids are available at gages on 44 of the major streams
and all but one of the major streams with drainage areas greater than 2,590 km2
(1,000 mi2) (see Table 2.2). The total drainage area of these gages is about 4.7 million
km2 (1.8 million mi2). Selected characteristics of the dissolved-solids data base for
streamflow gages within 320 km (200 mi) of the Gulf of Mexico are presented in
Table 2.4.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
22
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Tabl« 2.2 Periods of Record for U.S. Geological Survey Dally Values
of Water Quality & Streamflow for the Lower Reach of
Major Streams That Discharge Directly to the Gulf of
Mexico & Its Estuaries
I STREAM NAME (STATE)
1
1
RIO GRANDE (TX)
SAN FERNANDO CREEK (TX)
NUECES RIVER (TX)
ARANSAS RIVER (TX)
MISSION RIVER (TX)
SAN ANTONIO RIVER (TX)
GUAOALUPE RIVER (TX)
LAVACA RIVER (TX)
COLORADO RIVER (TX)
SAN BERNARD RIVER (TX)
BRAZOS RIVER (TX)
BUFFALO BAYOU (TX)
TRINITY RIVER (TX)
PINE ISLAND BAYOU (TX)
VILLAGE CREEK (TX)
NECHES RIVER (TX)
SABINE RIVER (TX)
CALCASIEU RIVER (LA)
BAYOU NEZPIQUE (LA)
VERMILION RIVER (LA)
ATCHAFALAYA RIVER (LA)
MISSISSIPPI RIVER (LA) 1
AMITE RIVER (LA)
TANGIPAHOA RIVER (LA)
BOGUE CHITTO (LA)
PEARL RIVER (MS)
WOLF RIVER (MS)
RED CREEK (MS)
BLACK CREEK (MS)
PASCAGOULA RIVER (MS)
TOHBIGBEE RIVER (AL)
ALABAMA RIVER (AL)
PERDIOO RIVER (AL)
ESCAHBIA RIVER (FL)
BIG COLOWATER (FL)
BLACKWATER RIVER (FL)
YELLOW RIVER (FL)
SHOAL RIVER (FL)
CHOCTAWHATCHEE RIVER (FL)
CHIPOLA RIVER (FL)
APALACHICOLA RIVER (FL)
OCHLOCKONEE RIVER (FL)
SAINT MARKS RIVER (FL)
AUCILLA RIVER (FL)
STEINHATCHEE RIVER (FL)
SUUANNEE RIVER (FL)
WACCASASSA RIVER (FL)
WITHLACOOCHEE RIVER (FL)
HILLSBOROUGH RIVER (FL)
ALAFIA RIVER (FL)
HYAKKA RIVER (FL)
HORSE CREEK (FL)
PEACE RIVER (FL)
1 DRAINAGE | PERIOD OF RECORD AND NUMBER OF YEARS OF DATA FOR:
1 AREA I STREAMFLOW I DISSOLVED i SEDIMENT
I (HI ) | 1 SOLIDS 1
335.500 11934-88 (55) 11966-88 (19) 11966-83 (18)
507 11965-88 (24) | 1 —
16.660 11940-88 (49) 11942-88 (47) 11950-51 ( 2)
247 11965-88 (24) 1 — 1 —
690 11940-88 (49) 11962-81 (20) -1
3.921 11925-88 (53) (1960-88 (29) 1
5.198 11936-88 (53) 11966-83 (18) 1
817 11939-88 (50) 11978-81 ( 4) I
42.240 11939-88 (SO) 11945-88 (44) 11957-73 (17)
727 11955-88 (34) 11978-81 (4) 1
45.007 11904-88 (68) 11942-88 (47) 11966-86 (21)
317 11964-88 (17) 11979-88 ( 6) 1
17.186 11925-88 (64) 11942-88 (43) 11955-71 ( 4)
336 11968-88 (21) 11968-81 (14) I
860 11925-88 (51) 11968-70 ( 3) 1
7.951 11905-88 (69) 11948-88 (41) 1
9.329 11925-88 (64) 11946-88 (42) I
1.700 11923-88 (52) 11968-87 (12) I
527 11939-88 (50) I 1 —
UNKNOWN 11968-88 (21) 11958-82 (20) 1
87.570 11935-88 (54) 11952-81 (16) 11973-85 ( 9)
.129.810 11934-88 (55) 11950-88 (39) 11950-75 (26)
1.280 11939-88 (50) 11968-81 (12) I
646 11939-88 (50) 11963-83 ( 6) 1
1.213 11938-88 (51) 11975-82 ( 8) 1
6.573 11939-88 (SO) 11963-85 (13) 11967-87 (21)
308 11972-88 (17) 11978-81 ( 4) I —
441 11959-88 (30) 11985-86 ( 2) 1
701 11972-68 (17) 1 — 1 —
6.590 11931-88 (58) 11970-81 (12) I
18.417 11929-88 (60) 11966-88 (21) 1
22.000 11931-88 (58) 11966-87 (17) 1
394 11942-88 (47) 11979-81 ( 3) 1
3.817 11935-88 (54) I — 1
237 11938-88 (49) 1 1 -
205 11951-88 (38) 1 - 1 -
624 11939-88 (50) 11965-72 ( 8) 1
474 11939-88 (SO) 1 1
4.384 11930-88 (59) 11964-83 (18) 1
781 11922-88 (53) 11965-72 ( 8) 1
17.200 11929-88 (60) 11963-79 (17) 1
1.700 11927-88 (62) 11965-72 ( 8) I
535 11957-88 (30) 1 — 1 —
747 11950-88 (39) 11979-81 ( 3) 1
350 11951-88 (38) 11979-82 ( 4) I
9.640 11942-88 (47) 11966-77 (12) 1
480 11964-88 (18) 1 — 1 —
2.020 11970-88 (19) 11950-83 (23) I
650 11939-88 (50) 11965-82 (11) 1
335 11933-88 (56) 11958-86 (22) I
229 11937-88 (52) 11963-81 ( 6) 1
218 11951-88 (38) 11965-67 ( 3) 1
1.367 11932-88 (57) 11962-81 (20) 1
CALOOSAHATCHEE RIVER (FL) UNKNOWN 11967-88 (22) 11965-82 (17) I
DISSOLVED
OXYGEN
—
—
~
—
—
—
—
—
—
—
—
986-88 ( 3)
975-88 (14)
—
—
--
968-75 ( 8)
968-77 ( 5)
—
971-82 (12)
—
1967-88 (22)
—
~
1975-85 (11)
—
—
—
~
—
—
—
—
—
—
~
—
—
—
pH 1 WATER
I TEMPERATURE
11967-83 (11)
|
(1948-88 (33)
|
11961-81 (21)
11959-88 (30)
11967-83 (17)
11978-81 ( 4)
11948-88 (36)
11978-81 < 4)
11951-88 (35)
11979-88 ( 6)
1975-88 (14) 11950-88 (35)
11968-88 (21)
11968-70 ( 3)
11948-88 (30)
1968-75 ( 8) 11948-88 (34)
1968-77 ( 5) 11968-87 (12)
1
1976-82 ( 7) 11949-82 (25)
11953-84 (12)
1968-88 (21) 11954-88 (33)
11968-81 (11)
11963-83 ( 6)
11975-82 ( 8)
1975-85 (11) 11963-85 (13)
11978-81 ( 4)
11985-86 ( 2)
|
11958-81 (13)
11963-88 (26)
11966-87 (17)
11979-81 ( 3)
— . |
11960-60 ( 1)
11961-69 ( 3)
11965-72 ( 8)
|
11965-83 (17)
11965-72 ( 8)
1974-79 ( 6) 11974-78 ( 5) 11965-79 (14)
11965-72 ( 8) 11965-72 ( 8)
- 1 - 1
| — 11979-81 ( 3)
| — (1979-82 ( 4)
| - 11965-77 (13)
1 — 1
11950-50 ( 1) 11950-83 (21)
1 — 11965-82 (11)
11964-70 ( 5) 11958-86 (21)
1 — 11963-81 ( 7)
| - 11965-67 ( 3)
11962-70 ( 7) 11962-81 (20)
| — 11964-83 (20)
Notes:
Daily-values data not collected where dashed.
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
23
-------
Froshwator Inflow in the Gulf of Mexico
Chapter 2
Table 2.3 Drainage Areas & Gaged Drainage Areas to the Gulf of
Mexico
AREA DESCRIPTION
SQUARE
MILES
1. Area of the 48 contiguous States 3,022,260
2. Drainage area to the Gulf along United States boundaries,
including the Rio Grande 1,901,499
3. Drainage area to the Gulf from the Rio Grande 335,500
4. Drainage area to the Rio Grande from the United States 133,000
5. Drainage area to the Rio Grande from Mexico 202,500
6. Drainage area for title 54 identified major streams that discharge to
the Gulf 1,811,656
7. Drainage area for the 44 identified long-term streamflow-gaging
stations 1,804,151
DRAINAGE AREAS BY STATES (SQUARE MILES)
AND PERCENTAGES OF TOTAL DRAINAGE
State
Texas
Louisiana
Mississippi
Alabama
Florida
TOTALS
Total Drainage
to Gulf Along
State's Border
518,650
1,250,249
20,830
44,650
67..120
1,901,499
Drainage for
Identified
Major Streams
487,493 (97%)
1,222,746 (98%)
14,613 (70%)
40,811 (91%)
45,993 (69%)
1,811,656 (95%)
Drainage for
Identified Long-Term
Streamflow Gage
485,540 (94%)
1,222,973 (98%)
13,163 (63%)
40,811 (91%)
41,664 (62%)
1,804,151 (95%)
Note: Three rivers join the Gulf along boundaries between the above states. For purposes
of this study, the Sabine River is assumed to be in Texas, the Pearl River in Mississippi, and
the Perdido River in Alabama.
Drainage areas for stream gages are taken from U.S. Geological Survey computer files for
individual gages. Other drainage areas used throughout this report are aggregated from a
computer file of hydrologic unit codes, descriptions, names, and drainage areas maintained
by the U.S. Geological Survey. The file is published in:
Seaber, P.R, Kapinos, P.P., and Knapp, G.L., 1987, Hydrologic Unit Maps: U.S.
Geological Survey Water Supply Paper 2294, 63 p.
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
24
-------
Fr&shwater Inflow in the Gulf of Mexico
Chapter 2
Table 2.4 Selected Characteristics of the U.S. Geological Survey
Data Base for Dally Values of Streamflow & Dissolved
Solids for Stream Gages Within 2OO Miles of the Gulf of
Mexico
State
Texas
Louisiana
Mississippi
Alabama
Florida
Texas
Louisiana
Mississippi
Alabama
Florida
Gaged
Constituent
Streamflow
Streamflow
Streamflow
Streamflow
Streamflow
Dis. Solids
Dis. Solids
Dis. Solids
Dis. Solids
Dis. Solids
Number
of Sites
395
205
93
284
219
77
68
30
70
60
Mean Value for
Years
of Data
24
19
24
15
17
15
9
4
5
9
Beginning
Year
1956
1957
1950
1955
1964
1968
1969
1975
1977
1969
Ending
Year
1981
1979
1975
1973
1982
1982
1977
1978
1982
1977
Maximum
Years of
Record
92
59
69
70
67
46
56
15
33
33
Minimum
Years of
Record
1
1
1
1
1
1
1
1
1
1
Note: Within about 200 miles of the Gulf, daily values of streamflow exist for 11 96 gages and
daily values for salinity of streamflow exist for 305 gages within the U.S. Geological Survey
data base. Gages for the quantity and quality of streamflow are numbered in downstream
order by the U.S. Geological Survey. The gage numbers included in this summary, by states,
are as follows:
State Range of gage numbers
Texas 08020000-08042500; 08064000-08078000; 08096500-081 18000;
081 50000-0821 2000; and 08451 000-085555555
Louisiana All gages
Mississippi 02441000-02999999; 07285500-07999999
Alabama 02000000-02999999
Florida 02291 000-0231 0290; 0231 0900-0231 3265; 0231 3700-02370000
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
25
-------
Froshwator Inflow in the Gulf of Mexico
Chapter 2
Daily values for water temperature are available for most of the major streams
(Table 2.2), while daily values for suspended sediment, dissolved oxygen, and pH
are available for only some of the major streams. Periodic values for nutrients,
physical organics and inorganics, indicator bacteria, inorganic-chemical constituents,
minor elements, insecticides, and herbicides are available at many streamflow gages
within 320 km (200 mi) of the Gulf of Mexico. These data are collected infrequently,
commonly about four to eight samples per year, and thus would be difficult to use
in quantitative analyses concerning water-quality loads or trends without the use of
advanced statistical models.
Historical Streamflow to the Gulf. Almost every identified major stream that
discharges directly to the Gulf of Mexico has been gaged for streamflow discharges by
the U.S. Geological Survey. Selected characteristics for the long-term streamflow
gages are presented in Table 2.5, and annual mean streamflow discharges from 1947
to 1986 are presented in Tables 2.6,2.7, and 2.8 (USGS, 1992).
Temporal Variation. The monthly and seasonal cumulative variation in freshwater
inflows produces the most dramatic changes in bay-wide salinities in most Gulf of
Mexico estuaries (Orlando, et al., 1993). For most Of the coast, the summer or fall is
the low-flow season (Geraghty et al., 1973). The high-flow season is dependent on
large-scale climatological controls. For most of the Texas coast, spring is the high-
flow season, driven by direct precipitation and by the interaction of continental and
marine air. For the northern coast, from Louisiana to the Florida panhandle, the
winter and early spring are the high-flow seasons, due to precipitation, snow melt,
and river-channel transport in the great Midwestern watersheds. In Florida,
summer and early fall are the high-flow seasons, due to air-mass thunderstorms in
the peninsula's small watersheds. Also, in Florida, spring is frequently the low-flow
season (Orlando, et al., 1993).
Year-to-year variability in freshwater input to Gulf of Mexico estuaries is great,
responding to large-scale climate fluctuations that produce flooding and drought. In
some years, the high-flow period is pronounced and lengthy. In other years, it may
be completely absent. Although river discharges in the low-flow period are
pronounced and lengthy, in other years, they may be completely absent. Although
river discharges in the low-flow period are less variable than those in the high-flow
period, annual variability does occur. In some years, the low-flow period is
shortened or eliminated by unusual runoff; in other years, it is prolonged (Orlando,
et al, 1993).
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
26
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Table 2.6 Selected Characteristics for Long-Term Stream flow
Gages on Streams Discharging Directly to the Gulf of
Mexico
iGAGEl USGS |
|NO. I CAGE |
1 1 NO. 1
1
2
3
4
5
«
7
8
8
10
\ \
12
13
14
16
16
17
IB
18
2O
21
22
23
24
25
26
27
26
28
30
31
32
33
34
35
36
37
38
38
40
41
42
43
44
0847SOOO
0821 1000
08189SOO
08168500
08176500
08164000
08162500
081 14000
08075000
08074500
08066500
OB041500
08041000
08030500
O80 15500
08012000
08010000
07381480
07374000 '
07378500
07375500
07375000
02482000
024B8500
02478000'
02468761
02428SOO
02376500
02375500
02368000
02369000
02366500
02358500
02358000
02358000
02330000
02324500
02323500
02310000
O2304500
02301500
02300500
02288830
02296750
STREAM NAME AND LOCATION (LATITUDE.
I (OOMMSS)
•...,.-•
RIO GRANDE NEAR BROWNSVILLE. TEXAS
NUECES RIVER NR MATHIS. TEX.
MISSION RIVER AT REFUGIO. TEXAS
SAN ANTONIO RIVER AT GOLIAD. TEX.
GUADALUPE RIVER AT VICTORIA, TEX.
LAVACA RIVER NEAR EDNA. TEXAS
COLORADO RIVER NR BAV CITY. TX
BRAZOS RIVER AT RICHMOND. TX
BRAYS BAYOU AT HOUSTON. TX
WHITEOAK BAYOU AT HOUSTON. TX
TRINITY RIVER AT ROUAVOR. TX
VILLAGE CREEK NR KOUNTZE. TEX.
HECHES RIVER AT EVADALE. TEX.
SABINE RIVER NR RULXFF. TX
CALCAS1EU RIVER NR KINDER.- LA
BAYOU NEZPIOUC NR BASILE, LA
BAYOU DES CANNES NR EUNICE. LA
ATCHAFALAYA RIVER AT SIMMESPOHT. LA:
MISSISSIPPI R. AT BATON ROUGE. LA
AMITE RIVER NEAR DENHAM SPRINGS. LA.
'TANGIPAHOA RIVER AT ROBERT. LA
TCHEFUNCTA RIVER NR FOLSOM, LA
BOGUE CHITTO NR. BUSH.' LA
PEARL R NR BOGALUSA. LA
PASCAGOULA RIVER AT MERRILL. MS
TOUBIGBEE R AT COFFEEVILLE LID NR COFFEEVILLE AL
ALABAMA RIVER AT CLAIBORNE AL
PERDIOO RIVER AT BARRINEAU PARK. FL
ESCAMBIA RIVER NEAR CENTURY. FL
YELLOW RIVER AT MILLIGAN, FLA.
'SHOAL RIVER NR 'CRESTVIEW. FLA.
CHOCTAWHATCHEE RIVER NR BRUCE. FLA.
ECONFINA CREEK NEAR BENNETT. FLA.
CHIPOLA RIVER NR ALTHA. FLA.
APALACHICOLA RIVER AT CHATTAKOOCHEE FLA
OCHLOCKONEE RIVER NR BLOXHAM. FLA.
FENHOLLOWAY RIVER AT FOLEV. FLA.
SUWANNEE RIVER NEAR WILCOX. FLA.
ANCLOTE RIVER NR ELFERS. FLA.
HILLSBOROUGH RIVER NR TAMPA. FLA.
ALAFIA RIVER AT LITHIA, FLA.
LITTLE MANATEE RIVER NR WIHAUMA. FLA.
MYAKKA RIVER NR SARASOTA . FLA.
PEACE RIVER AT ARCADIA. FLA.
255235
280217
2B1730
263BS8
264734
285735
285826
283456
284148
284630
302530
302352
302120
301813
303010
302850
302900
3O5857
302929
302750
303023
303657
303745
304735
305840
314530
313248
304125 '
30S7S4
304510
304150
302703
302304
303202
304203
3O231O
300355
283522
261250
28012S
275218
274015
271425
2 7 V 3 i 9
LONGITUDE! PERIOD-OF-RECORD I
(ODMMSS) | .1
1 1
872715
875136
871644
872304
870046
8641 1O
860044
854527
852443
852349
945102
941548
840535
834437
825455
B237SS
922825
914754
81 1 ISO
805925
802142
901455
885350
894815
884335
880745
873045
872625
871403
863745
863415
855354
853324
8S095S
845133 '
843859
833429
825612
824000
822540
821241
8221 10
821850
R IH734
1934-68
1940-88
1940-88
1925-28.40-88
1936-88
1939-88
1939-88
1904-05.23-88-
1937-88
1937-86
1825-88
1825-27.40-88
1905-06.22-88
1825-88'
1923-24.39-88"
1938-88
1939-88
1935-88
1934-68
1938-88
1939-88
1943-88
1938-88
1938-88
1931-88
1929-88
1931-88
1942-88
1935-88
1939-88
1939-88
1931-88
1936-88
1922-27. 30-31. 44-88
1929-88
1927-88
1947-88
1942-88
1947-88
1939-88
1933-88
1940-88
1937-88
1 <* 17 - Rfl
YEARS | DRAINAGE |
OF | AREA |
RiCOHOt (MI y 1
55
49
49
53
S3
50
SO
68
52
52
64
51
69
64
52
60'
50
54
55
SO
60
46
51
SO
58
60
58
47
54
SO
50
58
53
S3
60
62
42
47
42
50
56
49
52
«i 7
335.500
16.660
690
3.921
5.198
817
42.240
45007
85
86
17.186
860
7.851
9.329
1.7OO
" 527
131
87.57O
1. 129. 8 1O
1 .280
646
96
1,213
6,573
6,590
18.417
22,000
394
3.817
624
474
4,384
122
781
17.200
1 .700
120
9.640
72
ESO
335
149
229
.3fi7
(Source: USGS, 1992)
Gulf of Mexleo Freshwater Inflow Action Agenda (3.1)
27
-------
Freshwater Inflow In the Gulf of Mexico
Chapter 2
TabI* 2.6 Annual Mean Stream flow, In Cubic Feet per Second, for
Long-Term Gages In Texas, 1947-86
I I
IVEAR |
1*47
1«48
1848
1880
1861
1052
1863
18S4
10B6
1056
1*57
1*50
I»6B
i860
1961
10(2
1863
1184
1005
ttee
1187
1888
1*00
1*70
HT1
1872
1»73
1t74
187S
1*76
1077
1*70
1878
1*10
1»il
1882
1*13
1884
1**B
1016
1
2480
2244
3885
138*
1008
423
B2S
641
161
B3
• •
123
• 280
BOB
606
387
172
132
181
1137
4284
28BB
383
24B
1210
3814
2B38
1482
3484
3333
3281
381
4288
378
2171
1103
400
246
282
183
2
1273
148
122B
340
583
244
.741
466
13S
164
1882
1S38
628
S02
847
111
108
104
787
4S2
2167
1232
138
718
2138
1780
714
1244
662
BSD
14EG
307
488
771
1268
478
146
145
378
395
3
131.0
8.2
33.0
4.2
38.0
08.0
42.0
18.0
7.0
8.0
10B.O
146.0
S6.O
• 7.0
196.0
42.0
11.0
14.0
46. O
126.0
631. O
203.0
• 3.0
8O.O
371.0
233.0
247.0
278.0
30.0
100.0
236.0
76.0
136.0
116.0
278.0
241.0
108.0
110.0
77.0
21.0
4
966
312
SS7
364
306
456
353
143
teo
88
874
874
B97
428
884
374
186
288
676
383
1 165
1141
G36
507
354
886
1505
1365
1148
837
1672
826
1356
552-
1064
648
470
267
647
74O
5
2203
702
1204
1061
542
818
1074
S48
374
132
1873
3541
1580
1764
3865
.814
565
566
1812
1S51
1225
2821
1817
1787
660
2410
2667
2844
3506
2189
3837
1461
3460
1020
3026
1614
1124
479
1600
1827
6
346.0
157. 0
146.0
126.0
47.0
162.0
163.0
23.0
14O.O
6. 1
244.0
514.0
306.0
278.0
966.0
234.0
63.0
74. O
349.0
28O.O
178.0
516. O
440.0
289.0
221.0
483.0
656.0
564.0
412.0
209.0
573.0
329.0
766.0
175. 0
473'. 0
556.0
409.0
128.0
357. 0
195.0
CAGE
7
3090
1246
1S99
21 19
700
616
1273
651
1014
84O
S96O
6200
2491
4B27
5743
1525
70S
375
2051
2061
S44
4900
200O
3523
929
1606
2641
3066
6862
1765
3974
866
3056
936
3012
2400
1623
658
1892
1896
NUMBER
a
8765
2687
464S
5763
1418
1820
4105
2727
2166
2158
15288
1 1865
4450
6869
16125
4508
2759
1715
10263
8791
1666
13227
• 219
6459
1679
4374
9283
7677
13957
5816
10741
1693
11487
4307
5053
7629
5462
1403
6540
8379
9
131
47
67
170
17
23
78
44
40
23
61
81
114
138
176
71
86
65
50
146
SS
1S2
12O
140
145
146
283
186
202
166
177
ISO
325
180
220
186
346
173
244
239
10
1 14
25
45
129
1 1
18
57
39
22
13
37
70
90
67
167
55
46
38
28
76
26
75
70
69
71
84
178
129
142
96
109
91
161
98
145
95
212
89
156
158
11
9681
6167
5566
11075
2387
2778
SSI'1
1694
2835
121 1
12689
11685
4809
6621
10442
4469
3495
1612
7333
8946
1771
1 1519
10387
4657
730
.5377
1 1295
997O
14661
5317
7977
2472
9966
561 1
4393
1 1626
6618
32SO
8094
104OI
12
1274
448
769
2248
265
492
1058
309
402
258
458
967
447
S24
1561
531
339
518
220
708
256
517
768
301
190
833
1790
1529
1685
771
683
545
2013
1060
68B
461
1415
979
736
1015
13
10000
4802
5030
1 1371
2042
3718
8177
21 14
3149
1608
4607
8465
5162
4728
10409
S174
2153
2603
1659
3354
1612
5*126
8378
2362
1 128
2461
9634
10396
9905
4432
4742
2325
10265
7282
2342
3513
8637
5417
5020
6206
1
14 1
1 1783
8193
8636
15944
4374
6415
12335
4097
5574
3421
9645
12294
6723
6545
12410
7500
2831
3250
4081
7553
1959
4560
12324
4132
2635
6465
13342
12099
14205
5941
5988
3681
12058
9010
2890
42SI
1 1800
6914
7069
7516
MEAN
744 122.0
I72O 319.0
7561
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
28
-------
Freshwater Inflow In the Gulf of Mexico
Chapter 2
Table 2.7 Annual Mean Stream flow, in Cubic Feet per Second, for
Long-Term Gages In Louisiana, Mississippi & Alabama,
1947-86
I
I YEAR
1947
1948
1949
1950
1951
1952
1953
1954
1965
1956
1957
1958
1959
ieeo
1961
1962
1963
1964
196S
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
tBEl
1982
1983
1984
1985
1966
1
1 IS
3221
1786
3822
3972
1322
1966,
4589
1470
2609
1463
2098
3538
1863
,1363.
3365
2507
1220
1731
1540
2249
1921
2230
2279
766
1790
2317
4517
3407
3832
1963
1707
2012
3337
3555
1052
1 145
4979
2966
2959
2308
16
1067
623
1036
S7O
263
477
1169
330
1166
343
688
985
778
633
1280
646
364
769
603
762
551
635
916
323
792
958
1639
1302
1222
522
706
719
1302
124G
359
575
1412
836
839
676
17
3O7
213
260
331 "
103
155
370
87
366
133
255
263
3O5
149
367
249
165
319
213'
276
266
196
301,
146
317
353
499
361
355
172
254
186
357
344 '
1 15
208
523
240
285
271
18
194395
173563
219467
278450
2408B1
215898
158535
88910
138219
131592'
201285
240767
148486
166813
208141
243621
126057
9O484
182038
139792
157025
216866,
228299
203556
196496
208030
383427
320455
321 197
180123
130951
218458
287973
212046
150671
21201 1
296373
254320
243419
215477
19
455981
421691
552844
674326
607417
538380
383458
242644
364605
340694
470781
S373O4
3541.18
447678
460603
623378
290290
341481
41 1375
3781 15
361263
445552
460280
4M926
404345
41327'!
726071
632499
598943
403281
312907
508030
663170
489057
352923
501899
676918
S9S6SO
564153
501975
20
2483
2330
3469
2198
1858
929
2781
1202
1880
1548
1 146
2218
1794
1405
2341
2342
669
1813
1859
2445
1485
965
1584
970
1430
2224
3063
2600
3158
1343
2713
2446
3104
3582
1287
1387'
4433
1745
2074
1696
GAGE
21
1515
1459
1915
1212
1O50
6O4
1255
902
922
910
746
1231
1035
914
1594
1671
525
1062
949
1337
762
555
920
554
1071
1335
1742
1651
1708
718
1281
1313
1580
1775
798
900*
2258
1OOO
1052
812
NUMBER
22
.234
227
313
169
143
83
194
152
90
1 19
102
178
138
1 1 1
230
253
77
144
123
183
102
62
1 17
75
129
195
230
256
217
93
191
182
185
193
91
97
291
134
120
66
23
2797
2356
3356
2292
1760
995
2081
1233
1468
1383
1 172
2089
1664
1630
2696
2775
919
1530
1621
21 16
1241
1069
1425
928
1684
2282
3 184
2954
3141
1453
1943
2102
2519
3081
1318
1426
3697
1872
1837
1490
24
1 1738
9229
17926
1 1562
6947
4013
9801
4770
69O7
7734
5678
12340
7191
8450
11288
14500
3412
8462
8266
9067
4278
7859
7244
5035
10157
10336
15322
17536
16327
10774
10309
1O698
16877
18833
56O3
6526
22555
10661
8796
5728
25
13564
12598
19408
9390
8176
5428
9O2S
6494
5061
6330
4647
13215
8062
9760
15247
13929
3716
8631
8532
10571
4704
6479
8349
5160
10448
10148
14253
15391
15842
9800
10864
9854
15432
19380
6475
6746
18640
9624
7436
7466
26
34499
30221
46694
30526
31638
19455
24606
14209
19428
20687
21317
36120
2O447
25362
33557
38543
14987
32795
2SS48
20509
14733
31112
23183
23616
28774
23472
42352
40672
40121
33940
29618.
27690
40672
487 1 2
15986
23909
57425
35415
21301
1 1642
27
36744
34601
53973
25063
25923
29542
32034
22008
22081
23099
26769
35393
23951
28440
40831
41423
28986
43428
31376
30286
26548 *
33876-
26331
24235
37044
34631
47626
34489
48726
46006
35492
33683
'44259
44757
18773
30859
451 12
43132
21 139
14441
1
281
1 1O9
910
1059
753
600
' 552
579
550
554
496
637.
670
771
803
990
886
569
771
699
726
608
371
726
670
734
446
783
824
1068
902
692
1 064
960
1 144
628
522
1050
621
648
732
MEAN 2469
813
266 206164 470737 2050 1165
157 1965 10069 10107 28908 33278
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
29
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Table 2.8 Annual Mean Stream flow, in Cubic Feet per Second, for
Long-Term Gages In Florida, 1947-86
\ 1
IVEAft 1
1*47
1848
1848
1050
10S1
1882
1053
1»S4
1»SB
10SC
1057
toss
1000
1880
ttei
1002
18*3
l**4
106&
1000
1007
10*1
loao
1*70
1071
1073
1*73
1074
1976
187«
1077
107i
1070
10»0
1011
1002
1003
100*
1005
isse
39
0580
7464
0803
3630
3201
X653
4509
S200
3801
3053
5023
B007
SS32
• 43S
7013
8150
3B49
• •02
•750
8123
4225
210O
3S1S
•47S
7427
4467
103*8
• 70S
H695
0057
ei4S
• 387
7830
•804
3128
B302
• ••4
•413
4304
BOO1
30
1C75
1S84
1388
• 08
• 25
773
• 21
1308
BOB
72S
1278
• SO
1047
1388
1414
1153
• ••
1506
1108
1010
712
eio
• 03
1303
11B7
702
I7BS
1004
2206
1784
1130
1748
1307
1330
BOS
• 88
1355
1080
888
840
31
1372
1516
1461
870
667
681
848
11 Be
BS1
703
860
1004
1173
1645
127S
1O23
876
160S
1325
1058
675
766
797
1087
887
571
1331
1232
1661
1B47
1137
1761
1107
1163
64B
886
1321
1021
761
10SS
32
9869
11624
11252
E600
3830
BS41
B666
72SS
3*93
3454
6124
0986
6338
8402
7015
6216
S071
10982
8769
7422
B162
451O
4455
7271
8362
5390
10S6S
6801
103*5
9390
7610
10842
803S
8231
3841
5842
8000
7000
4076
8002
33
S79
7S8
674
S53
4S7
464
480
625
379
376
451
673
593
626
525
4SO
454
634
6*4
596
482
414
428
531
S13
454
563
477
572
550
553
614
637
624
464
441
564
629
470
614
34
2021
2977
2066
1221
868
1 179
1 157
1264
613
7S4
1048
1874
1S04
1822
1329
1 179
1 1S9
2247
2158
1597
1294
759
911
1350
1264
1235
1952
1213
1927
151 1
1523
1921
1861
1864
806
1 192
201 1
1930
785
1529
35
23877
33514
35510
1621O
12155
20279
20891
18696
1 1283
12442
15680
22529
20762
25068
2367*
22218
17676
34643
31O6I
26875
21 138
17671
15696
19180
26572
22108
33322
236O2
32718
26452
24037
26096
2237*
25417
12661
1870*
29130
29394
14508
14303
GAGE NUMBER
36 37
1797
4516
2293
1O01
651
1401
1097
1019
315
640
948
2626
21O9
2522
1810
766
1153
2937
4325
2583
1324
430
1430
206O
1488
1374
3082
1378
2413
1943
1959
15S2
1989
2001
628
1378
2197
2880
816
2760
52
223
107
21
30
99
144
82
51
60
141
199
177
185
126
78
1 17
317
170
185
1 1 1
75
122
256
104
147
180
123
109
97
157
I 17
97
147
106
146
192
183
121
16O
38
9856
24560
1298S
7600
6704
9179
7486
9290
4261
4640
6201
13208
13689
12634
10588
7142
7172
15045
19269
15043
9549
5301
6335
13297
9080
1 1918
'15562
8554
12761
6546
12056
10872
8657
10757
5612
8234
13656
17141
6887
12517
39
111 .O
88.0
86.0
69.0
29. O
58.0
1 13.0
71 .0
32.0
20. 0
87.0
101 .0
228.0
200.0
44.0
36.0
67. 0
135.0
77.0
57.0
49.0
53.0
75. 0
112.0
65.0
21 .0
22.0
92.0
32.0
57.0
11 .O
46.0
95.0
26.0
8.9
95.0
62. 0
64. 0
37.0
65.0
4O
793
614
452
658
333
371
852
781
264
102
588
601
1546
1718
327
484
425
937
614
696
422
41 1
469
742
148
119
214
492
231
343
63
337
328
274
80
315
495
337
159
310
41
576
492
441
228
2O2
188
532
480
236
136
442
424
792
845
270
346
393
383
350
395
375
414
369-
450
237
259
335
327
217
324
143
256
472
327
179
277
426
29O
139
193
42
273
229
177
137
14*
95
271
220
140
40
171
221
41 1
319
81
203
191
133
153
124
159
218
160
149
1 1 1
150
203
1 17
8*
57
86
188
164
122
155
231
264
1 1*
75
108
43
5*3
287
389
179
98
116
390
29*
160
73
289
332
579
5*6
157
302
173
163
276
200
232
288
292
319
149
215
231
223
125
169
202
277
20*
IBS
191
31*
373
1*4
93
102
44
2*03J
1678
17591
7001
999J
7571
2301
2213
71*
392
1455
1482
2381
257 ll
101*1
9tol
90*1
972J
eol
12421
7221
125?!
tosel
144ll
61*1
6«ol
1000!
10S9J
*72
82*
** ll
10621
9101
76*1
2981
I362J
1*79!
71*1
30?l
520!
HCAH
• 175
1143
1083
10637
(Source: USGS, 1992)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
3O
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Annual Mean Discharge. Temporal changes in streamflow to the Gulf of Mexico were
determined by statistically comparing annual mean streamflow values for early and
late periods of the period of record. Values for annual mean streamflow represent
annual volumes of streamflow to the Gulf of Mexico. Increases in streamflow for
the later period occurred at 29 of the gages while decreases occurred at 15 of the
gages. Eight of the streams had increases in discharge that exceeded 25 percent.
Increases in streamflow for Brays and Whiteoak Bayou in Houston, TX, are probably
related to increases in urbanization in those watersheds. The causes for increases at
the other gages were not investigated. The largest percentages in decreased
discharge occurred at gages in southern Florida. Decreased streamflow in west-
central Florida is attributed to rainfall deficits in that area during the 1960 and 1970
decades. Rainfall deficits have continued in west-central Florida in the 1980s.
However, flows in the Peace River in Florida have been declining in excess of that
expected from rainfall deficits alone (USGS, 1992).
Annual Maximum and Minimum Discharge. Temporal changes in maximum and.
minimum streamflow to the Gulf were determined by comparing annual
maximum and minimum daily mean discharges for early and late periods at each
gage. This analysis is important because maximum and minimum discharges may
impact marine life in the Gulf of Mexico as much as annual mean volumes (USGS,
1992).
Increases in annual maximum discharges for the later period occurred at 24 of the
gages while decreases occurred at 20 of the gages. Large increases or decreases
occurred at many of the gages. All but two of the gages -with decreased maximum
discharges are in Texas and Florida. Increases in maximum discharges exceeded 50
percent for the Mission River, Brays Bayou, and Amite and Tangipahoa Rivers.
Decreases exceeded 20 percent for the Rio Grande, Brazos, Neches, and Sabine Rivers
in Texas, and the Anclote, Hillsborough, Alafia, Little Manatee, Myakka, and Peace
Rivers in Florida. Causes for decreased maximum discharges to the Gulf of Mexico
from Texas streams were not investigated.
While the flow of the Hillsborough River may have decreased by more than 20
percent over the period of record, the record is based on gage data upstream of the
City of Tampa's reservoir. Discharges of the reservoir to tidal waters have been
much lower than instream flows above the dam (Eckenrod). Similarly, the annual
mean flow of the Little Manatee River has not changed over the period of record,
but minimum flows have increased significantly because of agricultural tail-water
runoff. Farms use deep aquifer water that is highly mineralized, so the chemistry of
dry-season river flows has been affected, as well as discharge rates (Eckenrod).
Increases in annual minimum discharges for the later period occurred at 27 of the
gages while decreases occurred at 17 of the gages. Large increases occurred at many
of the gages. Decreases exceeding 20 percent occurred for the Colorado River in
Texas, and the Anclote, Hillsborough, and Peace Rivers in Florida.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
31
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Inflow to Contra! Gulf. The Louisiana estuaries on the west side of the Mississippi
River are a series of bar-built systems in which freshwater is generally dispersed
throughout the system by numerous small channels or bayous. The freshwater
input into these systems is not well known. To the east of the Mississippi River,
two major freshwater sources from rivers entering the Mississippi Sound on the
western end include the Pearl and the Pascagoula Rivers, which supply about equal
volumes of mean flow (USAGE, 1983). Additional freshwater is also supplied from
several smaller rivers in Mississippi, as well as several rivers entering Lake
Pontchartrain, thus supplying freshwater to Lake Borgne through the tidal passes at
the east end of Lake Pontchartrain. The picture is quite different on the eastern end
of the Sound where the Mobile River supplies freshwater at an average rate of about
63,558 ft3/second (1,800 m3/second) (Isphording, et al, 1983). The impact of these
rivers on the salinities in both the estuaries and Mississippi Sound is large and in
general follows a seasonal pattern, with highest salinities in summer and fall during
low-river flows, and lowest salinities in winter and spring during high-river flows
(Orlando, et al, 1993).
Inflow to Eastern & Western Gulf. In the more arid sections of the Gulf of Mexico
coast (i.e., Texas and Florida), river flow is governed by surface runoff generated by
storms, and this flow is highly variable so that rivers exhibit large, sudden
excursions. The greater frequency and intensity of precipitation in estuaries of the
Upper Texas and Florida panhandle coasts, along with the detention created by
reservoirs, lead to considerable overlap in individual storm pulses. Hence, the
freshwater inflow hydrography in these estuaries is typically manifested as a
seasonal runoff surge of several weeks to a few months in duration. Further south
in Texas and Florida, runoff pulses become more isolated in time, and the inflow
appears as a series of nearly discrete flood pulses (Orlando, et al., 1993).
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
32
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Factors Related to Changes In Streamflow
Freshwater inflows are altered in several ways. The amount of inflow can be
decreased or increased. Decreases accompany impoundment projects and diversions
for consumptive uses. Increases tend to be caused by flood control projects,
deforestation, urbanization, and agricultural development. The inflows can be
changed on an annual basis or seasonal basis. Inflows can also be altered in two
other important ways. The timing of inflows can be changed, even if the amounts
are not, and the location of inflows can be changed, even if the amount and time are
not. Alterations in freshwater inflows that have occurred as part of land
development and water management in watersheds influence the productive
capacity of the estuaries downstream. Such alterations have occurred worldwide.
A number of anthropogenic changes have been made to the natural flow pattern
within each watershed that flows into the Gulf of Mexico. Dams have been built on
streams for flood control, water supply, and recreation. Water from streams is used
to grow crops, lawns, shrubs, and flowers. Water is moved from one watershed to
another to satisfy changing needs. In addition, drainage facilities have been built to
move large amounts of water quickly to streams and bays. Also having a significant
impact on water resources are roads, clear cutting of heavy vegetation, and
development near water sources. Freshwater changes have caused a tremendous
loss of marine productivity in many areas. Recent studies along the Texas coast
indicate freshwater inflow rates affect the relative abundance of various species of
phytoplankton and the relationship between estuarine chlorophyll concentrations.
Reservoirs are located on most of the major rivers flowing into Gulf of Mexico
estuaries. The presence of reservoirs indicates diversion of water for human use,
which may be important to the freshwater budget of an estuary. Reservoirs affect
the timing and fluctuations of river flow. They can decrease the amount of flow
variation of a river, particularly because natural peak flows are held back and
released in smaller quantities over a longer period of time. In specific low-flow
periods (i.e., summer), the relative effect of the reservoirs may be much greater since
the low-river is even further reduced (Orlando, et al., 1993). For rivers in the more ;
arid segments of the Gulf, it is arguable whether the natural river flow at low-flow
levels could have any impact on salinities even without reservoirs (Orlando, et al.,
1993). The effect of these reservoirs on average estuarine salinities is controversial,
but it is believed to be less important than other factors (i.e., seasonal variation in
marine and terrestrial climates, or the presence of navigation channels connecting
estuaries with the Gulf) (Orlando, et al., 1993). Reservoirs also reduce sediment
loads delivered to estuaries.
Dredging of river channels to improve either navigation or drainage has reduced
the flooding of and sediment distribution into those stream delta estuaries. This
reduces the ability of the stream to naturally maintain elevations of subsiding
wetlands and to offset wetland loss in those estuaries.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
33
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
Impacts of Alterations In Freshwater Inflows
The historic approach of unlimited freshwater withdrawals from rivers eventually
leads to chain reactions that destroy estuarine ecosystems (Rozengurt and Haydock,
1991). Fundamental relationships that are affected (see Figure 2.4) are as follows:
Q Estuarine circulation is partly dependent upon freshwater inflows.
This can be particularly important in estuaries experiencing low tides,
such as those in the Gulf of Mexico.
Q Coastal wetlands depend upon sediments carried by freshwater
inflow to counteract coastal erosion and subsidence processes and sea
level rise.
Q Decreased freshwater inflow leads to increased salinization of coastal
aquifers and soils. Saltwater intrusion also destroys freshwater
wetlands.
Q When coupled with increased nutrient loads from sewage and
agricultural runoff, increased light penetration resulting from
reduced silt loads promotes algal blooms.
Q Effects of pollutants increase in the absence of sufficient fresh water
for adequate dilution. High evaporation rates and poor mixing
aggravate the problem with pollutants.
Q The end result is a reduction in biological productivity and alarming
decreases in landings of fish and shellfish (Rozengurt and Herz, 1981).
The clearest example of the ecological and economic effects of large scale diversion
of freshwater inflows comes from the southern part of the former Soviet Union
(Rozengurt and Herz, 1981; Rozengurt et al., 1985; Rozengurt and Haydock, 1991).
The USSR built 30 major dams on rivers flowing into the Black, Caspian, Azov, and
Aral Seas. These dams hold back 30-97 percent of stream flow to these systems. The
dams have destroyed fish migration routes and spawning and nursery grounds.
They have eliminated 90-98 percent of the valuable species of commercial fish in all
the major rivers and estuaries of the southern USSR (Rozengurt et al., 1987).
Attempts to restore fish stocks in these systems have failed. Within just 20 years,
the Aral Sea changed from one of the most productive seas in the world to a virtual
desert. Economic losses associated with the devastation to the lake and surrounding
countryside amounted to $6.5 billion annually.
According to Rozengurt and Haydock (1991), the Gulf of Mexico already has been
deprived of 40-90 percent of spring runoff from 44 rivers and 30 estuaries. In
addition, agricultural runoff, industrial discharges, and traffic and other activities
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
34
-------
Freshwater Inflow in the Gulf of Mexico
Chapter 2
associated with six of the nation's top seaports stress the coastal Gulf of Mexico
environment. The distortion of natural coastal dynamics caused by direct and
indirect manipulation of freshwater flow may be responsible for oxygen deficient
waters. Up to 9,500 km2 (4,000 mi2) of oxygen deficient (hypoxia) bottom waters,
known as the "dead zone," have been documented off the Louisiana and Texas
coasts (Rabalais, et al., 1991).
Gulf of Mexico harvests of several high valued species, including red drum, red
snapper, king mackerel, and pink shrimp declined in the 1980s (Browder et al., 1991;
Brown et al., 1991), and some stocks still have not recovered. For instance, landings
of pink shrimp from the Tortugas grounds of southern Florida are at an all-time
low. Roughly 52 percent of the Gulf of Mexico's classified shellfish-growing areas
are closed to harvest, at least in part because there is insufficient runoff to flush out
natural and human-induced contaminants that have accumulated (Duke and
Sullivan, 1990). Freshwater-related ecosystem degradation in South Florida and
Texas is now so great that it threatens multi-billion dollar fishery and tourism
industries.
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
35
-------
Ffeshwat&r Inflow In the Gulf of Mexico
Chapter 2
2.4
Conceptual Chain Reaction Between Spring River
Runoff & Some Major Chemical, Physical &
Economic Parameters In Delta-Estuary-Sea Economy
SPRING RIVER RUNOFF
(% of normal)
ESTUARINE SALINITY
(tlnws)
ORGANIC AND
INORGANIC MATTER
£30%
1850
I860 1070 1880
YEARS
1990 2000
a. Range of natural limitations in spring freshwater diversions (£3O%
of normal).
b. Detrimental range of spring diversions for living and non-living
resources (SO% of normal).
c. Range of residual spring runoff irrevocably damaging to
environment and economics of ecosystems (75%S of normal).
(Source: Rozengurt and Herz, 1981)
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
36
-------
Freshwat&r Inflow in the Gulf of Mexico
Chapter 2
State-by-State Overvlow
Alabama
The Alabama coastal zone is distinguished from both the Texas and Florida coastal
zones by a much greater influx of freshwater (Orlando et ol., 1993). The Alabama
coastal zone is characterized by a series of barrier islands and bays. However, these
bays are surrounded only by fringing salt marshes as opposed to the extensive
wetland systems found along the Louisiana coast.
General Description of Mobile Bay and the Alabama Gulf Coast. Mobile Bay is a
submerged river valley estuary. The boundaries of the estuary are defined from the
head of tide on the Alabama and Tombigbee Rivers at Claiborne and Coffeeville,
respectively, to the estuary's terminus with the Gulf of Mexico at Main Pass and Pass
aux Herons. Mobile Bay is oriented on a north-south axis, perpendicular to the Gulf
of Mexico. The bay in general is relatively large, shallow, and wide. Mobile Bay is 50
km (31 mi) in length, 34 km (21 mi) in width, and has a depth of approximately 3 m
(9.8ft). The bay has a total drainage area of 115,510 km2 (44,598 mi2).
The Alabama coast line east of Mobile Bay on Dauphin Island consists of white
sandy beaches backed by dunes. West of the Bay the coast line, which fronts the
Mississippi Sound, is low and marshy with numerous bayous and tidal flats.
Freshwater Inflow. Major tributaries entering Mobile Bay are the streams in the
Mobile River Delta, Dog and Fowl Rivers on the western shore, and Fish and Bon
Secour Rivers on the eastern shore. The upper tidally influenced reaches of the
system form an extensive delta region as the Mobile River enters the bay through
these three major tributaries accounting for run-off associated with 90 percent of the
drainage basin. The average daily flow (gaged at Claiborne and Coffeeville, AL) to
Mobile Bay was 1,848 m3/second (65,253 ft3/second) for the period 1929-1983. The
ungaged portion of the Mobile River System watershed is estimated to contribute an
additional seven percent of freshwater inflow to the Bay.
Several patterns exist that affect freshwater inflow to the bay. First, over 95 percent
of the freshwater enters the bay via the Mobile River System. Highest freshwater
discharges occur generally from February to May, corresponding to periods of lowest
bay-wide salinities. Second, water exchange with the Gulf of Mexico occurs
primarily (85 percent) through the Main Ship Channel, although its location is
determined by the magnitude of freshwater discharge and tidal phase. Third, a bay-
wide vertical salinity gradient is usually apparent throughout the year but may vary
significantly depending on the phase of the tide and wind conditions.
Salinity Characteristics. In Mobile Bay the dominant time scale over which salinity
varies is seasonal. Freshwater inflow is the principal mechanism that decreases
average system salinities, and it tends to stratify the water column during the high-
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
37
-------
Freshwater Inflow In the Gulf of Mexico
Chapter 2
flow period of February to April. Average winds at this time are from the north at
4-5 m/second (13-16 ft/second) and tend to enhance stratification further. During
the low flow period of August through October, average system salinities increase
and destratification occurs as wind and tide more effectively induce mixing.
To a lesser degree salinity variability is experienced on a time scale of days to weeks.
Wind associated with frontal passages, typically occurring from October through
March, is an important mechanism. Changes in salinities occur as winds rotate,
mixing the water column and affecting system exchanges with adjacent shelf waters.
In addition, bimonthly spring tides induce greater pulses of Gulf of Mexico waters
which increase salinities and mixing. Low to slight variability is observed at time
scales of hours to days. Tides have only a localized influence that is mainly
confined to the mouth of Mobile Bay. Overall Mobile Bay is classified as a seasonal
estuary due to a strong seasonal freshwater inflow signal, but it is susceptible to
shorter term fluctuations as determined principally by wind.
Agriculture and Commercial Trade. The Mobile metropolitan area has abundant
natural resources that support a wide range of business and industry. Major
industries include paper and paper products, shipbuilding, chemicals, lumber
products, computer hardware and software, and textiles. The Port of Mobile
supports a major shipping industry.
Baldwin County and Mobile County outside the Mobile metropolitan area are
largely agrarian, with potatoes, soybeans, corn, vegetables, pecans, and pulpwood
being major sources .of income. The seafood industry is an important means of
livelihood for the residents of the communities along the bayous and bays in lower
Mobile and Baldwin Counties. Also the beaches on Dauphin Island and along the
Gulf shore of Baldwin County have fostered an appreciable tourist and vacation
trade.
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State-by-State Ovorvlow
Alabama
The Alabama coastal zone is distinguished from both the Texas and Florida coastal
zones by a much greater influx of freshwater (Orlando et ul., 1993). The Alabama
coastal zone is characterized by a series of barrier islands and bays. However, these
bays are surrounded only by fringing salt marshes as opposed to the extensive
wetland systems found along the Louisiana coast.
General Description of Mobile Bay and the Alabama Gulf Coast. Mobile Bay is a
submerged river valley estuary. The boundaries of the estuary are defined from the
head of tide on the Alabama and Tombigbee Rivers at Claiborne and Coffeeville,
respectively, to the estuary's terminus with the Gulf of Mexico at Main Pass and Pass
aux Herons. Mobile Bay is oriented on a north-south axis, perpendicular to the Gulf
of Mexico. The bay in general is relatively large, shallow, and wide. Mobile Bay is 50
km (31 mi) in length, 34 km (21 mi) in width, and has a depth of approximately 3 m
(9.8 ft). The bay has a total drainage area of 115,510 km2 (44,598 mi2).
The Alabama coast line east of Mobile Bay on Dauphin Island consists of white
sandy beaches backed by dunes. West of the Bay the coast line, which fronts the
Mississippi Sound, is low and marshy with numerous bayous and tidal flats.
Freshwater Inflow. Major tributaries entering Mobile Bay are the streams in the
Mobile River Delta, Dog and Fowl Rivers on the western shore, and Fish and Bon
Secour Rivers on the eastern shore. The upper tidally influenced reaches of the
system form an extensive delta region as the Mobile River enters the bay through
these three major tributaries accounting for run-off associated with 90 percent of the
drainage basin. The average daily flow (gaged at Claiborne and Coffeeville, AL) to
Mobile Bay was 1,848 m3/second (65,253 ft3/second) for the period 1929-1983. The
ungaged portion of the Mobile River System watershed is estimated to contribute an
additional seven percent of freshwater inflow to the Bay.
Several patterns exist that affect freshwater inflow to the bay. First, over 95 percent
of the freshwater enters the bay via the Mobile River System. Highest freshwater
discharges occur generally from February to May, corresponding to periods of lowest
bay-wide salinities. Second, water exchange with the Gulf of Mexico occurs
primarily (85 percent) through the Main Ship Channel, although its location is
determined by the magnitude of freshwater discharge and tidal phase. Third, a bay-
wide vertical salinity gradient is usually apparent throughout the year but may vary
significantly depending on the phase of the tide and wind conditions.
Salinity Characteristics. In Mobile Bay the dominant time scale over which salinity
varies is seasonal. Freshwater inflow is the principal mechanism that decreases
average system salinities, and it tends to stratify the water column during the high-
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flow period of February to April. Average winds at this time are from the north at
4-5 m/second (13-16 ft/second) and tend to enhance stratification further. During
the low flow period of August through October, average system salinities increase
and destratification occurs as wind and tide more effectively induce mixing.
To a lesser degree salinity variability is experienced on a time scale of days to weeks.
Wind associated with frontal passages, typically occurring from October through
March, is an important mechanism. Changes in salinities occur as winds rotate,
mixing the water column and affecting system exchanges with adjacent shelf waters.
In addition, bimonthly spring tides induce greater pulses of Gulf of Mexico waters
which increase salinities and mixing. Low to slight variability is observed at time
scales of hours to days. Tides have only a localized influence that is mainly
confined to the mouth of Mobile Bay. Overall Mobile Bay is classified as a seasonal
estuary due to a strong seasonal freshwater inflow signal, but it is susceptible to
shorter term fluctuations as determined principally by wind.
Agriculture and Commercial Trade. The Mobile metropolitan area has abundant
natural resources that support a wide range of business and industry. Major
industries include paper and paper products, shipbuilding, chemicals, lumber
products, computer hardware and software, and textiles. The Port of Mobile
supports a major shipping industry.
Baldwin County and Mobile County outside the Mobile metropolitan area are
largely agrarian, with potatoes, soybeans, corn, vegetables, pecans, and pulpwood
being major sources of income. The seafood industry is an important means of
livelihood for the residents of the communities along the bayous and bays in lower
Mobile and Baldwin Counties. Also the beaches on Dauphin Island and along the
Gulf shore of Baldwin County have fostered an appreciable tourist and vacation
trade.
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Florida
The Florida coastal zone extends northwest to southeast along 1000 km (620,mi) of
coastline, from the tip of the Florida Panhandle down to the Florida Keys. A
spectacular diversity of rivers, estuaries, and coastal landscapes occurs along the
length of the Florida Gulf Coast. Patterns of freshwater inflow, salinity variation,
and human impacts to inflows and salinity can be described in terms of the four
latitudinal zones from the Florida Panhandle to the tropical waters of the Florida
Keys. Each is under the jurisdiction of a distinct water management district.
The "Panhandle." Florida's continental lands west of the peninsula comprise the
panhandle, a region rich in terms of water resources throughout the state. Eight of
the state's 15 largest rivers flow through northwest Florida; seven of these have
their headwaters in Alabama and Georgia. The combined average daily discharge of
all Panhandle rivers is approximately 1,218 m3/second (43,000 ft? /second). Estuaries
at the mouths of these alluvial streams are rich nursery grounds for a number of
species upon .which traditional fishery economies depend. Apalachicola Bay, for
example, produces 90 percent of Florida's oyster harvest (equal to ten percent of the
nation's harvest), and the Bay is a major producer of shrimp and blue crab.
The major threat to Florida's rivers and estuaries is the impact of upstream users on
the quantity and quality of water flowing to the Gulf of Mexico. Most of the
watersheds of Panhandle rivers have substantial portions (80 to 90 percent) outside
of Florida. Because other states control the majority of such watersheds, Florida has
little authority regarding the management, allocation, or protection of waters
entering the state. The needs of estuaries are not presently considered in any
management decisions being made in upper basin areas.
However, this situation is slowly changing. The state and federally funded
Apalachicola-Chatahoochee-Flint and Alabama-Coosa-Talapoosa Rivers
Comprehensive Studies are attempts to examine all water uses on each river
system, including the needs of estuaries for freshwater inflow. These studies bring
hope that basin wide management programs can be developed which would protect
water needs of natural resources and balance human needs within watersheds.
Unfortunately, there are competing demands for the water resources of the rivers.
For example, dams have been proposed on the main stem of some smaller
northwest rivers for flood control, hydropower, and recreation. If built, these
structures will alter the natural inflows of freshwater to estuaries and thereby alter
estuarine productivity and usefulness.
"Big Bend." Florida's curving Gulf shoreline along the northern peninsula is the
state's Big Bend region. The coastline, extending from Apalachee Bay on the north
to Waccasassa Bay on the south, has been described as a single, vast estuarine area.
Eight major streams discharge into the region-the St. Marks, Aucilla, Econfina and
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Fenholloway Rivers, Spring Warrior Creek, and the Steinhatchee, Suwannee and
Waccasassa Rivers. The eight streams have a combined average daily discharge of
approximately 368 m3 /second (13,000 ft3 /second) to this region of the Gulf. About 81
percent of this volume is accounted for by the Suwannee, the second largest river in
Florida (after the Apalachicola) in terms of discharge.
Freshwater also reaches the coast via smaller creeks and groundwater seepage as this
region is hydrogeologically a groundwater discharge zone. In fact, a distinguishing
feature of all streams draining to this part of the coast is that each receives
substantial amounts of ground water from the Floridian Aquifer (Florida's major
groundwater source). Because ground waters contribute to each estuary's salinity
regime, but also supply potable, agricultural, and industrial users, the potential
exists for competition between the water needs of rivers and estuaries and human
water needs. Several major industrial and agricultural groundwater withdrawals
currently exist in the area, but relationships between withdrawals and stream flows
have not been determined.
Evidence does exist that land uses affect stream flows in the region. Forestry is the
dominant land use in the watershed of the Steinhatchee River, for example.
Compared to basin conditions prior to timber farming, flows of the Steinhatchee
River are estimated to be five percent greater than normal on an average annual
basis. Peak flows are estimated to be as much as 35 percent greater because of
wetland conversion to pine forests and channelization. To date, few data have been
collected relating freshwater inflow to the biological characteristics of the region
(such as marsh or fisheries production). Quantitative description and analysis of
these relationships is a crucial need for proper management of Big Bend estuaries.
The Middle Peninsula. The fifteen rivers and numerous coastal creeks that drain
west-central Florida flow to one of three major embayments (Charlotte Harbor,
Sarasota Bay, Tampa Bay) or directly to the Gulf of Mexico. Their combined average
daily flow is approximately 198 m3 /second (7,000 ft3 /second). Six streams flowing to
either Charlotte Harbor or Tampa Bay have been impounded for use as public water
supplies. With one exception, dams were built within the natural extent of brackish
waters in these streams, creating salinity barriers that truncated estuarine and tidal
freshwater reaches. For three of these streams, these barriers probably represent the
most significant ecological impact because withdrawals have been relatively small.
Withdrawals, however, have resulted in significant flow reductions in three major
tributaries to Tampa Bay. Prolonged and substantial flow reductions occur in these
rivers during the dry season, especially the spring, which is a peak utilization time
for many estuarine-dependent species. Required flow releases for these reservoirs
are minimal or non-existent and prolonged flow reductions are often followed by
sudden releases in the wet season that cause dramatic salinity fluctuations in the
receiving estuaries. Similar effects of salinity are probably associated with two major
flood control channels (Tampa Bypass Canal and Cross Florida Barge Canal) that
periodically divert large quantities of freshwater to coastal habitats.
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Two other major withdrawals for public or industrial supplies in the region are
more ecologically sound, as.off-stream reservoirs are used for water storage.
Municipal supply withdrawals from the Peace River, the largest tributary to
Charlotte Harbor, have been the subject of much ecological review and this facility
serves as a prototype for future water use in the region. Withdrawals from the
Peace River cannot reduce streamflow by more than ten percent on any given day
and off-stream storage has been supplemented by pumping treated river waters into
underground aquifers for later retrieval.
The effects of lowered ground water levels on freshwater flows are a growing
concern. As in the Big Bend region, this is particularly true for rivers where there is
a good hydrologic connection with underlying groundwater aquifers. Long-term
analysis of rainfall relationships for the Peace River indicates that groundwater
pumping has reduced flows in the upper basin. Such effects depend on regional
hydrogeology, however, and in at least one other river (Little Manatee), excess
irrigation waters taken from groundwater sources actually supplement dry season
flows. Urbanization and channelization have probably also affected runoff rates in
highly developed areas around Tampa and Sarasota Bays. Although much of this
runoff is not measured, it is expected that urbanization has increased wet season
flows and, less conclusively, reduced dry season flows to estuaries.
Florida Bay. Florida Bay is located at the southern tip of Florida. Its eastern and
southern boundaries are defined by the arc of the Florida Keys and its northern
boundary is the coast of the Florida mainland. The many small embayments that
fringe the mainland from the southeastern Everglades to Gape Sable and open onto
Florida Bay are considered part of the Florida Bay system. The main body of Florida
Bay is made up of a number of shallow basins that are partially separated from one
another by a labyrinth of banks. Parts of this system become hypersaline during the
long South Florida dry season, whereas brackish water prevails in the extreme
northeastern part of the system during the wet season. Much of the Florida Bay
system lies Within the Everglades National Park. The biota of the Florida Bay :
system contains many tropical species, and coral reefs parallel the Florida Keys.
Historically, the Florida Bay system has been the nursery ground for the multi-
million dollar Tortugas pink shrimp fishery and the Florida Keys lobster fishery, as
well as an important recreational fishing area supporting spotted sea trout, red
drum, mangrove snapper, snook, and other desirable species- The past few years
have seen a number of dramatic changes, beginning in the mid-1980s. These
include the following: 1) a decline in both catches and catch per unit effort in the
Tortugas shrimp fishery; 2) a spreading die-off of seagrass that already covers a large
portion of central and western Florida Bay; 3) an enormous algal bloom; 4) a die-off
of sponges; and 5) localized fish kills. Seagrasses are a major habitat for early,
juvenile pink shrimp, and sponges are a major habitat for young spiny lobster.
The Florida Bay system is at the receiving end of the Everglades "river of grass" and
has likely been affected by the many changes that have been made to the natural
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Freshwater Inflow in the Gulf of Mexico
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flow of water through the Everglades. The most recent major change was the
completion of the South Dade Conveyance System in the early 1980s. This
conveyance system, as currently operated, lowers the water table in the southeastern
Everglades and adjacent east coast ridge. This has affected the flow of water into
Florida Bay.
Many knowledgeable South Florida scientists have concluded that changes in
freshwater discharges to the coast that influence the Florida Bay system are
responsible for the catastrophic changes in Florida Bay. However, there is some
disagreement among scientists. Some contend nutrient inputs to the Bay have
increased and that this might be responsible for the ecological disaster. The premise
that nutrient inputs to the Bay are higher than they have been historically has been
challenged. Thus far, the Florida Bay system has been neglected in previous multi-
agency efforts to determine relationships between water management practices and
ecosystem health and productivity in South Florida. Hopefully, the current crisis
will focus attention and resources to properly address and resolve the ecological
problems in this important estuarine system.
Summary & Conclusions. Imprinted upon the remarkable diversity of riverine and
coastal landscapes of Florida are several important latitudinal gradients related to
freshwater inflow and water management. Total flows are greatest in the
Panhandle and decrease with latitude, as does the relative contribution of ground
waters to surface water resources. The extent of inflow alterations and associated
ecological impacts also follow the same latitudinal gradient. The extent of river
flow alterations and existing ecological problems is least in the Panhandle, although
resource managers are greatly concerned over the potential for future problems.
The extent of inflow alterations and ecological problems in west central Florida is
moderate, and a crisis of national significance is unfolding in the Everglades and
Florida Bay.
Case Studies. Charlotte Harbor, (excerpted from Hammett, 1987) Charlotte Harbor is
a 699 km2 (270 mi2) estuarine system in west-central Florida. It is being subjected to
increasing environmental stress by rapid population growth and development. By
2020, population in the inflow area may double, which will result in increased
demands for freshwater and increased waste loads. The Charlotte Harbor inflow
area includes about 12,134 km2 (4,685 mi2). The Myakka, the Peace, and the
Caloosahatchee are the major rivers emptying into the harbor. About 70 percent of
the land in these three river basins is used for agriculture and range. In the coastal
basin around Charlotte Harbor, about 50 percent of the total land area is devoted to
commercial or residential uses. Water use in the inflow area is about 565 million
gallons per day, of which 59 percent is used for irrigation, 26 percent for industry, 11
percent for public supply, and four percent for rural supply.
Total freshwater inflow from the three major rivers, the coastal area, and rainfall
directly into Charlotte Harbor averages between 161 and 173 m3/second (5,700-6,100
), which is more than 13 billion litres (3,500 million gallons/day). A trend
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Freshwater Inflow in the Gulf of Mexico
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analysis of about 50 years of streamflow data shows a statistically significant
decreasing trend for the Peace River stations at Bartow, Zolfo Springs, and Arcadia.
No significant trend has been observed in the Myakka or the Caloosahatchee River
data. In the Peace River, the decrease in flow may be related to a long-term decline
in the potentiometric surface of the underlying Floridian aquifer system, which
resulted from ground water withdrawals. It is not possible to determine whether the
trend will continue. However, if it does continue at the same rate, then, except for
brief periods of storm runoff, the Peace River at Zolfo Springs could be dry year-
round in about 100 years.
By 2020, the population in the inflow area is expected to increase by more than
500,000 people. They will require an additional 288 million litres (76 million
gallons/day) for water supply.
Apalachicola River, (excerpted from Leitman et ol.) The Flint river joins with the
Chattahoochee River at the Florida border to form the Apalachicola River.
Maintenance of the base-flow of the Apalachicola River is important to the
ecological functioning of its floodplain and estuary and for the provision of a
federally authorized navigation project. Throughout the early 1980s, the
Apalachicola River's estuary provided about 90 percent of the state's and ten percent
of the U.S.'s oyster harvest and sizable shrimp, blue crab, and finfish yields. Annual
seafood landings are valued in the tens of millions of dollars, but the real value of
the estuary, however, is in its role as a nursery. The Apalachicola estuary's
productivity is the result of good water quality, physical form, salinity regime, and
energy subsidies in the form of nutrient/detrital transport from the river's
floodplain. It is keyed to a diurnal tidal cycle and a salinity regime defined by an
annual cycle of spring floods and winter low-flows and cyclical long-term
fluctuations in river flow (Livingston, 1984).
Based on recent analyses, it can be concluded that the base-flow of the Flint River
has been reduced since the early 1970s. As irrigation withdrawals accounted for the
majority of the increases in water use in the Flint basin, irrigation is the prime
suspect for causing this reduction. This reduction of base-flow would translate into
a parallel reduction of base-flow in the Apalachicola River. Because of the
ramifications of reduced freshwater inflow to Apalachicola Bay and to the
availability of the federal navigation channel, the issue of irrigation withdrawal
impacts on base-flow in the Flint and Apalachicola Rivers warrants closer
inspection. If the base-flow of the Flint has been lowered as the result of irrigation
activity, future withdrawals need to be controlled either through regulations or
market mechanisms.
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Louisiana
The Louisiana coastal zone is unique among all Gulf of Mexico states in that it
includes and is dominated by the single largest freshwater and sediment source of
the entire Gulf system—the Mississippi-Atchafalaya Rivers (Turner and Gosselink,
1975). The Mississippi and Atchafalaya Rivers, which drain about 40 percent of the
U.S. and parts of Canada, provide approximately 79 percent of Gulf of Mexico
freshwater inflow.
The Louisiana coastal zone consists of an extensive wetland system, which
comprises approximately 25-41 percent of all U.S. coastal wetlands, depending on,the
classification system used (Turner and Gosselink, 1975; Alexander, 1985). These
marsh systems are characterized hydrologically by numerous interconnecting lakes,
channels, and bayous. The flows through these channels are coupled with extensive
overland flooding, thus exchanging water between the marsh surface and the
surrounding waterbodies.
Whereas many Gulf estuaries suffer from upstream diversions of freshwater,
Louisiana's estuaries suffer from a different problem—entrainment of freshwater
and sediments to the main channels of the principal rivers. During the past sixty or
more years, the Mississippi and Atchafalaya rivers have been largely impounded by
levees and control structures, preventing the natural annual cycles of overbank
flooding that have nourished and maintained the most extensive wetland system in
the entire Gulf coast. (Overbank flooding of river water is a natural function that is
critical to estuaries.) A net sediment deficit in these wetlands is a principal cause of
the conversion of emergent wetland habitat to open water habitat [approximately 66
km2 /year (25 mi2 /year) at'present].
The Louisiana coastal wetland system has been eroding at a catastrophic rate during
the last 100 years, largely as a result of cultural modifications including: direct
development for residential, agricultural, or industrial uses; control of the natural
cycle of Mississippi River switching, preventing new delta lobe formation; river
leveeing for flood control, preventing overbank flooding and marsh nourishment;
construction of artificial channels with dredged spoil typically disposed offshore; and
canals, spoil banks, and other hydrological modifications, resulting in direct marsh
destruction and salt water intrusion. All the above hydrological modifications have
produced a net sediment deficit in a subsiding coastal zone which is also
experiencing sea level rise.
In recognition of the projected loss of most of its remaining coastal wetlands within
150 years, the state of Louisiana embarked on a coastal wetlands restoration effort in
1989, funded by dedicated state monies (Act 6). In 1990, a federal bill was signed that
established a federal-state effort to address the same problem. This bill, the Coastal
Wetlands Planning, Protection, and Restoration Act (CWPPRA) (see Appendix A),
dedicated approximately $33 million/year until 1999 to support a larger restoration
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Freshwater Inflow in the Gulf of Mexico
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effort, that includes artificial diversion of freshwater and sediment into wetlands ,on
a large scale from the Mississippi-Atchafalaya Rivers. At this time, the federal-state
task force under CWPPRA recognizes that the restoration of Louisiana's coastal
zone will be a very expensive undertaking, beyond the scope of presently authorized
funding.
Additional authorities will be sought in the future to tackle other aspects of the
restoration effort, such as constructing locks on navigation channels to block
saltwater intrusions. The restoration of Louisiana's barrier islands has been
identified as a key to maintaining much of the interior marsh system, but the island
restoration alone will probably cost $1 billion.
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Freshwater Inflow in the Gulf of Mexico
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Mississippi
The Mississippi Gulf Coast is a terraced deltaic plain with a fairly steep slope that
reaches eight feet per mile in some areas. The Pascagoula and Pearl Rivers, with
drainage areas of 24,346 km2 and 22,533 km2 (9,400 and 8,700 mi2) respectively, have
an average discharge into Mississippi Sound of 430 m3/second and 365 m3/second
(15,200 and 12,900 ft3/second), respectively. The Biloxi, Jourdan, and Wolf Rivers,
Bayou Bernard, and numerous other smaller streams contribute to a total estimate
of 50,764 km2 (19,600 mi2) of drainage area and an average discharge of 884
m3/second (31,220 ft3/second). Additional freshwater enters the Sound from the
Pontchartrain-Lake Borgne drainage to the West and Mobile Bay to the East.
Mississippi Sound itself is an elongated, relatively shallow body of water separated
from the Gulf of Mexico by a series of barrier islands. Four estuarine areas adjoin
the Sound, creating a complex area that defies any clear-cut hydrological
classification. The salinity gradient across Mississippi Sound and through the
estuaries decreases from averages above 33 ppt at the islands to freshwater in the
nearshore zone. A salinity decrease is also evident as one proceeds from east to
west, most likely the result of increased freshwater inflows in the western Sound. A
variety of vertical salinity gradients are evident in the Sound as well. Most typically,
bottom salinity is higher than that of the surface; relatively sharp salinity interfaces
may occur in some channels with rises in excess of 10 ppt occurring within a five
foot increase in depth.
The marshes that surround each of the major estuarine areas possess a very similar
flora. Most of the nearly 26,306 hectares (65,000 acres) of coastal mainland marsh is
dominated by Juncus roemerianus. Spartina alterniflora, Spartina patens, and Scirpus
oleyi are the major components of the saline marsh. Organic production in these
marshes, by higher vascular plants alone, is estimated at 2.7 billion kg (3 million tons)
annually, with a standing crop of approximately 2.7 billion kg (3 million tons). In
addition to emergent coastal marshes, Mississippi Sound also harbors patchy areas of
submergent seagrass beds, particularly along the northern shores of the barrier
islands.
Freshwater inflows from the major river systems and their associated sediments
maintain deposits of organic materials that extend from the mainland well into the
Sound, especially near the entrances to the major river systems. These organic
deposits are over sand which is exposed near the barrier islands and, in some cases,
includes shell fragments. As a result, Mississippi Sound and the adjacent inland
waters provide a diversity of plant and animal habitat.
This habitat supports a sport and commercial fishery that has played an important
role in the development of the Mississippi Gulf Coast. It has been estimated thai-
some 98 percent of the species that comprise the state's commercial landings are
estuarine-dependent in nature (Cooperative Gulf of Mexico Estuarine Inventory
and Study, Mississippi). The long-term viability of these fisheries is inextricably
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Freshwater Inflow in the Gulf of Mexico
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linked to the overall health of the estuarine system and the maintenance of the
freshwater inflows on which it depends.
Significant changes in freshwater inflows and fisheries production beyond a period
of four or five decades are difficult to determine. However, tarpon, once widely
caught in state waters according to historical accounts, have virtually disappeared; a
native strain of striped bass ceased to exist in the late 1940s. Prudent management of
Mississippi's freshwater resources may prevent additional losses in the future.
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Texas
The Texas coastal zone is oriented on a northeast-to-southwest arc of coastline on
the northwestern Gulf of Mexico. It extends almost 600 km (372 mi) along a nearly
continuous chain of barrier islands from Louisiana to the Mexico border, behind
which lies one of the most extensive estuarine systems in the U.S. Its watershed
encompasses approximately 500,000 km2 (193,000 mi2) of Texas, Louisiana, and New
Mexico, as well as northern Mexico (Orlando, et al, 1993). These systems comprise
more than 5,500 km2 (2,123 mi2) of open water and are bordered by tidal marshes
and mud-sand flats (Orlando, et al., 1993). While all of the estuaries are
hydrodynamically coupled in varying degrees, it is useful to separate them into
individual systems for detailed study and characterization (see Figure 2.5).
FIgur* 2.6
Coastal Zone of Texas Showing Major Estuarine
Systems
TEXAS
SABINE-NECHES
(Sabine Late)
TRINITY-SAN JACINTO
(GaKraston Bay)
LAVACA-COLORAOO
(Maugorda Bay)
GUADALUPE
(San Antonio Bay)
MISSION ARANSAS
(Aran&as Bay)
OUISIANA
BRAZOS-SAN BERNARD
(Brazos Rhw)
GULF OF MEXICO
MEXICO
(Source: USDOC, 1991 a)
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Texas coastal plains estuaries typically include wetlands and open waters in which
nutrients from river inflows, adjacent land runoff, and the sea support a productive
community of plants and animals. Texas bays and estuaries cover over 1.05 million
hectares (2.6 million acres) of land and provide over 2.4 million kg (10 million
pounds) of sport fish and approximately 36.3 million kg (80 million pounds) of
shrimp each year (Powell, 1991).
Freshwater Inflow. Year-to-year variability in freshwater input to Texas estuaries is
great, responding to the large-scale climate fluctuations which produce periods of
flooding and drought (USDOC, 1991a). The seasonal pattern of runoff tracks the
pattern for precipitation. For most of the coast, the spring is the high-flow season
and the summer is the low-flow season. In some years, the high-flow period is
pronounced and lengthy; but in other years, it may be completely absent. Although
river discharges in the low-flow period are less variable than those in the high-flow
period, annual variability does occur. In some years, the low-flow period is
shortened or eliminated by unusual runoff; in other years, it is prolonged.
Because river flow in Texas is governed by storm generated surface runoff, it is
highly variable and rivers exhibit large, sudden excursions in flow. The greater
frequency and intensity of precipitation-producing events in the watersheds of the
upper coast, along with the detention created by reservoirs, lead to considerable
overlap in the individual storm pulses (USDOC, 1991a). Hence, the freshwater
inflow hydrography in the upper coast estuaries is typically manifested as a seasonal
surge in runoff of several weeks to a few months in duration (USDOC, 1991a).
Further south, the runoff pulses become more isolated in time and the spring
inflow appears as a series of nearly discrete flood pulses. The monthly and seasonal
cumulative variation in freshwater inflow produces the most dramatic changes in
bay-wide salinity patterns in most Texas estuaries.
On the average, 29 million acre-feet of water per year flow into the bay and estuarine
systems in Texas (Powell, 1991). However, almost 75 percent of that amount occurs
in the two most eastern systems, the Sabine-Neches and the Trinity-San Jacinto.
The rainfall in Texas ranges from over 55 inches in eastern areas to less than ten
inches in western extremes. In addition, the Laguna Madre system in Texas is one
of only four hypersaline systems in the world (Powell, 1991).
Salinity Characteristics of Texas Estuaries. (USDOC, 1991a) The salinity structure
in Texas estuaries is determined primarily by hydrodynamic mechanisms which are
governed by the interaction of marine and terrestrial influences. Freshwater
plumes from the rivers that discharge into the northwestern Gulf of Mexico reduce
salinities of nearshore Gulf waters, especially in May and October (Cochrane and
Kelly, 1986). The degree to which salinities in Texas estuaries are affected by these
low salinity waters depends on their proximity to major river plumes and to the
year-to-year variability in river discharges, especially those of the Atchafalaya and
Mississippi Rivers.
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
Except for the Brazos-San Bernard which is essentially riverine, the eight estuaries
that were studied exhibit a similar geomorphology. These estuaries are lagoonal
embayments which are broad and shallow and are largely isolated from the Gulf of
Mexico, exchanging only through narrow inlets. Their large surface areas and
shallow depths make the estuaries extremely responsive to winds. Tidal influences
are negligible and are further attenuated by the narrow inlets that characterize this
region.
Despite these gross similarities, Texas estuaries exhibit a wide range in hydrographic
structure which, in turn, solicits a range of salinity response. However, the
principal controls on salinity were found to be similar for certain systems.
In general, the seasonally-dominated salinity structure of the north coast estuaries is
replaced by the event-driven structure of the mid-coast and lower coast systems.
Variability is related to the volume and timing of freshwater to the system. A more
variable salinity regime exists within the northern systems due to the presence of a
significant and continuous freshwater source. In contrast, freshwater input to the
lower coast estuaries is sporadic so that variability is generally associated with the
occurrence of a significant (low frequency) hydrologic event. The Matagorda and
Aransas systems are transitional, exhibiting the characteristics of two groups.
Upper Coast Estuaries (Sablne. Galveston. Brazos-San Bernard, and Matagorda). The salinity
structure within these estuaries is dominated by a strong seasonal freshwater signal.
On average, the volume of freshwater that enters these systems during the high-
flow period is three times greater than during the low-flow period. This produces a
seasonal difference in average salinities of 5 ppt. Within these estuaries, the
interaction zone between freshwater and Gulf water (i.e., the area exhibiting the
strongest salinity gradient and, therefore, greatest variability) shifts due to changes
in river discharge. As freshwater inflow decreases, Gulf waters intrude further
landward providing greater stability of lower estuarine salinities (i.e., dominated by
the Gulf). At the same time, upper bay areas begin to experience instabilities as the
zone of interaction is shifted landward.
Superimposed on this seasonal signal is the influence of meteorologically-induced
transport and mixing. The frequent occurrence of cold frontal passages during the
winter can account for as much as 50 percent removal of bay waters within a period
of a few days. These frontal movements are a principal source of flushing and
salinity variability as Gulf and estuarine waters exchange. Prevailing southeasterly
winds are, to a lesser degree, a contributing factor to salinity variability and act to
internally mix waters by the formation of large circulation gyres, wind waves, and
shear dispersion between adjacent water masses of varying depth.
Finally, the relatively free connection between these estuaries and the Gulf
(enhanced by the existence of ship channels) provides increased access to Gulf waters
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
as density-induced currents act to convey and entrain more saline coastal waters.
These coastal waters exhibit their own salinity variability due to the advection of
river plumes along the shelf from Louisiana.
Mid-Coast Estuaries fMatagorda. 'San Antonio, and Aransas^. The salinity Structure within
these estuaries is not dominated by a seasonal freshwater inflow signal. The
principal time scale over which salinity varies ranges from weeks to months and is
associated with isolated freshwater inflow events which can occur throughout the
year. The effect on salinity is limited to the upper bay regions (e.g., Lavaca Bay, San
Antonio Bay, and Copano Bay) which are somewhat geographically confined and
distinguishable from the lower lagoonal reaches adjacent to the chain of barrier
islands.
This part of the Texas coast is prone to prolonged periods of drought which, in turn,
contribute to the year-to-year variability of salinity. This, in conjunction with
limited Gulf access, tends to dampen salinity variability when compared to upper
coast systems. These bays tend to have a longer "memory" (i.e., less intense
flushing) of the freshwater event. In Copano Bay, for instance, short-duration
freshets can depress salinities for several months. In contrast, the lower lagoonal
reaches of these systems tend to be responsive to meteorological mixing and inter-
estuarine exchanges which are dictated by the behavior of prevailing winds.
Lower Coast Estuaries fAransas. Corpus Christi. and Laguna Madre^. The salinity structure of
these estuaries is determined by isolated freshwater pulses rather than seasonal
discharge. When compared to the upper and mid-coast estuaries, these watersheds
are more arid, frontal passages are less frequent, and inflows are lower. As a result,
the salinity structure of these systems tends to be more stable. The reduced
influence of freshwater allows other forcing mechanisms to become relatively more
important. Evaporation is a significant factor that affects seasonal changes in
salinity. Tides are important as a means of internal mixing and may actually reduce
salinities when estuaries become hypersaline. Wind dictates inter-estuarine
exchanges.
However, the internal gradients of salinity are generally small and exhibit a
persistent stability. This behavior is only interrupted by the occasional freshet
which may dramatically impact salinity for several weeks. Only under this
condition are density currents an important mechanism for salinity intrusion.
Impacts of Alterations in Freshwater Inflows. There is concern that modifications
of Texas estuaries, including creation of navigational channels and alteration of
inflows, have caused, or could cause, a reduction in estuarine populations of fish
and wildlife. Construction of the Intracoastal Waterway may have caused the
Laguna Madre to become less saline and the Chenier Plains Marshes near Sabine
Lake to become more saline. Alteration of seasonal inflows in the Sabine River due
to Toledo Bend Reservoir may have sharply reduced shrimp production in the
Sabine Lake area. Striped Bass (Morone saxatilis) no longer exist in Texas estuaries
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Freshwater Inflow in the Gulf of Mexico
Chapter 2
in harvestable quantities (Texas Water Development Board). Snook (Centropomis
undecimalis) have also dramatically declined in abundance. Oyster (Crassostrea
virginica) landings from Nueces Bay have essentially disappeared, and extensive
dredging of oyster beds for shell during the period 1941 through 1967 reduced
available substrate for oyster populations in many Texas estuaries (Texas Water
Development Board). In addition, numbers of brown pelicans (Pelecanus
occidentalis), Eskimo curlews (Numenius borealis), piping plovers (Charadrius
melodus), and American alligators (Alligator mississippiensis) also have declined
over the long-term. Recently, however, there have been significant increases in the
numbers of brown pelicans, whooping cranes (Grus americana), and American
alligators (Texas Water Development Board).
The reasons for the reductions in these populations are not always clear.
Overfishing, habitat destruction or alteration, and pollution have occurred and are
undoubtedly contributing factors. Alteration of seasonal freshwater inflows also has
had some influence, and there is concern about the quantity of inflows reaching the
estuaries. Even though there have been changes in the abundance of some species,
the available data suggest that Texas estuaries still retain much of their historical
composition and productivity (Texas Water Development Board).
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
Case Studios on Trends In Streamflow, Precipitation &
Surface Water Withdrawals & Effects of Reservoirs
•ndSIad*, 1»»2)
The four basins that were chosen for study are the Apalachicola River basin in
Georgia, Alabama, and Florida; the Pearl River basin in Mississippi and Louisiana;
and the Trinity River and Nueces River basins in Texas (see Figure 2.6). These
basins were chosen because of their geographic distribution and diversity in
hydrology, climate, land use, and extent of development. A variety of factors affect
streamflow in these four basins.
Temporal trends in streamflow were compared with trends in associated
precipitation for the main channels and tributaries of four major rivers
(Apalachicola, Pearl, Trinity, Nueces). Both long-term and short-term trends were
identified for selected streamflow gages with at least forty years of record. Trends
were determined for annual mean discharges, annual minimum and maximum
daily mean discharges, and associated annual mean precipitation.
Case Study Trends. Long-term trends indicate no temporal change in annual mean
and annual maximum discharges to the Gulf of Mexico from the Apalachicola
River basin. Annual mean and annual maximum discharges to the Gulf increased
temporally from the Pearl River basin and decreased from the Trinity River and
Nueces River basins. Annual minimum discharges to the Gulf increased in all four
of the basins studied. The annual mean precipitation associated with the most
downstream gage also increased temporally during the periods of record studied in
all four of the basins. The short-term trends in streamflow generally corresponded
to the trends in associated precipitation for each gage. For some gages in the Trinity
River basin, short-term trends in annual minimum discharge increased, and short-
term trends in annual maximum discharge decreased.
Total reported surface water withdrawals increased more than fourfold in the
Trinity River basin since 1940. Present surface water withdrawals from the Trinity
River basin represent about one-fourth of the mean streamflow near the mouth.
Total withdrawals increased more than eightfold in the Nueces River basin since
1940. Present surface water withdrawals from the Nueces River basin represent
about one-third of the mean streamflow near the mouth.
Effects of selected reservoirs on streamflow in the four basins also were studied.
Predicted peak discharges downstream from reservoirs on the upper reaches of the
Apalachicola and Trinity Rivers were as much as 75 percent less for the fifty year
flood after the reservoirs were constructed. Predicted peak discharges into the Gulf
from the Apalachicola River were about 23 percent less for the fifty year flood after
reservoir construction. Although one large reservoir was built on the Pearl River
and many reservoirs have been built on the Trinity River and its tributaries, the
findings indicated that peak discharges into the Gulf of Mexico from the Pearl and
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
Figure 2.6
Location of the Apalachicola River, Pearl River,
Trinity River & Nueces River Basins
(Source: Greene and Slade, 1992)
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Freshwater Inflow In the Gulf of Mexico
Chapter 2
Trinity Rivers were not affected during the past fifty years. However, statistical
analyses of the precipitation streamflow relations indicated that annual mean
discharges were reduced following construction of the most downstream reservoirs
on the Apalachicola and Trinity Rivers. A water budget analysis estimated that the
mean discharge to the Gulf from the Nueces River was reduced by about 41 percent
as a result of filling and evaporation at Choke Canyon Reservoir.
The trends identified in this study have important implications for the estuarine
ecosystems that receive freshwater inflows from each of these basins. Sediment and
nutrient inflows to bays and estuaries depend on streamflow. The findings of this
study suggest that the pattern and quantity of streamflow from the Apalachicola,
Pearl, Trinity, and Nueces River basins have changed during the period of record
studied. Many of these temporal changes can'be attributed to human activities in
the basins.
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Froshwat&r Inflow in the Gulf of Mexico
Chapter 2
Conclusion
Estuaries are by definition dependent upon certain levels of freshwater inflow.
Water must be provided in the proper amount, location, and timing for estuaries to
be productive. All other things being equal, estuaries with large inflows of
freshwater are more productive than estuaries with less flow. A given estuary is
more productive in and after wet years than dry ones.
Detrimental changes have been occurring in the amount, timing, and location of
freshwater inflow to estuaries. Such changes are caused by impoundments,
diversions of water for consumptive use, flood control, hydropower, navigation
projects, and other public works projects in rivers and watersheds. Inflow
alterations affect the delivery of sediment and nutrients and cause significant
changes in estuarine circulation and salinity.
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Federal & State Framework
Chapter 3
3 FEDERAL & STATE FRAMEWORK FOR ADDRESSING
FRESHWATER INFLOWS
While no single agency or program has responsibility for freshwater inflows or is
addressing this issue specifically, there is a broader legal and institutional
framework currently in place in the Gulf of Mexico that can address freshwater
inflow issues. For a description of this framework, see Appendix A. Action Items 9
and 10 in Chapter 4 of this document address the need for additional policies and
programs to address freshwater inflow issues.
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Chapter 4
4 THE UNFINISHED AGENDA --
Both Current Commitments & Uncommitted Activities
Goal
This Freshwater Inflow Action Agenda for the Gulf of Mexico sets forth a
framework for conserving, protecting, and restoring Gulf waters that will minimize
freshwater inflow concerns. The Gulf of Mexico Program has established the
following long-term goal for addressing freshwater inflow concerns:
Q Protect, preserve, restore, and, where feasible, enhance the freshwater
inflow to the Gulf of Mexico and the associated bays and estuaries for the
purpose of maintaining the ecological health and integrity of those
systems.
For the purposes of this Action Agenda, "freshwater" includes surface water, ground
water, springs, and precipitation. Also, where the term "sediment" is used, it refers
to the "sediment regime" (erosion, deposition, transport).
Objectives & Action Items
Four types of activity have been designed to meet the goal: 1) Policy, Planning &
Implementation, 2) Research, 3) Monitoring & Assessment, and 4) Public Education
& Outreach. Specific objectives and action items are grouped according to these
areas (see Index of Freshwater Inflow Objectives & Action Items).
Objectives are the specific, short-term targets for attaining the goals. Each
objective is followed by action items that describe specific tasks to meet the goals
and objectives for the Freshwater Inflow Action Agenda. Each action item is
presented under an appropriate objective. Some action items are cross
referenced to other action items by a "-»" sign in the left hand column. This
signals a close relationship among those actions and a need for coordination.
Lead. The Freshwater Inflow Committee has identified a lead agency for each
action item. A proposed action item may involve the execution of legislative or
regulatory authorities or programmatic initiatives which derive from these
authorities. In other cases, a proposed action item may involve the facilitation
or coordination of activities among several agencies or organizations. In these
cases, and where there is no clear legislative authority involved, the "lead" could
be the agency or organization which expresses an interest in taking on the task
during Gulf of Mexico Program Issue Committee deliberations, the action
planning workshop or public comment period, or, in the Issue Committee's
judgment, is best able to guide multiple parties in carrying out the activity. This
does not necessarily mean that the agency has agreed to carry out the activity or
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The Unfinished Agenda
Chapter 4
that the agency has the necessary funding. The Freshwater Inflow Committee
understands these action items will require commitments by agencies and
organizations that are dependent on budget decisions. However, the Issue
Committee members hope this document provides the rationale and support for
such commitments and that future iterations of this document will include
additional specific commitments.
Initiation Date. The date indicated represents a determination by the Issue
Committee of the most realistic initiation date for the action item. As lead
agencies begin implementation planning for specific action items, these
initiation dates may change due to resource availability and prioritization within
the individual agencies.
The Gulf of Mexico Program recognizes the need to identify indicators of
environmental progress relative to this Action Agenda for freshwater inflow. Many
of the action items specified in Chapter 4 of this document will aid the Program in
developing a baseline for measuring success in the future. For the time being,
however, acceptance and completion of action items specified in this Action Agenda
will be considered a measure of success. As future Action Agendas are written and
current action items are completed, new action items will be developed to better
measure environmental progress.. The Gulf of Mexico Program will coordinate
among the eight Gulf of Mexico Program Issue Committees to eliminate overlap
and duplication of efforts, as well as to integrate goals and activities across
environmental issue areas.
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Chapter 4
Index of Freshwater Inflow Objectives & Action Items
Policy. Planning & Implementation
Objective: Develop a process for assessing the range of freshwater needs for estuarine and coastal waters of
the Gulf of Mexico and identify the quantity and quality of freshwater necessary to meet those needs.
Action Item 1: Freshwater Predictive Tools for the Gulf of Mexico
Action Item 2: Use of International Literature to Increase Understanding of Freshwater Inflows to
Gulf of Mexico Coastal Systems
Action Item 3: Gulfwide Forum for Assessment of Freshwater Needs
Objective: Identify and evaluate Gulf of Mexico estuaries with freshwater inflow issues and select appropriate
estuaries for management attention.
Action Item 4: Identification of Gulf of Mexico Estuaries & Coastal Waters of Concern
Action Item 5: Comprehensive Plans for Selected Gulf of Mexico Estuaries
Action Item 6: Freshwater Inflow Demonstration Program for the Gulf of Mexico
Action Item 7: Freshwater Inflow Sediment Management in the Gulf of Mexico
Objective: Develop a coordinated Gulfwide strategy to provide adequate freshwater inflows to the estuarine
and coastal waters of the Gulf of Mexico.
Action Item 8: Integrated Mississippi River Management Plan
Action Item 9: Freshwater Program & Policy Inventory
Action Item 10: Freshwater Program & Policy Recommendations & Case Studies
Action Item 11: "Partnership for Action" Among the U.S., Mexico & Caribbean
Objective: Develop policy alternatives on the allocation of water among Gulf of Mexico estuaries.
Action Item 12: Integrative Decision Methodology for Water Allocations
Action Item 13: Gulf of Mexico Management Options for Water Flows
Objective: Promote the watershed approach in national policy.
Action Item 14: Integration of Gulf of Mexico Program Committee Activities & Consistent Mapping
Action Item 1S: Accounting for Freshwater Needs in Gulf of Mexico Development Plans & BMPs
Action Item 16: National Watershed Initiative Support
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Chapter 4
Index of Freshwater Inflow Objectives & Action Items (continued)
Research
Objective: Conduct research to improve the understanding of relationships among freshwater inflows, salinity
patterns, nutrient delivery and uptake, sediment regimes, circulation and flushing times, estuarine productivity,
and habitat (with an emphasis on major representative river systems) in the Gulf of Mexico.
Action Item 17: Science Inventory Related to Freshwater Inflows
Action Item 18: Methodologies for Mapping Structural Habitats of Coastal Systems'
Action Item 19: Relationship Between Freshwater Inflows & Productive Habitat in the Gulf of
Mexico
Action Item 2O: Inflow Effects on Salinity Gradients & Organisms within the Gulf of Mexico
Action Item 21: Surface Water System Augmentation & Salt Water Intrusion Model
Action Item 22: Quantification of Freshwater Linkages & Relationships in the Gulf of Mexico
Action Item 23: Relationship Between Precipitation/Runoff & Input to Ground Water in the Gulf of
Mexico
Action Item 24: Gulf of Mexico Interagency/Interstate Freshwater Research Program
Action Item 25: Tools for Gulf of Mexico Managers to Utilize Freshwater Inflow Research
Objective: Conduct research on the cumulative impacts of alterations on freshwater inflows to the Gulf of
Mexico. .,
Action Item 26: Relationship Between Gulf of Mexico Anoxic Events Near River Outlets & Upstream
Flow Alterations
Action Item 27: Relationship Between Gaged Flow & Actual Flow to Gulf of Mexico Coastal Systems
Action Item 28: Precipitation Gauges in Gulf of Mexico Coastal Wetlands
•Action Item 29: Impacts of Sediment Delivered to Gulf of Mexico Coastal Systems
Action Item 30: Review of Models & Technology to Compare Patterns of Freshwater Inflow, Salinity,
Nutrients & Sediment Regimes in the Gulf of Mexico
Objective: Conduct research on population and economic projections in the Gulf of Mexico related to
freshwater needs and flows and related socio-political issues.
Action Item 31: Effects of Economic Growth on Freshwater Inflows to Gulf of Mexico Coastal Systems
Action Item 32: Use of Reclaimed Water to Replace Flow Losses to Gulf of Mexico Coastal Systems
Action Item 33: Gulf of Mexico Water Conservation Alternatives Research
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Chapter 4
Index of Freshwater Inflow Objectives & Action Items (continued)
Monitoring & Assessment
Objective: Inventory all available data and identify data gaps relating to water quality and quantity, water use
actors, and effects of freshwater inflow on Gulf of Mexico estuarine productivity-including salinity patterns,
nutrient delivery and uptake, sediment regimes, land use and land use changes, biological parameters,
;eomorphology, and types of freshwater inflow (e.g., surface water, ground water, and other sources).
Action Item 34: Gulfwide Priorities for Data Acquisition & Collection
Action Item 36: Inventory of Available Data & Information Sources Relevant to Gulf of Mexico
Freshwater Inflows
Action Item 36: Acquisition, Quality Assurance & Synthesis of Gulf of Mexico Freshwater Inflow
Data
Action Item 37: Minimum Data Set for Gulf of Mexico Estuaries or Basins
Action Item 38: Feedback Loop for Gulf of Mexico Freshwater Data Collection
Objective: Assess trends in freshwater inflows to the Gulf of Mexico.
Action Item 39: Identification of Data Needed for Freshwater Inflow Trend Assessment in the Gulf
of Mexico
Action Item 4O: Inventory of Major Gulf of Mexico Watershed Modifications
Action Item 41: Estimation of Naturalized Flows & Variability in the Gulf of Mexico
Action Item 42: Climatological Trends in the Gulf of Mexico
Action Item 43: Meteorological Trends in the Gulf of Mexico
Objective: Identify and evaluate causes of change in freshwater inflow quantity and quality relative to location,
volume, and timing of change within an estuary or segment in the Gulf of Mexico.
Action Item 44: Identification & Ranking of Contributions to Causes of Freshwater Inflow Change in
the Gulf of Mexico
Action Item 46: Future Agricultural/Industrial Management Practices Affecting Runoff &
Hydrogeologic Patterns in the Gulf of Mexico
Action Item 46: Anthropogenic Activities Affecting Seasonal Runoff Patterns in the Gulf of Mexico
Action Item 47: Groundwater Inputs to Freshwater in Gulf of Mexico Estuaries
Action Item 48: Long-Term Climatic Effects on Surface Waters & Freshwater Inflows to the Gulf of
Mexico
Objective: Determine Gulf of Mexico estuarine resource-based salinity requirements based on existing
knowledge and working hypotheses (inventory what has been done and identify what needs to be done for major
representative ecosystems).
Action Item 49: Salinity Requirements for Seagrasses in the Gulf of Mexico
Action Item 60: Salinity Requirements for Fish & Invertebrates in the Gulf of Mexico
Action Item 61: Natural Rate of Change in Gulfwide Salinity Based on Tidal Scale
Action Item 62: Gulf of-Mexico Estuarine Flushing Times
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Chapter 4
Index of Freshwater Inflow Objectives & Action Items (continued)
Monitoring & Assessment (continued)
Objective: Identify linkages and assess relationships among freshwater inflows, salinity patterns, nutrient
delivery and uptake, sediment regimes, estuarine productivity, other water quality parameters, and the adjacent
Gulf of Mexico.
Action Item 63: Criteria & Process for Prioritizing Gulf of Mexico Freshwater Inflow Linkages &
Relationships for Evaluation
Action Item 54: Methodology to Identify Freshwater Inflow Relationships & Linkages Within a
Typical Estuary for Each Gulf State
Action Item 55: Expansion of State Freshwater Inflow Methodologies to Other Basins/Estuaries
Throughout the Gulf of Mexico
Action Item 56: Gulfwide Characterization Workshops for Freshwater Inflow Concerns
Objective: Develop a Gulfwide monitoring program to assess the effectiveness of freshwater management
actions on an estuary specific (or estuary class) basis.
Action Item 57: Management Objectives for Freshwater Monitoring Program Design for Gulf of
Mexico Estuaries
Action Item 58: Assessment of NAS Monitoring Approach for Gulf of Mexico Use
Action Item 59: Development of Gulf of Mexico Monitoring Standards & Modification of Monitoring
Plan Based on Planned Hydrologic Changes
Action Item 60: Gulf of Mexico Protocols for Biological Parameters & Basin Relationships
Action Item 61: Freshwater Monitoring Cost/Benefit Study for the Gulf of Mexico
Action Item 62: Gulf of Mexico Monitoring Coordination & Facilitation
Action Item 63: Gulfwide GIS & Data Management System
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Chapter 4
Index of Freshwater Inflow Objectives & Action Items (continued)
Public Education & Outreach
Objective: Promote the basin-wide public awareness of ecological, economic, and health impacts associated
with alterations of freshwater inflows to estuarine systems and the cumulative role of those estuaries for sustaining
the health of the Gulf of Mexico.
Action Item 64: Process to Identify Education & Outreach Needs for Gulf of Mexico Freshwater
Inflows
Action Item 65: Technical Overview Document to Describe Gulf of Mexico Freshwater Inflow Issues
Action Item 66: Existing Publications That Reach the Gulf of Mexico Public on Freshwater Inflow
Issues
Action Item 67: Freshwater Inflow Curriculum
Action Item 68: Freshwater Inflow Workshops for Educators in the Gulf of Mexico Region
Action Item 69: Gulf of Mexico Freshwater Inflow Media Kits
Action Item 7O: Gulf of Mexico Freshwater Inflow Public Broadcasting Program
Action Item 71: Gulf of Mexico Freshwater Inflow Information Portfolio
Action Item 72: Gulf of Mexico Freshwater Inflow Clearinghouse
Action Item 73: Articles on Freshwater Inflow Issues in the Gulf of Mexico
Action Item 74: Gulfwide Water Resources & Fisheries Management Integration
Action Item 75: Establishment of Land Owners Associations in the Gulf of Mexico Region
Action Item 76: Awards Program for Gulf of Mexico Freshwater Inflow Issues
Action Item 77: Gulf of Mexico Urban Outreach Programs
Action Item 78: Gulf of Mexico Model Landscape Program
Objective: Promote the basin-wide awareness of federal, state, and local government officials and decision-
makers of the ecological, economic, and health impacts associated with alterations of freshwater inflows to
estuarine systems and the cumulative role of those estuaries for sustaining the health of the Gulf of Mexico.
Action Item 79: Existing Publications That Reach Gulf of Mexico Officials on Freshwater Inflow
Issues
Action Item 80: Technical Papers on Gulf of Mexico Freshwater Inflow
Action Item 81: Gulfwide Seminars on Freshwater Inflow Issues
Action Item 82: Gulfwide Road Shows on Freshwater Inflow Issues
Action Item 83: Videos on Freshwater Inflow Issues in the Gulf of Mexico
Action Item 84: Information to Gulf of Mexico Legal Professions About Freshwater Inflow Issues
Objective: Promote basin-wide public involvement to address the ecological, economic, and health impacts
associated with alterations of freshwater inflows to estuarine systems and the cumulative role of those estuaries for
sustaining the health of the Gulf of Mexico;
Action Item 85: Endorsement of Gulfwide Public Involvement Activities Related to Freshwater Inflow
Issues
Action Item 86: Development of "What I Can Do" Lists to Address Freshwater Inflow Issues
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Chapter 4
Policy, Planning & Implementation
No single agency or program has responsibility for freshwater inflows. This fact
heightens the need for an integrated, coordinated Gulfwide approach to freshwater
inflow concerns. The development of compatible policies or processes among
federal agencies and Gulf Coast States is crucial in order to reduce freshwater inflow
concerns in the Gulf of Mexico.
Specific objectives and action items follow:
Objective:
Develop a process for assessing the range of freshwater
needs for estuarine and coastal waters of the Gulf of
Mexico and identify the quantity and quality of
freshwater necessary to meet those needs.
Action Item 1 • Freshwater Predictive Tools for the Gulf of Mexico
Develop appropriate "predictive tools" to support the Gulf of
Mexico freshwater assessment process for both present
conditions and future time periods.
Lead Agency: National Oceanic & Atmospheric
Administration, U.S. Environmental Protection Agency, and
Gulf State resource agencies.
Initiation Date: 1996
2, 53, 56, €>3
Action Item 2
Use of International Literature to Increase Understanding of
Freshwater Inflows to Gulf of Mexico Coastal Systems
Review and analyze information from the international
literature to increase understanding of Gulf of Mexico coastal
systems regarding freshwater inflows and the potential to
protect these systems from losses.
Lead: National Oceanic & Atmospheric Administration, U.S.
Environmental Protection Agency, and Gulf State resource
agencies, in coordination with Gulf of Mexico Program.
Initiation Date: 1994
1, 10
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Th& Unfinished Agenda
Chapter 4
Action It*m 3 - Gulfwide Forum for Assessment of Freshwater Needs
Conduct a forum to share assessment ideas and approaches
among the five Gulf States. This should include a review of
the various salinity, nutrient, and sediment loading regimes
needed to maintain an ecologically and economically sound
environment in the receiving estuary systems, as well as
biological indicators, societal values, and a framework for
decision making.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1995
-» 5 6
Objective:
Identify and evaluate Gulf of Mexico estuaries with
freshwater inflow issues and select appropriate
estuaries for management attention.
Action Item 4 - Identification of Gulf of Mexico Estuaries & Coastal Waters of
Concern
Develop a consensus approach across the five Gulf States for
defining "threatened" estuaries which will be used to drive the
prioritization, and corresponding selection, of estuaries for
future planning efforts. Criteria could include such factors as
the severity of existing problems, cultural factors, expected near
term anthropogenic changes, as well as infrastructure available
to solve problems and the ability to achieve success. In
addition, the significance and impact of smaller coastal basin
estuaries should be addressed.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1995
-» 4O, 56
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Chapter 4
Aetlen Horn 6 - Comprehensive Plans for Selected Gulf of Mexico Estuaries
Develop "comprehensive plans" for selected estuaries in the
Gulf of Mexico starting with one in each of the five Gulf States
and continuing using the priority listing generated in Action
Item 4. Planning goals and components of the comprehensive
plan will be developed by a five state working group. It is
anticipated that the plans will include a documentation of
needs, the development of resource-based water quality criteria,
appropriate regulatory structures, and other requirements for
meeting freshwater needs, as well as identification of
restoration opportunities. Where appropriate, these plans will
build on work completed (or underway) by the National
Estuary Programs and Coastal Wetlands Planning, Protection &
Restoration Act projects.
Lead: Appropriate Gulf State agencies.
Initiation Date:: 1996
-» 4
Action Itom 6 • Freshwater inflow Demonstration Program for the Gulf of Mexico
Develop and implement one or more demonstration programs
that focus on the "how to's" for ensuring the adequacy of
freshwater to estuaries within the Gulf of Mexico. Provide
technology transfer across the five Gulf States on a menu of
successful approaches that could be adopted incrementally.
Where appropriate, these plans will build on work completed
(or underway) by the National Estuary Programs and Coastal
Wetlands Planning, Protection & Restoration Act projects.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1997
Action Item 7 - Freshwater Inflow Sediment Management in the Gulf of Mexico
Identify areas within the Gulf of Mexico that need sediment
enrichment, for the maintenance and creation of wetlands, and
promote the management of sediments to increase loadings in
these areas.
Lead: Appropriate Gulf State agencies, in coordination with
Gulf of Mexico Program—Freshwater Inflow Committee and
Habitat Degradation Committee.
Initiation Date: 1997
-» 6
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Chapter 4
Objective:
Develop a coordinated Gulfwide strategy to provide
adequate freshwater inflows to the estuarine and
coastal waters of the Gulf of Mexico.
Action It«m 8 • Integrated Mississippi River Management Plan
Develop an integrated management plan for the Mississippi
River which focuses on the Delta. All appropriate Gulf of
Mexico Program Issue Committees, including Habitat
Degradation, Nutrient Enrichment, and Coastal & Shoreline
Erosion, will participate in scoping the components of the plan.
The freshwater focus will be on sediment transport.
Lead; Gulf of Mexico Program.
Initiation Date: 1998
Action Item 9 - Freshwater Program & Policy Inventory
Develop a comprehensive inventory of national, Gulf State,
and local programs and policies that address the sufficiency of
freshwater for estuaries. National programs should include
the U.S. Environmental Protection Agency nonpoint source
and NPDES storm water programs. •
Lead: U.S. Environmental Protection Agency, in coordination
with Gulf State agencies. '
Initiation Date: 1994
Action Item 1O - Freshwater Program & Policy Recommendations & Case Studies
Using the inventory developed in Action Item 9, conduct an
analysis of the strengths and weaknesses of current policies and
approaches addressing freshwater needs and make
recommendations to appropriate regulatory agencies to
promote consistency and coordination within the Gulf of
Mexico. Produce and distribute case studies of successful
approaches for addressing freshwater needs.
Lead; Gulf of Mexico Program.
Initiation Date: 1995
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Chapter 4
Action Horn 11 • "Partnership for Action" Among the U.S., Mexico & Caribbean
Develop a "Partnership for Action" document, similar to the
December 1992 Gulf of Mexico Program Partnership for Action,
to be signed by Presidents and senior policy officials. This
document should identify goals, challenges, and initiatives
(including technology transfer) related to freshwater inflow for
the Gulf of Mexico among the U.S., Mexico, and the Caribbean.
Lead: Gulf of Mexico Program.
Initiation Date: 1996
Objective:
Develop policy alternatives on the allocation of water
among Gulf of Mexico estuaries.
Action Item 12 - Integrative Decision Methodology for Water Allocations
Develop and/or identify an existing decision support
methodology which integrates all available and appropriate
information to support the allocation of water on a watershed
basis.
Lead: Gulf of Mexico Program, in coordination with Gulf State
resources agencies.
Initiation Date: 1995
Action Item 13 - Gulf of Mexico Management Options for Water Flows
Develop and make recommendations to the five Gulf States on
management options for water flow to the estuaries. This
could incorporate recommendations for interstate compacts.
Lead: Gulf of Mexico Program.
Initiation bate: 1996
1 2
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Chapter 4
Objective: Promote the watershed approach in national policy.
Action Item 14 - Integration of Gulf of Mexico Program Committee Activities &
Consistent Mapping
Work with all appropriate Gulf of Mexico Program
Committees to use consistent digitized basin maps for planning
and implementation activities and to integrate other activities
as appropriate.
Lead: Gulf of Mexico Program—Data & Information Transfer
Operations.
Initiation Date: 1994
Action Item 16
Accounting for Freshwater Needs in Gulf of Mexico Development
Plans & BMPs
Ensure that the freshwater needs of Gulf of Mexico estuaries
ecological and economic purposes are accounted for in water
development plans, land development plans, BMPs for
agriculture, and other factors that impact runoff.
for
Lead: Appropriate Gulf State agencies.
Initiation Date: 1996
-*• 5, 1O
Action Item 16 - National Watershed Initiative Support
Support national initiatives that advocate appropriate
watershed approaches.
Lead: Gulf of Mexico Program.
Initiation Date; Ongoing
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Chapter 4
Research
To adequately address Gulf of Mexico freshwater inflow concerns, more complete
knowledge is needed. Most research funds are administered by federal agencies or
state program offices in support of specific missions, with only limited funding
going to research that examines the cumulative effects of decisions on the ecosystem
as a whole. This action planning process provides the necessary mechanism to
enable the producers, consumers, and funders of research to agree on priorities. A
closer connection should be established between the research agenda of the scientific
community and the information needs of managers, regulators, and those involved
in decisions for the management of the Gulf of Mexico. Once a research agenda is
developed and implemented, the research results should be used to understand the
underlying processes and relationships and to support appropriate decisions
regarding management of Gulf waters.
Specific objectives and action items follow:
Objective:
Conduct research to improve the understanding of
relationships among freshwater inflows, salinity
patterns, nutrient delivery and uptake, sediment
regimes, circulation and flushing times, estuarine
productivity, and habitat (with an emphasis on major
representative river systems) in the Gulf of Mexico.
Action Hem 17 - Science Inventory Related to Freshwater Inflows
Inventory applicable scientific documentation to determine
information needs and data gaps related to freshwater inflows
in the Gulf of Mexico.
Lead: U.S. Geological Survey.
Initiation Date: 1995
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Chapter 4
Action Item 18 - Methodologies for Mapping Structural Habitats of Coastal
Systems
Research and evaluate the methods for mapping the structural
habitat of coastal systems. The objective is to be able to
determine the probability that a habitat is a valuable nursery.
Examine the present and past salinity and water quality
patterns at high quality locations in the Gulf of Mexico.
Emphasis should be placed on determining the most cost-
effective methods.
Lead: U.S. Fish & Wildlife Service, in coordination with
National Marine Fisheries Service and Gulf of Mexico
Program—Habitat Degradation Committee.
Initiation Date: 1995
Action Item 19 - Relationship Between Freshwater Inflows & Productive Habitat
in the Gulf of Mexico
Determine the relationships between freshwater inflows and
productive habitat on an estuary by estuary basis throughout
the Gulf of Mexico.
Lead: Gulf State resource agencies, in coordination with Gulf of
Mexico Program—Freshwater Inflow Committee and Habitat
Degradation Committee.
Initiation Date: 1996
1 8
Action Item 2O - Inflow Effects on Salinity Gradients & Organisms within the Gulf
of Mexico
Determine the effects of changes in the amounts and locations
of inflow on Gulf of Mexico estuarine salinity gradients and the
estuarine organisms that depend on these gradients.
Lead: U.S. Fish & Wildlife Service and National Marine
Fisheries Service.
Initiation Date: 1996
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Chapter 4
Action Item 21 - Surface Water System Augmentation & Salt Water Intrusion
Model
Develop a model to investigate: 1) the ecological benefits of
augmentation of surface water systems; and 2) the impacts of
associated changes in salinity patterns.
Lead; National Oceanic & Atmospheric Administration.
Initiation Date: 1997
2 O
Action Item 22
Quantification of Freshwater Linkages & Relationships In the Gulf of
Mexico
Conduct research and studies needed to quantify linkages and
relationships among Gulf of Mexico freshwater inflows,
salinity patterns, nutrient delivery and uptake, sediment
regimes, circulation and flushing times, estuarine productivity,
and habitat for estuarine resources, such as fish and shellfish
(with an emphasis on major representative river systems).
Also, quantify the relationship between seasonal freshwater
discharges to coastal systems and the life histories (abundance
and distribution) of estuarine living resources.
Lead: U.S. Fish & Wildlife Service, in coordination with Gulf
State resource agencies.
Initiation Date: 1995
3 O
Action Item 23 - Relationship Between Precipitation/Runoff & Input to Ground
Water in the Gulf of Mexico
Determine the relationship between precipitation/runoff and
input to ground water (base flow). Utilize both historic data and
other qualitative records to construct long-term records of
precipitation and runoff in the Gulf of Mexico.
Lead: U.S. Geological Survey.
Initiation Date: 1994
4 2
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Chapter 4
Action Item 24 - Gulf of Mexico Interagency/lnterstate Freshwater Research Program
Develop an integrated, interdisciplinary, and interagency
research program focusing on freshwater inflows, salinity, and
estuarine productivity. Utilize working hypotheses to frame
research programs and a multi-year agenda for the Gulf of
Mexico.
Lead: Gulf State resource agencies and Gulf of Mexico
Program—Freshwater Inflow Committee.
Initiation Date: 1994
49, SO, 51, 52
Action Item 25 - Tools for Gulf of Mexico Managers to Utilize Freshwater Inflow
Research
Develop tools to allow water, land, and living resource
managers within the Gulf of Mexico region to utilize
information developed from freshwater inflow research.
Lead: Gulf of Mexico Program—Data & Information Transfer
Operations.
Initiation Date: 1996
1, 3, 6, 36, 63
Objective:
Conduct research on the cumulative impacts of
alterations on freshwater inflows to the Gulf of Mexico.
Action Item 26 - Relationship Between Gulf of Mexico Anoxie Events Near River
Outlets & Upstream Flow Alterations
Investigate the possible relationship between anoxic events in
the area of river outlets in the Gulf of Mexico and the
manmade changes that have occurred in the water pathways of
the river. Initial investigations should concentrate on the
Mississippi River outlet and the anoxic events off the coast of
western Louisiana.
Lead: Louisiana Department of Natural Resources, in
coordination with Gulf of Mexico Program—Freshwater Inflow
Committee.
Initiation Date: 1995
-» 36, 63
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Chapter 4
Action Itom 27 • Relationship Between Gaged Flow & Actual Flow to Gulf of
Mexico Coastal Systems
Determine the relationship between gaged flows and the flow
actually reaching Gulf of Mexico coastal systems.
Lead; U.S. Geological Survey.
Initiation Date: 1994
Aeilen Item 28 • Precipitation Gauges in Gulf of Mexico Coastal Wetlands
Establish precipitation gauges in selected Gulf of Mexico coastal
wetlands to monitor contributing runoff to estuaries and other
parameters, such as atmospheric deposition. __^
Lead: National Oceanic & Atmospheric Administration--
National Weather Service.
Initiation Date: 1995
Aetlon Item 29
Impacts of Sediment Delivered to Gulf of Mexico Coastal
Systems
Research the impacts of the changing regime of sediment
delivery to Gulf of Mexico coastal systems.
Lead: Gulf State resource agencies (Bureau of Economic
Geology in Texas). •' - ' - '• . - -
Initiation Date: 1994
Action Item 3O
Review of Models & Technology to Compare Patterns of
Freshwater Inflow, Salinity, Nutrients & Sediment Regimes in
the Gulf of Mexico
Research existing watershed river and estuary models and
modeling technology to compare historic (pre-development)
and modern patterns of freshwater inflow, salinity, nutrients,
arid sediment. Compare the application and results of each
methodology/model and evaluate the potential to combine
existing models and technology into :one working system to
produce predictions of changing salinity, nutrients, and
sediment regimes resulting from specific proposed or planned
upstream activities.
Lead: Gulf State resource agencies and Mote Marine Laboratory.
Initiation Date: 1996
21, 22
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Chapter 4
Objective:
Conduct research on population and economic
projections in the Gulf of Mexico related to freshwater
needs and flows and related socio-political issues.
Action Item 31
Effects of Economic Growth on Freshwater Inflows to Gulf of
Mexico Coastal Systems
Determine how economic and population projections and
future demands for freshwater will affect freshwater inflows to
Gulf of Mexico coastal systems. Emphasis should be on
addressing areas with significant projected growth/loss and the
potential effects on the receiving waters of the Gulf of Mexico.
Lead; U.S. Department of Commerce.
Initiation Date: 1994
Action Item 32 - Use of Reclaimed Water to Replace Flow Losses to Gulf of
Mexico Coastal Systems
Conduct research on the use and optimal location of highly
treated reclaimed water (Clean Water Act advanced treatment
standards or better), including wetland treatment, to replace
flow losses to Gulf of Mexico coastal systems. Research should
utilize international examples.
Lead: U.S. Environmental Protection Agency, National
Aeronautics & Space Administration, and Gulf of Mexico
Program—Freshwater Inflow Committee.
Initiation Date: 1994
Action Item 33 - Gulf of Mexico Water Conservation Alternatives Research
Conduct research on potential Gulf of Mexico water
conservation alternatives on an ecological, economic, and
socio-political basis.
Lead: Gulf State resource agencies and U.S. Environmental
Protection Agency.
Initiation Date: 1995
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Chapter 4
Monitoring & Assessment
Establishing an adequate information base is very important for monitoring
freshwater inflow conditions and for measuring the success of this action agenda.
Current information should be used to develop a statistically valid baseline from
which to monitor changing conditions in the rates and distribution of freshwater
inflows to the Gulf of Mexico. Future activities and information collection can then
be incorporated into the data base. Gulfwide priorities need to be set and procedures
established to improve the inventorying and monitoring of this information
among agencies and programs.
Specific objectives and action items follow:
Objective:
Inventory all available data and identify data gaps
relating to water quality and quantity, water use factors,
and effects of freshwater inflow on Gulf of Mexico
estuarine productivity-including salinity patterns,
nutrient delivery and uptake, sediment regimes, land
use and land use changes, biological parameters,
geomorphology, and types of freshwater inflow (e.g.,
surface water, ground water, and other sources).
Action Item 34 - Gulfwide Priorities for Data Acquisition & Collection
Establish priorities for data acquisition and collection based on
Gulf of Mexico Program management objectives for
monitoring and other needs of the program.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with Data & Information Transfer Operations,
Southeast Regional Climate Center, and state and regional
water management agencies.
Initiation Date: 1994
38
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Chapter 4
NOTE: Action Items 35 and 36 are a generic set of actions for each group of
variables or parameters identified as Important under Action Item 34.
Action Item 35
Inventory of Available Data & Information Sources Relevant to
Gulf of Mexico Freshwater Inflows
Identify and inventory all federal, state, and private programs
relevant to Gulf of Mexico freshwater inflows. Emphasis
should be placed on early review of regional, comparable
sources such as the U.S. Environmental Protection Agency-
Environmental Monitoring & Assessment Program and
STORET.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with Data & Information Transfer Operations.
Initiation Date: 1994
Action lt«m 3«
Acquisition, Quality Assurance & Synthesis of Gulf of Mexico
Freshwater Inflow Data
Acquire, quality assure, and synthesize appropriate freshwater
inflow data for the Gulf of Mexico. Summarize data based on
quality and quantity available. Organize data using a
Geographic Information System (GIS) format.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with Data & Information Transfer Operations.
Initiation Date: 1995
25, 63
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Chapter 4
Aetlen Item 37 - Minimum Data Set for Gulf of Mexico Estuaries or Basins
Specify the minimum data set for each estuary or basin within
the Gulf of Mexico. The set specification should identify
variables, as well as geographic and temporal parameters.
Consideration should be given to data availability, critical
information needs for decision making, and cost factors.
Lead: Gulf of Mexico Program-Freshwater Inflow Committee,
in coordination with Data & Information Transfer Operations.
Initiation Date: 1995
-» 3
Action Item 38 * Feedback Loop for Gulf of Mexico Freshwater Data Collection
Based on results of data evaluation, evolving needs of other
action items, and any changes to Gulf of Mexico monitoring
objectives, reevaluate what freshwater related data need to be
collected (either primary or secondary collection).
Lead: Gulf of Mexico Program.
Initiation Date: 1996
-> 34
Objective:
Assess trends in freshwater inflows to the Gulf of
Mexico.
Aetlen Item 3»
Identification of Data Needed for Freshwater Inflow Trend
Assessment iin the Gulf of Mexico
Identify the temporal (including seasonally) and spatial
specificity needed to assess trends in freshwater inflow within
the Gulf of Mexico region.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with Data & Information Transfer Operations.
Initiation Date: 1995
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Chapter 4
Action Itom 4O • Inventory of Major Gulf of Mexico Watershed Modifications
Inventory past and identify projected future major watershed
modifications on a state by state basis in the Gulf of Mexico,
including land use, hydrologic modifications, dam projects,
and other structural alterations. This will serve as a baseline
planning tool, as well as provide valuable information for
public education.
Lead: Appropriate Gulf State agencies, in coordination with
Gulf of Mexico Program—Freshwater Inflow Committee.
Initiation Date: 1995
Action Itom 41 - Estimation of Naturalized Flows & Variability In the Gulf of
Mexico
Develop estimates of naturalized (pre-development) flows and
variability for comparison with present flows on an estuary by
estuary basis in the Gulf of Mexico.
Lead: Mote Marine Laboratory.
Initiation Date: 1995
Action Item 42 - Climatological Trends in the Gulf of Mexico
Integrate precipitation data for the Gulf of Mexico watershed
using accepted hydrological techniques to produce an historic
basnvscale precipitation record to use in analyses to determine
changes in runoff to each estuary relative to precipitation
within its watershed.
Lead: U.S. Geological Survey, in coordination with Texas
Water Commission, Florida's regional water management
districts, and Southeast Regional Climate Center.
Initiation Date: 1994
2 3
Action Itom 43 - Meteorological Trends in the Gulf of Mexico
Evaluate the contribution of tropical storms, hurricanes, and
thunderstorms to seasonal water budgets in the Gulf of Mexico.
Lead: National Oceanic & Atmospheric Administration--
National Weather Service.
Initiation Date: 1995
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Chapter 4
Objective:
Identify and evaluate causes of change in freshwater
inflow quantity and quality relative to location, volume,
and timing of change within an estuary or segment in
the Gulf of Mexico.
Action Item 44 - Identification & Ranking of Contributions to Causes of
Freshwater Inflow Change in the Gulf of Mexico
Identify and prioritize the causes of freshwater inflow change
within an estuary or estuary segment in the Gulf of Mexico.
Lead: Gulf State water resource agencies.
Initiation Date: 1996
5, 46
Action Item 45 - Future Agricultural/Industrial Management Practices Affecting
Runoff & Hydrogeologic Patterns in the Gulf of Mexico
Identify future agricultural and industrial management
practices and regulations likely to dramatically change basin
wide runoff patterns in the Gulf of Mexico.
Lead: U.S. Environmental Protection Agency, Soil
Conservation Service, and Gulf State agencies.
Initiation Date: 1996
Action Item 46 - Anthropogenic Activities Affecting Seasonal Runoff Patterns in
the Gulf of Mexico
Identify and prioritize the causes of freshwater inflow change
within an estuary or estuary segment in the Gulf of Mexico.
Lead: Gulf State water resource agencies.
Initiation Dale: 1996
5, 44
Action Item 47 - Groundwater Inputs to Freshwater in Gulf of Mexico Estuaries
Estimate ground water inputs, as a function of precipitation, to
each estuary in the Gulf of Mexico. .
Lead: U.S. Geological Survey, in coordination with Gulf State
water resource agencies.
Initiation Date: 1996
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Chapter 4
Action Item 48
Long-Term Climatic Effects on Surface Waters
Inflows to the Gulf of Mexico
Freshwater
Determine long-term climatic (sea level, rainfall) effects on
surface waters of the Gulf of Mexico and the impacts of changes
on freshwater inflows.
Lead: Southeast Regional Climate Center, in coordination with
state water management agencies.
Initiation Date: 1996
Objective:
Determine Gulf of Mexico estuarine resource-based
salinity requirements based on existing knowledge and
working hypotheses (inventory what has been done and
identify what needs to be done for major representative
ecosystems).
Action Item 49 - Salinity Requirements for Seagrasses in the Gulf of Mexico
Determine salinity requirements and physical parameters for
Gulf of Mexico seagrasses based on existing knowledge and
working hypotheses and determine future research needs.
Lead: National Marine Fisheries Service, in coordination with
Gulf State resource agencies and Gulf of Mexico Program--
Habitat Degradation Committee.
Initiation Date: 1995
24
Action Item SO
Salinity Requirements for Fish & Invertebrates in the Gulf of
Mexico
Determine salinity requirements and physical parameters for
fish and invertebrates of economic and ecological importance
in the Gulf of Mexico based on existing knowledge and
working hypotheses. Determine future research needs.
Lead: National Marine Fisheries Service, in coordination with
U.S.-Fish & Wildlife Service, Gulf State resource agencies, Sea
Grant Universities, and Gulf of Mexico Program-Living
Aquatic Resources Committee.
Initiation Date: 1995
24
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Chapter 4
Action Item 81 - Natural Rate o1f Change in Gulfwide Salinity Based on Tidal Scale
Determine the natural rate of change in Gulfwide salinity (or
any other factor) on a tidal (daily) scale based on existing
knowledge and working hypotheses. Determine future
research needs.
Lead: National Oceanic & Atmospheric Administration--
Strategic Assessments Branch, in coordination with state and
regional water management agencies.
Initiation Date: 1995
24
Action Item 52 - Gulf of Mexico Estuarine Flushing Times
Determine Gulf of Mexico estuarine flushing times based on
existing knowledge and working hypotheses and determine
future research needs.
Lead: National Oceanic & Atmospheric Administration--
Strategic Assessments Branch, in coordination with state and
regional water management agencies.
Initiation Date: 1995
-» 24
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Chapter 4
Objective:
Identify linkages and assess relationships among
freshwater inflows, salinity patterns, nutrient delivery
and uptake, sediment regimes, estuarine productivity,
other water quality parameters, and the adjacent Gulf of
Mexico.
Action Item S3 - Criteria & Process for Prioritizing Gulf of Mexico Freshwater
Inflow Linkages & Relationships for Evaluation
Develop criteria and a process to prioritize a limited list of Gulf
of Mexico freshwater inflow linkages and relationships for
evaluation, including the appropriate temporal scale.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1995
1, 3, 54, SS
Action Item 54 - Methodology to Identify Freshwater Inflow Relationships &
Linkages Within a Typical Estuary for Each Gulf State
Develop a methodology to completely identify freshwater
inflow relationships and linkages in a single or typical Gulf of
Mexico estuary or basin. Each state should develop this model
for the estuary or basin that best typifies state conditions.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1996
3, 6, 53, 55
Action Item 55 - Expansion of State Freshwater Inflow Methodologies to Other
Basins/Estuaries Throughout the Gulf of Mexico
Modify or expand the state model to explain relationships or
linkages in other basins or estuaries throughout the Gulf of
Mexico. The order in which other watersheds are addressed
depend on management priorities.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1997
4, 5, S3, 54
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Chapter 4
Aetlon Item 58
Gulfwide Characterization Workshops for Freshwater Inflow
Concerns
Convene a series of freshwater inflow characterization
workshops/beginning with workshops in each state and
culminating with a Gulfwide workshop. Experts on each
estuary or basin and subject matter experts will characterize
problems. The result will be a matrix that arrays problems
against basins.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with appropriate Gulf State agencies.
Initiation Date: 1994
1, 3, 4, 44, 54, 65
Objective:
Develop a Gulfwide monitoring program to assess the
effectiveness; of freshwater management actions on an
estuary specific (or estuary class) basis.
Action Item 87 • Management Objectives for Freshwater Monitoring Program
Design for Gulf of Mexico Estuaries
Identify or specify Gulf of Mexico management objectives to
provide the basis for a freshwater-related monitoring program
design for each Gulf estuary. Objectives stated should support
establishment of monitoring criteria such as data completeness,
extremes and rates of change, seasonality, and temporal scale.
Note - This Action Item should be part of the broad activities of
the Gulf of Mexico Program.
Lead; Gulf of Mexico Program.
Initiation Date: 1996
58, 59
Action Item 68 -Assessment of NAS Monitoring Approach for Gulf of Mexico Use
Determine the feasibility of using the National Academy of
Science approach (Managing Troubled Waters) to monitoring
program design and evaluation. Each state and the Gulf of
Mexico Program should conduct individual evaluations and
consider the feasibility of a Gulfwide approach.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee
and Data & Information Transfer Operations, in coordination
with appropriate Gulf State agencies.
Initiation Date: 1995
57, 59
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Chapter 4
Action Item 5*
Development of Gulf of Mexico Monitoring Standards &
Modification of Monitoring Plan Based on Planned Hydrologie
Changes
Develop Gulf of Mexico monitoring program, standards for use
with continuous monitoring and recording equipment for
appropriate parameters, e.g., freshwater flows, tidal flows,
salinity patterns, and ambient water quality parameters.
Prepare changes to the monitoring plan when the states
identify planned major hydrologic changes such as dam
construction and channel changes. Modifications should be
designed to capture freshwater flows before the hydrologic
change and impacts after the change.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee
and Data & Information Transfer Operations, in coordination
with appropriate Gulf State agencies.
Initiation Date: 1996
57, 58
Action Itom 60
Gulf of Mexico Protocols for Biological Parameters & Basin
Relationships
Develop Gulf of Mexico sampling protocols for biological
parameters (e.g., biomass, specific species) and basin system
relationships for which direct biological monitoring can be
used in place of physio-chemical monitoring.
Lead: Gulf State resource agencies and U.S. Environmental
Protection Agency.
Initiation Date: 1996
Action Item 61 - Freshwater Monitoring Cost/Benefit Study for the Gulf of Mexico
Conduct a study of monitoring costs and benefits for the Gulf of
Mexico to identify appropriate public and private parties for
covering the costs of monitoring programs related to
freshwater.
Lead: Gulf State resource agencies and Gulf of Mexico
Program—Data & Information Transfer Operations-
initiation Date: 1997
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Chapter 4
Action Item 62 - Gulf of Mexico Monitoring Coordination & Facilitation
Coordinate and facilitate communication, data management,
and related monitoring activities among all Gulf area public
and private institutions that are routinely conducting
monitoring programs.
Lead: Gulf of Mexico Program—Data & Information Transfer
Operations.
Initiation Date: 1995
Action Item 63 - Gulfwide GIS & Data Management System
Develop a Gulf wide, basin-based "super" Geographic
Information and Data Management System to support
monitoring and assessment. The system would include all
freshwater flow quantity data, related variables, structures, and
meteorological data. Note: Need to develop a cross issue
Gulfwide monitoring strategy, including appropriate modeling
activities. , •. - . .
Lead: Gulf of Mexico Program—Data & Information Transfer
Operations.
Initiation Date: 1997
1, 25, 36, 57, 60
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Tho Unfinished Agenda
Chapter 4
Public Education & Outreach
People living in two-thirds of the U.S. ultimately affect the environmental quality
of the Gulf of Mexico. Alternatively, the entire population of the U.S. can
potentially be affected by the environmental quality of the Gulf. Therefore, effective
environmental policy requires an ongoing commitment from an informed
citizenry. Public outreach nurtures such a commitment. Public information,
education, and involvement are three components of an effective outreach strategy,
which can reap significant benefits both for the Gulf of Mexico and for citizens
utilizing its resources. More and more, public outreach is recognized as an effective
resource management tool to address problems resulting from individual actions
and to create a sense of stewardship within the community.
Public outreach can foster recognition of the Gulf as a regional and national
resource; stimulate civic, governmental, and private sector support for changing
lifestyles; and develop the financial commitments necessary to preserve the
resource.
The overall public education strategy for freshwater inflows is to use existing
resources as much as possible to get the message out to target audiences, which will
include the use of bilingual materials. New workshops and curricula should be
sponsored only when existing ones are not sufficient. Corporate sponsorships
should be considered for all education and involvement materials, activities, and
events wherever possible. Key topics for freshwater inflow include:
• Relationships/interactions among freshwater and estuarine systems;
• Freshwater inflow and its impacts on water quality;
• Basic discussion of pollution, its sources, and impacts; and
• A watershed approach to freshwater inflow problems.
Specific objectives and action items follow:
Gulf of Mexico Freshwater Inflow Aeilon Agenda (3.1)
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The Unfinished Agenda
Chapter 4
Objective:
Promote the basin-wide public awareness of ecological,
economic, aind health impacts associated with
alterations of freshwater Inflows to estuarlne systems
and the cumulative role of those estuaries for
sustaining the health of the Gulf of Mexico.
Action Item 64 - Process to Identify Education & Outreach Needs for Gulf of
Mexico Freshwater Inflows
Institute a standard process for the Gulf of Mexico Program
Office to identify the public education and outreach needs for
freshwater inflow and other issue areas. The process should
help the Office obtain a comprehensive list of those needs by
constituency. These needs would be summarized and specific
actions developed to address the most significant needs. Note
This Action Item should be part of the broad activities of the
Gulf of Mexico Program.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and other Issue Committees.
Initiation Date: 1994
Action Item 66 - Technical Overview Document to Describe Gulf of Mexico
Freshwater Inflow Issues
Develop a scientifically rigorous overview and synthesis
document, characterizing the problems associated with Gulf of
Mexico estuaries' freshwater inflow. This document would
describe the freshwater flow and salinity patterns in Gulf of
Mexico estuaries as this information becomes available. It
would also include the historic and projected future changes in
the estuaries' freshwater inflow. The document would become
the primary source of technical information for articles and
publications.. .. ;
Lead; Gulf of Mexico Program—Freshwater Inflow Committee.
Initiation Date: 1996
-» 4O, 44, 56
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The Unfinished Agenda
Chapter 4
Action Item 66 - Existing Publications That Reach the Gulf of Mexico Public on
Freshwater Inflow Issues
Survey existing newsletters and other publications to identify
those that can inform the general public about problems
associated with freshwater inflow in the Gulf of Mexico. After
identifying these newsletters, prepare articles that address
specific topics, audiences, and geographic areas. Use existing
mechanisms to write, incorporate, and distribute these articles
to the newsletters.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1995
79
Action Item 67 - Freshwater Inflow Curriculum
Identify lesson plans, outlines, etc. that describe problems
associated with freshwater inflow. If necessary develop such
materials. Modify a prototype watershed approach for water
resources, such as Mote Marine Laboratory's "Drop of Water,"
to incorporate a freshwater inflow curriculum unit. Then,
incorporate the modified prototype into existing
environmental curricula. Conduct specific initiatives to
increase teacher awareness of environmental issues, including
announcements of the freshwater inflow unit in existing
newsletters designed to reach teachers and science coordinators.
Use the Elder Hostel Program to provide volunteers to teach
this unit where feasible.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and Mote Marine Laboratory.
Initiation Date: 1996
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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The Unfinished Agenda
Chapter 4
Action Item 68
Freshwater InlFlow Workshops for Educators in the Gulf of Mexico
Region
Modify existing or institute new annual workshops to increase
teacher awareness of freshwater inflow issues in the Gulf of
Mexico. The workshops should include a summary of the
latest data, research, and information and should help identify
the need for related educational materials on freshwater inflow
and other environmental issues. The state and national
forums should be supported by state governments as well as
school administrators.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and state departments of education.
Initiation Date:: 1997
Action Item 69 - Gulf of Mexico Freshwater Inflow Media Kits
Develop media kits that include public service announcements
(PSAs), news releases, photographs, and, brochures describing
problems associated with freshwater inflow in the Gulf of
Mexico. Media kits should be professionally done, timely, and
always up-to-date, and should include a,local technical contact.
Specific topics might include use and reuse (e.g., water
conservation). Existing organizations/associations, such as the
American Waterworks Association, should be surveyed for
material that might be included.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in. coordination with Freshwater Inflow
Committee.
Initiation Date; 1997
Action Item TO - Gulf of Mexico Freshwater Inflow Public Broadcasting Program
Develop a thirty-minute freshwater inflow program to
broadcast on public radio and television. The program should
inform the general public about problems associated with
freshwater inflow in the Gulf of Mexico, including specific
technical issues about the quantity and quality of freshwater
inflow.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1997
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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The Unfinished Agenda
Chapter 4
Action Itom 71 - Gulf of Mexico Freshwater Inflow Information Portfolio
Develop a portfolio of basic information about freshwater
inflow in the Gulf of Mexico that addresses the following
issues: 1) implications for bay, estuary, and human health; 2)
selected technical issues; and 3) other related problems. Make
the portfolio available to individuals who request information
for news stories, newsletters, and environmental curricula.
Lead: Gulf of Mexico Program-Freshwater Inflow Committee,
in coordination with Public Education & Outreach Operations.
Initiation Date: 1997
65, 67
Action Itom 72 - Gulf of Mexico Freshwater Inflow Clearinghouse
Sponsor a clearinghouse/repository for freshwater inflow-
related public education activities, events, and materials.
Coastal managers and educators across the Gulf could access the
clearinghouse/repository through an "800" number or the Gulf
program's existing bulletin board system.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1995
Action Itom 73 - Articles on Freshwater Inflow Issues in the Gulf of Mexico
Interact with local media organizations, especially newspapers,
to encourage the publication of feature articles on freshwater
inflow issues in the Gulf of Mexico. These articles should
address the unique freshwater inflow problems associated with
the readership's geographic area.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1995
6 9
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The Unfinished Agenda
Chapter 4
Aeilen Item 74 - Gulf wide Water Resources & Fisheries Management Integration
Integrate the local and regional management of water resources
and fisheries through state water resources boards in the Gulf
of Mexico. This should help coordinate policies and research
associated with water resources and fisheries management.
Lead; Appropriate Gulf State agencies.
Initiation Date: 1996
Action Item 75
Establishment of Land Owners Associations in the Gulf of
Mexico Region
Foster the formation of associations of waterfront/shoreline
property owners who can educate themselves about the effects
of specific behavior on the quality of freshwater entering bays
and estuaries in the Gulf of Mexico. In addition, form specific
action programs for property owners addressing freshwater
inflow and other Gulf of Mexico Program action areas (e.g.,
toxic substances & pesticides, nutrient enrichment, marine
debris, and habitat degradation).
Lead: Gulf of Mexico Program Citizens Advisory Committee,
in coordination with appropriate Gulf of Mexico Program Issue
Committees.
Initiation Date: 1997
Action Item 76 - Awards Program for Gulf of Mexico Freshwater Inflow Issues
Institute an award program for citizens and non-prof it/other
organizations who successfully address freshwater inflow
problems in the Gulf of Mexico. The award should provide
additional incentives to sponsor freshwater inflow projects.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1996
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Chapter 4
Action lt«m 77 - Gulf of Mexico Urban Outreach Programs
Develop and/or sponsor public education materials and events
on freshwater inflow targeted specifically to youth in urban
areas and other groups that may be culturally and/or
geographically distanced.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and other Issue Committees.
Initiation Date: 1996
Action Item 78 - Gulf of Mexico Model Landscape Program
Develop and institute a model program designed to encourage
environmentally-sound landscape practices in neighborhoods,
public sites, business centers, and school yards.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with appropriate Gulf of Mexico
Program Issue Committees.
Initiation Date: 1997
Gulf of Mexleo Freshwater Inflow Action Agenda (3.1)
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The Unfinished Agenda
Chapter 4
Objective:
Promote the basin-wide awareness of federal, state, and
local government officials and decision-makers of the
ecological, economic, and health impacts associated
with alterations of freshwater inflows to estuarine
systems and the cumulative role of those estuaries for
sustaining the health of the Gulf of Mexico.
Action Item 79
Existing Publications That Reach Gulf of Mexico Officials on
Freshwater Inflow Issues
Conduct a survey to identify existing newsletters that can
inform Gulf of Mexico region elected officials about the
problems associated with freshwater inflow. Once these
newsletters are identified, write articles designed to address
specific topics, audiences, and geographic areas. Place these
articles in the selected newsletters through existing
mechanisms.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1995
6 6
Action Item BO • Technical Papers on Gulf of Mexico Freshwater Inflow
Prepare and present "short" technical papers to key senior
federal decision-makers. These papers will set a general context
for understanding issues associated with freshwater inflow in
the Gulf of Mexico, as well as address specific technical issues.
Lead: Gulf of Mexico Program—Freshwater Inflow Committee,
in coordination with Public Education & Outreach Operations.
Initiation Date: 1996
65, 81
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Tho Unfinished Agenda
Chapter 4
Action Itom 81 - Gulfwide Seminars on Freshwater Inflow Issues
Identify local and regional seminars where the Gulf of Mexico
Program can disseminate information regarding freshwater
inflow issues to elected officials and their staff people. If
necessary, sponsor such seminars. These seminars should be
held in something less than a public setting. They will help
elected officials understand the general policy and specific
technical issues associated with freshwater inflow.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and other Issues Committees.
Initiation Date: 1997
8 O
Action Itom 82 - Culfwide Road Shows on Freshwater Inflow Issues
Sponsor educational road shows for appropriate teams of
coastal managers to brief elected officials in the Gulf of Mexico
region and their staff on issues pertaining to freshwater inflow.
Each road show should result in a series of specific actions for
the elected official.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and other Issues Committees.
Initiation Date: 1997
Action Item 83 - Videos on Freshwater Inflow Issues in the Gulf of Mexico
Identify and/or develop short (ten minute) videos that detail
the issues associated with freshwater inflow in the Gulf of
Mexico region, as well as profile the related technical issues.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1997
70, 82
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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The Unfinished Agenda
Chapter 4
Action Item 84
Information io Gulf of Mexico Legal Professions About
Freshwater Inflow Issues
Identify bar associations, judges, and law enforcement officials
throughout the Gulf of Mexico who should be informed about
the legal issues associated with freshwater inflow. Develop and
distribute specialized outreach materials for this audience.
Lead: Gulf of Mexico Program-Public Education & Outreach
Operations, in coordination with Freshwater, Inflow
Committee arid other Issues Committees.
Initiation Date: 1997
Objective:
Promote basin-wide public involvement to address the
ecological, economic, and health impacts associated
with alterations of freshwater inflows to estuarine
systems and the cumulative role of those estuaries for
sustaining the health of the Gulf of Mexico.
Aotlon lt«m 85
Endorsement of Gulfwide Public Involvement Activities Related
to Freshwater Inflow Issues
Endorse or sponsor specific Gulfwide public involvement
activities and events designed to address problems associated
with freshwater inflow. Many of the National Estuary
Programs already sponsor these types of public events. This
could include storm water stenciling packets and activities,
volunteer monitoring/sampling (one time and regular
sampling), festivals such as Galveston Bay Days, programs such
as Florida Neighborhoods, and Galveston Bay's Pollution
Reporting Hotline. Consider the use of corporate sponsorships
to cover printing and other expenses. For example, Clorox is
sponsoring a one day volunteer monitoring of the Mississippi
River.
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee and other Issues Committees.
Initiation Date: 1995
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Tho Unfinished Agenda
Chapter 4
Action Item 86
Development of "What I Can Do" Lists to Address Freshwater
Inflow Issues
Develop action-oriented citizen "to do" lists, which outline
activities and behaviors that address freshwater inflow issues
in the Gulf of Mexico. Where possible, influence existing state
and local lists, such as Tampa and Sarasota Bays' "Bay Repair
Kit" and Galveston Bay's "Resident Handbook."
Lead: Gulf of Mexico Program—Public Education & Outreach
Operations, in coordination with Freshwater Inflow
Committee.
Initiation Date: 1995
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
98
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in Closing
In Closing...
We intend this document to be a beginning, not an end.
Our hope is that this Action Agenda will serve as an
inspiration and a call to action for the millions who live
and work in the Gulf of Mexico region. Together, our
coordinated actions can make a difference and eliminate
freshwater inflow concerns in the Gulf of Mexico system.
The Gulf of Mexico Program
Freshwater Inflow Committee
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
99
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Federal & State Framework
Appendix A
FEDERAL LEVEL
International Boundary and Water Commission (IBWC).
The International Boundary and Water Commission was established by treaty on
March 1,1889, between the U.S. and Mexico. The Water Treaty of February 3,1944,
expanded the jurisdiction, responsibilities, and powers of the Commission and
changed the name to the International Boundary and Water Commission, U.S. and
Mexico. Prior to 1889, temporary commissions had performed the first joint projects
between the two countries in surveying and demarcating the international
boundary in accordance with the treaties of 1848 and 1853.
The Commission is an international body consisting of a U.S. and a Mexican
Section, each funded by its government, and headed by an Engineer-Commissioner
appointed by the respective President. The U.S. Commissioner reports to the
Department of State for policy guidance, and the Mexican Commissioner reports to
Mexico's Secretariat of Foreign Relations. The two sections maintain their
respective headquarters in the adjoining cities of El Paso, TX, and Ciudad Juarez,
Chihuahua, at the mid-point along the boundary. In addition, each section
maintains appropriate field offices as necessary to operate, maintain, and monitor
joint projects, and effect close coordination.
The mission of IBWC is to apply the provisions of the numerous boundary and
water treaties and related agreements between the two countries and basically
includes the following six major responsibilities: 1) demarcation of the land
boundary; 2) maintenance of the river boundary; 3) control of floods from the
international rivers; 4) distribution of the waters of the Rio Grande and Colorado
Rivers; 5) operation and maintenance of the international dams, reservoirs, and
hydroelectric plants on the Rio Grande; and 6) solution of border water quality
problems, including adverse salinity, sanitation, and groundwater impacts. The
Commission, through negotiation and approved cooperative projects, facilitates the
solution of international boundary and water problems to improve the quality of
life for the people on both sides of the border and contributes to better relations
between the two countries.
Tennessee Valley Authority (TVA)
Since 1933, the Tennessee Valley Authority (TVA) has been charged with
developing and managing the natural resources of the Tennessee Valley. TVA built
the dams that created the Valley's reservoirs; with that came the responsibility to
operate and maintain the waterways for the maximum benefit of all Valley
residents. As stewards of Valley water resources, a major part of TVA's mission is
to ensure that enough water of sufficiently high quality is available to meet the
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Fadoral & State Framework
Appendix A
needs of the population. The 1933 TVA Act specifically defines TVA's priorities for
managing the Valley's waterways. In order of priority, TVA is obligated to:
1) protect against flooding; 2) maintain an 11 foot navigation channel in the
mainstream of the Tennessee River; 3) produce inexpensive electricity using
hydropower; and 4) operate the reservoirs in a manner that preserves the
environment and protects water quality. Maintaining pool levels suitable for
recreation and aesthetics, fluctuating the water levels to reduce mosquito
population, providing flows to help assimilate municipal wastewaters, providing
enough water for industrial users, and adjusting levels to enhance wildlife and
waterfowl habitat are a few of the many ways TVA reservoirs are managed for
multiple uses. TVA sets limits on how fast water can be released from the
reservoirs so that fish and wildlife populations will not be affected.
U.S. Environmental Protection Agency (USEPA)
USEPA has responsibility for several environmental protection laws that have the
potential to influence freshwater inflows to the Gulf of Mexico. These statutes and
related programs are discussed below.
Federal Water Pollution Control Act of 1972 (FWPCA). The U.S. Congress in
1972 significantly amended the Federal Water Pollution Control Act of 1948
and produced further amendments in 1977, 1981, and 1987. These
amendments are also commonly known as the Clean Water Act (CWA). The
objective of the Act is to restore and maintain the quality of our water
resources to protect the health of humans, fish, shellfish, and wildlife from
harmful pollutants. CWA establishes national water quality goals and creates
a national permit system with minimum standards for the quality of the
discharged waters (effluent). CWA does not set specific standards for water
bodies, but does provide guidance to the states. States, however, are required
to establish standards based on the designated uses of these waters.
Waters of the U.S. protected by the CWA include rivers, streams, estuaries,
the territorial seas, and most ponds, lakes, and wetlands. In determining
waters that are within the scope of the CWA, Congress intended to assert
federal jurisdiction to the broadest extent permissible under the commerce
clause of the Constitution. One factor that establishes a commerce connection
is the use or potential use of waters for navigation. Other factors include (but
are not limited to) use of a wetland (or other water) as habitat by migratory
birds, including waterfowl; use by a federally listed endangered species; or use
for recreation by interstate visitors.
CWA Section 404 regulates the discharge of dredged and fill material into
waters of the U.S to ensure that such discharges comply with environmental
requirements. Activities regulated by Section 404 include discharges of
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dredged and fill material commonly associated with activities such as port
development, channel construction and maintenance, fills to create
development sites, transportation improvements, and water resource projects
(such as dams, jetties, and levees). Other kinds of activities, such as land
clearing, are regulated as Section 404 discharges if they involve discharges of
dredged or fill material (e.g., soil) into waters of the U.S. CWA also includes
specific exemptions from permitting requirements for certain activities under
Section 404(f)(l), such as maintenance of currently serviceable structures (e.g.,
dikes, dams, levees, ditches); normal farming, silviculture, and ranching
practices; and construction or maintenance of farm or forest roads.
USEPA has primary roles in several aspects of the CWA Section 404 program
including development of the environmental guidelines by which permit
applications must be evaluated, review of proposed permits, prohibition of
discharges with unacceptable adverse impacts, approval and oversight of state
assumption of the program, establishment of the jurisdictional scope of
waters of the U.S., and interpretation of Section 404 exemptions. As a jointly
administered program, USAGE and USEPA share responsibility for enforcing
the Section 404 Program. USEPA can also enforce against non-compliance
with permit conditions; however, USEPA generally focuses its resources
towards discovering and enforcing against unpermitted (unauthorized)
discharges.
National Estuary Program (NEP). In 1987, the National Estuary Program was
established by an amendment to the Clean Water Act. The purpose of the
Program is to identify nationally significant estuaries, to protect and improve
their water quality, and to enhance their living resources. Under the
Program, which is administered by USEPA, comprehensive management
plans are developed to protect and enhance environmental resources. The
governor of a state may nominate an estuary for the Program and request that
a Comprehensive Conservation and Management Plan (CCMP) be developed
for that estuary. Representatives from federal, state, and interstate agencies,
academic and scientific institutions, industry, and citizen groups work during
a five year period to define objectives for protecting the estuary, to select the
chief problems to be addressed in the Plan, and to ratify a pollution control
and resource management strategy to meet each objective. At present, there
are twenty-one estuaries in the Program; five of these estuaries are in the Gulf
of Mexico (Galveston Bay, Tampa Bay, Sarasota Bay, Corpus Christi Bay, and
the Barataria-Terrebonne Estuarine Complex).
Safe Drinking Water Act of 1974, as amended. Under the Safe Drinking
Water Act, grants are available to states from USEPA to develop wellhead
area protection plans for public groundwater drinking supply recharge areas.
The grants can cover from 50 to 90 percent of the costs of establishing and
running a protection program. If a wetland is hydrologically located such that
any contaminants entering it are reasonably likely to reach a public water
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supply, the protection program may apply to activities in the wetland.
Decreasing freshwater inflow to and consequent increasing salinities of Gulf
of Mexico estuaries could have potential impact on wellhead protection in
low-lying areas.
National Environmental Policy Act of 197O (NEPA). NEPA requires that all
federal agencies recognize and give appropriate consideration to
environmental amenities and values in the course of their decision-making.
In an effort to create and maintain conditions under which humans and
nature can exist in productive harmony, NEPA requires that federal agencies
prepare an environmental impact statement (EIS) prior to undertaking major
federal actions that significantly affect the quality of the human environment.
Within these statements, alternatives to the proposed action that may better
safeguard environmental values are to be carefully assessed.
U.S. Department of Defense
Army Corps of Engineers (USACE)
USAGE has responsibility in its water resources projects for flood control,
hydropower production, navigation, water supply storage, recreation, and fish and
wildlife resources.
• Rivers and Harbor Act of 1899. The Rivers and Harbors Act regulates all
construction in or modification of traditionally navigable waters. The Act
provides that the construction of dams and dikes, the dumping of refuse
materials, or "any obstruction or alteration" in navigable waters or their
tributaries, not affirmatively authorized by Congress, are expressly prohibited
unless an authorized official of the USAGE has issued a permit for such
activity. The Act gives USAGE discretion to deny a permit for the above
activities in the interests of navigability or anchorage. USAGE has
promulgated regulations from time to time to reflect its evolving policies
regarding these interests. However, in recent years, Congress has enacted
legislation dealing with water-related interests other than navigation, and has
required USAGE to coordinate with or defer to the judgment of other state
and federal agencies vis-a-vis the issuance of permits. These statutes include
the Fish and Wildlife Coordination Act (see USFWS), the Federal Water
Pollution Control Act, and the Marine Protection, Research, and Sanctuaries
Act. USEPA> USFWS, and NMFS are the federal agencies most frequently
involved in the coordinating effort.
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National Flood Control Act of 1928 (as amended). The National Flood
Control Act regulates streamflow of the Mississippi and Atchafalaya Rivers.
Since 1977, the USAGE has regulated the streamflow in the lower reaches of
these rivers so that 70 percent of the total flow for both rivers is in the
Mississippi River and 30 percent is in the Atchafalaya River.
Water Resources Development Act of 1986. This act provides for
modification in the structure and operation of existing water resources
projects for the purpose of improving the quality of the environment in the
public interest. USAGE districts perform coastal habitat restoration projects
under the authority of Section 1135 of this act, in cooperation with other
federal agencies under the Coastal America Program, National Estuary
Program, and Cooperative Agreement with NMFS for Coastal Habitat
Restoration.
Coastal Wetlands Planning, Protection & Restoration Act (CWPPRA).
CWPPRA establishes a mechanism to plan and fund implementation of
wetland protection and restoration projects in coastal Louisiana. Freshwater
inflow and sediment enrichment are important aspects of these plans.
Planning and implementation activities are managed by a six-person/federal-
state task force. In addition, CWPPRA calls for development of a
Conservation Plan for the State of Louisiana, and provides funds for
matching grants to assist other coastal states in implementing wetland
conservation projects (i.e., projects to acquire, restore, manage, and enhance
real property interest in coastal lands and waters). Five years of recurring
funding is established up to $50 million/year, 70 percent for Louisiana with 75
percent-25 percent federal/state cost sharing. Extension of authority and
funding is possible, but is contingent on progress.
Clean Water Act Section 4O4 (see also: USEPA). USAGE is authorized, after
notice and opportunity for a public hearing, to issue permits for the discharge
of dredged or fill material. USAGE also has primary responsibility for
monitoring and enforcement of compliance with Section 404 permit
conditions. States can assume a portion of the permitting program from the
federal government (for some waters only), but there has been limited
interest by the states. USEPA works with USAGE during the permit decision
process, whenever possible, to ensure unacceptable adverse impacts are
avoided, and most concerns are resolved through this interagency
consultation. USAGE and USEPA have developed a process through a
Memorandum of Agreement (MOA) to quickly resolve any differences over
permit decisions. FWS and NMFS have similar agreements with USAGE.
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U.S. Department of Agriculture (USDA)
Soil Conservation Service (SCS)
SCS is the U.S. Department of Agriculture's primary technical agency in the areas of
soil and water conservation and water quality. SCS focuses its assistance on non-
federal land. It works primarily with private landowners in planning and applying
measures to reduce soil erosion, conserve water, protect and improve water quality,
and protect other renewable natural resources such as plants, animals, and air. The
guiding principle is the use and conservation treatment of the land and water in
harmony with its capabilities and needs.
SCS has an office in almost every county in the U.S., where it works closely with
local subdivisions of state government called Soil and Water Conservation Districts.
The conservation districts are governed by local people and typically have legislative
mandates to plan and implement comprehensive soil and water programs within
their boundaries. These boundaries usually coincide with county lines.
SCS's basic authorities were created by P.L. (74) - 46, P.L. (83) - 566, and P.L. (78) - 534.
Program authorities were added under various Farm Bills including those enacted
in 1961 (Resource Conservation & Development), 1988 (Swampbuster, Sodbuster,
Conservation Compliance, and Conservation Reserve Program) and 1990 (Wetlands
Reserve Program and others). Under the Swampbuster provisions, SCS assists
landowners to identify and protect wetlands. Loss of U.S. Department of
Agriculture benefits and severe economic consequences can result for agricultural
producers who convert wetlands to make possible the production of agricultural
commodities.
SCS also conducts soil surveys and operates a system of twenty-seven Plant
Materials Centers for selecting, developing, testing, and releasing plants for use in
conservation programs. SCS also works with private landowners and others to
preserve, protect, and restore wetlands and to develop wildlife and fisheries habitat.
U.S. Department off Commerce (USDOC)
National Oceanic & Atmospheric Administration (NOAA)
NOAA is a lead federal agency in the development and dissemination of scientific
information and products for the nation's estuarine and coastal ocean waters.
NOAA provides a wide range of observational, assessment, research, and predictive
services for estuarine and coastal ocean regions. In the Gulf of Mexico, NOAA
maintains coastal and marine research facilities, National Estuarine Research
Reserves, and National Marine Sanctuaries, oversees approved Coastal Zone
Management Plans in three coastal states, and has direct ties to universities and
colleges through the National Sea Grant College Program. NOAA has developed an
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array of programs to address not only national-scale estuarine issues, but also
specific problems affecting individual estuarine and coastal ocean systems.
• National Estuarine Inventory (NEI). NEI is a series of activities, within the
Office of Ocean Resources Conservation and Assessment (ORCA), that define
and characterize the nation's estuarine resource base and develop a national
estuarine assessment capability. NO A A began NEI in 1983 because no
comprehensive inventory of the nation's estuaries or their resources existed,
despite increased conflicting demands for the goods and services they
provide: habitat for fish and wildlife; food; areas for recreation; water
disposal; energy; and transportation. Four major NEI atlases, six national data
bases, and numerous technical reports containing thematic information
about the nation's estuaries have been produced. NOAA continues to
evaluate the scale and scope of information in NEI and make the necessary
additions and refinements to improve its capability to assess the nation's
estuaries.
• Coastal Zone Reauthorfzation Act of 1S9O. The purpose of this act is to
effectively manage the nation's rich coastal zone, recognizing it as a resource
of many values: i.e., natural, commercial, recreational, industrial, and
aesthetic. Management power and authority is placed at the state level, with
the federal government establishing standards and playing a coordinating
role. All federal activities, including permitting, licensing, and financial
assistance, must be consistent with approved state coastal zone management
plans. The Act specifically recognizes that fish shellfish, and other living
marine resources are ecologically fragile and therefore vulnerable to the
activities of humans.
National Marine Fisheries Service (NMFS)
The specific mission of NMFS is stewardship of the nation's living marine
resources, including fishery species and protected species (e.g., marine mammals
and sea turtles). The primary activities of NMFS are the routine assessment of the
status of stocks and the management of stocks through regulation of fisheries.
Preservation of habitat is recognized by NMFS as essential to the long-term
sustainability of marine resources and protected species. Although NMFS has no
direct regulatory control over habitat, NMFS has a Habitat Conservation Program
and actively works to conserve the habitat necessary to living marine resources and
protected species by reviewing and commenting on licensing, permitting,
legislative, and administrative activities potentially affecting such habitat. The
authority for this involvement by NMFS in habitat conservation is provided by the
Magnuson Fishery Management Act, U.S. Fish and Wildlife Coordination Act (see
USFWS), NEPA (see USEPA), and CWA (see USEPA). The Habitat Conservation
Program in NMFS is supported by habitat research, which develops information on
the ecological relationship between living marine resources and their habitat.
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The Southeast Regional Office (SERO), headquartered in St. Petersburg, Florida,
handles NMFS responsibilities in the Gulf of Mexico and has a Habitat
Conservation staff. In addition to performing stock assessments, the Southeast
Fisheries Science Center (SEFSC), with laboratories in several Gulf Coast States,
conducts research to support the NMFS Habitat Conservation Program in the
Southeast. Estuarine-related habitat research in the Gulf of Mexico currently is
conducted primarily at the Galveston, Texas, and Beaufort, North Carolina,
laboratories. A new SEFSC laboratory, to be devoted to habitat research, will soon be
opening in Lafayette, Louisiana. SERO has influenced several projects involving
freshwater inflow. The SEFSC has conducted some research concerning the effect of
freshwater inflow changes.
• Magnuson Fishery Conservation and Management Act of 1976 (as
amended). The major purposes of this Act are: 1) to take immediate action
to conserve and manage the fishery resources found off the coasts of the U.S.
and the anadromous species and Continental Shelf fishery resources of the
U.S.; 2) to establish Regional Fishery Management Councils; and 3) to prepare,
monitor, and revise fishery management plans (FMPs) which will achieve
and maintain, on a continuing basis, the optimum yield from each fishery.
Each FMP includes readily available information regarding the significance of
habitat to the fishery and an assessment of the effects of habitat changes on
the fishery. Each Council may comment on, or make recommendations
concerning, any activity undertaken, or proposed to be undertaken, by any
state or federal agency, including dams and river diversion, that, in the view
of the Council, may affect the habitat of a fishery resource under its
jurisdiction. By special agreement between NMFS and the Gulf of Mexico
Fishery Management Council, NMFS reports to regulatory agencies may also
represent or convey the views and recommendations of the Council.
National Weather Service (NWS)
NWS has three programs directed toward coastal and estuarine waters. The
Hurricane Guidance Program, the Tsunami Warning Program, and the Marine
Weather Warning Forecast Program provide timely forecasts and warnings for
coastal and estuarine waters. Other activities related to coastal and estuarine waters
are the marine forecasts and advisories routinely issued by NWS forecast offices. In
addition, the National Meteorological Center carries out operational storm surge
modeling to announce warnings during the passage of hurricanes. These models
have also been used to determine hurricane vulnerability in estuarine areas.
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National Environmental Satellite, Data, and Information Service
(NESDIS)
NESDIS conducts several coastal and estuarine related activities. The Assessment
and Information Services Center (AISC) conducts studies on satellite remote-
sensing application and use of numerical model data for circulation and bathymetry
application and for simulation of sediment transport. The National Environmental
Data Referral Service (NEDRES) is a computerized, online data base inventory that
facilitates environmental data identification for ocean and coastal regions.
National Flood Insurance Program (NFIP)
For property owners to be eligible for federally subsidized flood insurance, their
communities must adopt floodplain management regulations that will minimize
future flood damage. Adoption is typically accomplished by incorporating the
regulations into the local zoning ordinances and building codes. The Program's
restrictions on floodplain development may, in effect, protect wetlands adjacent to
the flood-prone waterway. Communities joining NFIP are rewarded with the
incentive of substantial flood insurance coverage, whereas communities that do not
participate are indirectly penalized by decreased funding for acquisition and
construction purposes.
U.S. Department of the Interior (USDOI)
USDOI has responsibility for most nationally-owned public lands and natural and
cultural resources. This includes fostering the wise use of land and water resources,
protecting fish and wildlife, preserving the environmental and cultural values of
national parks and historical places, and providing for the enjoyment of life
through outdoor recreation. USDOI assesses energy and mineral resources and
works to assure that their development is in the best interests of the citizens of the
U.S. USDOI also promotes the goals of the Take Pride in America campaign by
encouraging stewardship and citizen responsibility for public lands and promoting
citizen participation in their care.
Bureau of Reclamation
The mission of the Bureau of Reclamation is to assist states, local governments, and
other federal agencies in stabilizing and stimulating local and regional economies,
enhancing and protecting the environment, and improving the quality of life
through management, conservation, and development of water and related land
resources. The Bureau has 17 resource programs nationwide. Reclamation projects ;
provide for some or all of the following concurrent purposes: irrigation water
service, municipal and industrial water supply, hydroelectric power generation,
water quality improvement, groundwater management, fish and wildlife
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enhancement, outdoor recreation, flood control, navigation, river regulation and
control, and system project beneficiaries. The Bureau also arranges for repayment to
the government of reimbursable costs incurred in the construction and operation of
water resource projects.
U.S. Fish & Wildlife Service (USFWS)
USFWS works under several authorities to protect fish and wildlife species and to
protect, restore, and enhance their habitats. Amendments to the Federal Power Act
in 1935, and in 1986 (see FERC), added requirements to incorporate fish and wildlife
concerns in licensing, relicensing, and exemption procedures for hydropower
facilities. Sections of the Water Resources Development Act (see USAGE) provide
for modification in the structure and operation of existing water resources projects
for the purpose of improving the quality of the environment in the public interest.
• Fish and Wildlife Coordination Act of 1958 (as amended). The purpose of
the Act is to ensure that fish and wildlife concerns are considered equally
with navigation, landfill, hydroelectric power generation, flood control, and
other water resource interests whenever a federal agency plans, licenses, or
permits a watercourse modification for any purpose. The Act, as amended,
and as modified by Reorganization Plan No. 4 of 1970, which transferred
certain Department of Interior functions to the Department of Commerce,
mandates that the public agency performing or permitting any water
diversion, impoundment, dredging, filling, or other watercourse control or
alteration shall consult with the federal and state fish and wildlife agencies to
determine the impacts of the project on fish and wildlife. That agency may
incorporate suggestions for protecting, conserving, and enhancing wildlife
resources into the project plan.
Endangered Species Act of 1972 (as amended). The major purposes of this
Act are to provide a means whereby the ecosystems upon which endangered
and threatened species depend may be conserved and to provide a program
for the conservation of such endangered and threatened species. The Act also
provides for the designation of critical habitats for those species, as needed.
Such designated habitats should not be available for installation of dams,
reservoirs, and water diversion structures if the structures would eliminate,
degrade, or make less accessible any of the physical or biological features
found essential to the conservation of the species.
National Park Service (NPS)
NPS administers an extensive system of public lands, including lakeshores and
seashores, set aside for the protection of natural environments, the preservation of
historic properties, and the education and enjoyment of all citizens. NPS is
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responsible for four separate areas in southern Florida that total in excess of two
million acres—Biscayne, Everglades, and Dry Tortugas National Parks and Big
Cypress National Preserve. Both the South Florida Water Management District and
the USAGE have responsibility for the management of the water supply.
An important part of the Gulf of Mexico watershed is the Everglades National Park,
which is considered the most threatened national park in the National Park System.
The river component is now designated the third most threatened river in the U.S.
The park includes 607,050 hectares (1.5 million acres) of water and land, positioned
at the southern tip of the Florida peninsula, at the bottom of the most extensive and
complex water management system in the world. The Everglades ecosystem is
generally described as the Kissimmee/Okeechobee/ Everglades basin covering the
southern half of the State of Florida. Since the early 1900s, water levels are
estimated to have been lowered as a result of drainage throughout the Everglades by
as much as four to six feet. Since the 1950s, these changes have accelerated with
urban development and agribusiness expansion. As a result of these hydrological
changes, aquatic food chains in many parts of the Everglades have collapsed
resulting in serious declines in the number of wading birds, imperiling many
threatened and endangered species, and contributing to the decline of the Florida
Bay, the Florida Keys National Marine Sanctuary, and coastal estuaries.
• National Park Service Organic Act ol 1916. The purpose of this Act, which
created NFS, is to "conserve the scenery and the natural and historic objects
and the wildlife therein and to provide for the enjoyment of the same in such
manner and by such means as will leave them unimpaired for the enjoyment
of future generations..."
• Wild and Scenic Rivers Act of 1968.The goal of the Wild and Scenic Rivers
Act is to protect outstanding natural free-flowing rivers from damming and
other forms of development. NFS is responsible for managing all designated
river segments, except those managed by states, the Forest Service, or the
Bureau of Land Management. The Act also encourages river protection by
authorizing the Secretary of the Interior to provide technical assistance to
state and local governments and to private interests in support of the law's
objectives. Many state programs have benefited from this assistance.
Minerals Management Service (MMS)
MMS studies the potential impact of offshore activities, including the placement
and construction of petroleum pipelines, on coastal wetlands and resources. MMS
also funds research through state geoscience agencies for identifying mineral
resources in the coastal zone.
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U.S. Geological Survey (USGS)
The mission of the USGS, Water Resources Division, is to provide the hydrologic
information and understanding needed for the optimum utilization and
management of the nation's water resources for the overall benefit of the people of
the U.S. USGS conducts research on the geologic framework of coasts and on
sediment-transport processes; collects and analyzes hydrologic data; makes
topographic, geologic, and hydrologic maps of coastal areas; and investigates ancient
and modern coastal environments. Scientific studies of sedimentary processes and
seismicity traditionally have been part of the USGS mandate, and recently, Congress
directed USGS to take the lead in geologic studies of the coastal zone and wetlands
by creating a National Coastal Geology Program. Areas of study include erosion,
polluted sediments, and wetlands deterioration.
• The Water Resource Research Act of 1984. This Act established a Water
Resource Institutes or Center in each of the 50 states. These are mandated by
federal law to: 1) provide centers of expertise in water and associated land-use
problems and serve as a repository of knowledge for use in education,
research, planning, and community service, 2) serve public and private
interests in the conservation, development, and use of water resources,
3) provide training opportunities in higher education, whereby skilled
professionals become available to serve government and the private sector,
4) assist planning and regulatory bodies at the local, state, regional, and federal
levels, and 5) communicate research findings to potential users in a form that
encourages quick comprehension and direct application to a water-related
problem.
Many of the centers and institutes also have mandates in state law to assist
state agencies in state water management and to facilitate and stimulate
planning and management that deals with water policy issues. These are
funded by grants from USGS, but guided by a set of state level priorities. The
following institutes are located in the Gulf States: Alabama Water Resources
Research Institute, Florida Wetlands and Water Resources Research Center,
Louisiana Water Resources Research Institute, Mississippi Water Resources
Research Institute, and the Texas Water Resources Institute.
Federal Energy Regulatory Commission (FERC)
• Federal Power Act of 1986 (as amended). This Act provides for FERC to
license hydropower facilities. The amendments require FERC to incorporate
fish and wildlife concerns in licenses and exemptions for hydropower
facilities.
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STATE LEVEL
Alabama
Coastal Zone Management. The Alabama Coastal Zone Management (CZM)
Program was established in 1979 as a result of the need to implement the Coastal
Zone Management Act, P.L. 92-583, passed by Congress in 1972. This legislation was
initiated to improve the management of the nation's coastal area. The Alabama
Coastal Program has been revised throughout its existence since 1979 to
accommodate changes in coastal zone management policy.
A major function of the CZM program is resource protection. This encompasses a
multitude of coastal resource issues such as recreation, shoreline erosion,
commercial and recreational fishing, water quality, air quality, wetland protection,
wildlife protection, industrial and urban development, hazard management, etc.
The responsibilities of the Alabama Coastal Zone Management Program are divided
between two state agencies: the Alabama Department of Economic & Community
Affairs (ADECA) and the Alabama Department of Environmental Management
(ADEM).
Alabama Department of Economic & Community Affairs (ADECA). ADECA's role
is to act as the lead agency responsible for overall management of the program
including administration and planning, fiscal management, grants management,
and public education and information.
The Alabama Department of Environmental Management (ADEM). ADEM has the
authority to develop and enforce regulations affecting streamflow to the Gulf of
Mexico. Water quality certification is the basic regulatory tool of ADEM and is
required for certain projects in the Alabama coastal zone including dredging and
filling work, bulkhead construction, jetty construction, shoreline maintenance, and
other development projects. ADEM coordinates with the USAGE on approval of
Section 404 permits which are required for dredging activities and filling in
wetlands. ADEM also makes determinations for consistency with the Alabama
Coastal Zone Management Program.
In addition, the agency tracks water quality trends and presently has twenty-seven
water quality monitoring stations located in Mobile and Baldwin counties, primarily
on tributaries to Mobile Bay.
Current & Future Alabama Coastal Zone Management Planning Activities.
Public Education. ADECA, acting as the lead agency .and in conjunction with ADEM,
USACE, and several other agencies comprised the Alabama Steering Committee for
"Year of the Gulf" Activities. A new event was created called "Mobile Bay Day,
What a Difference a Bay Makes!" The event was held in April of 1993 and attracted
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many participants and interested individuals and received much attention by the
media.
These public education activities also served as the catalyst for the creation of the
Alabama Coastal Foundation (ACF). This organization is dedicated to the conservation of
the natural and economic resources of the Alabama coastal area. ACF serves as a
proponent for many coastal activities including the Alabama Coastal Clean-up,
Boater's Pledge, and Amnesty Day. The foundation also has future plans to publish
a Coastal Newsletter.
During the past few years both Baldwin and Mobile Counties have experienced
severe erosion in a few isolated areas such as Little Lagoon Pass and Dauphin
Island's main beach. The CZM Program is presently formulating a comprehensive
Shoreline Management Plan which will include: 1) a technical evaluation of past
and projected erosion; 2) an economic evaluation of the value of Alabama's Gulf
beaches, and 3) an identification of goals and objectives for shoreline management,
management procedures, and funding sources.
Florida
Water Quantity & Quality. In Florida, several state, regional, and local regulatory
and planning programs have effects on the quantity, quality, and timing of
freshwater inflow to estuaries. The Department of Environmental Protection (DEP),
recently formed by the consolidation of two agencies, regulates sources of potential
water pollution under the general requirements of FLA. STAT. § 403.087. The
wetlands permitting program is jointly administered by DEP and the state's five
water management districts. It applies to dredge and fill activities occurring in
surface waters to their landward extent, as defined by hydric soils and vegetation
[FLA. STAT. § 373.414 (1993)]. The state program requires the project applicant to
provide reasonable assurance that water quality standards will be met and that the
project is not contrary to the public interest or, if it is in or significantly degrades an
Outstanding Florida Water, that it is clearly in the public interest (Ibid).
The permitting agency is required to "consider and balance" a number of criteria in
making the public interest determination, including, among others: adverse effects
on the conservation of fish and wildlife, including endangered or threatened
species, or their habitats; adverse effects on navigation or the flow of water or
harmful erosion or shoaling; and adverse effects on fishing or recreational values or
marine productivity in the vicinity [FLA. STAT. §373.414 (1993)]. Cumulative impacts
must be considered, and if a proposed project is otherwise unable to meet the public
interest test, DEP is required to consider mitigative measures that are "proposed by
or acceptable to" the applicant (Ibid). The legislation also requires that estuaries be
protected from inappropriate shoreline armoring. Activities such as drainage,
harvesting, changing or obstructing water flow, and polluting are not specifically
subject to wetland regulation.
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The wetlands permitting program will be altered under recently adopted state
legislation. By July 1, 1994, the new DEP is required to adopt rules for the
consolidation of dredge and fill, management and storage of surface waters, storm
water, and mangrove alteration regulations into a single permit to be known as the
"environmental resource permit." Additionally, after legislative ratification in
1994, a statewide wetland delineation methodology, including regional variations,
will supersede all existing approaches at the state, regional, and local level [FLA.
STAT. § 373.421 (1993)]. By December 1,1994, DEP must adopt rules for the delegation
of the permitting program to local governments and pollution control authorities
[FLA. STAT. § 373.441 (1993)].
Florida's five regional water management districts are responsible for the regulation
of agricultural water management under the management and storage of surface
water (MSSW) section of Chapter 373, Florida Statutes [FLA. STAT. § 373.403 et. seq. ]
Generally, district rules require that MSSW systems not adversely affect surface and
groundwater levels; however, many agricultural activities and impacts are exempt
from water management district regulation unless the activity is for the sole or
predominant purpose of impounding or obstructing surface waters. The section
also exempts an agricultural "closed system," located entirely within agricultural
lands owned or controlled by the user and which require only filling, replenishing,
and maintaining the water level [FLA. STAT. § 373.403(6)]. The districts are
authorized to regulate activities in isolated wetlands, but only if the wetland is
larger than 0.2 hectares (0.5 acres).
The permitting of consumptive use of surface and ground water is carried out by the
water management districts and includes conditions on permits to ensure the use is
"consistent with the overall objectives of the district" and "not harmful to the water
resources of the area." FLA. STAT. § 373.219(1) (1991). The applicant must establish
that the proposed use is "reasonable-beneficial," will not interfere with any
presently existing legal use of water, and is consistent with the public interest.
["Reasonable-beneficial" means the use of water in such quantity as is necessary for
economic and efficient utilization for a purpose and in a manner which is both
reasonable ad consistent with the public interest. FLA. STAT. § 373.019(4) (1991).] The
general permit criteria requiring reasonable-beneficial use and consistency with the
public interest incorporate consideration of ecosystem needs.
The districts are also authorized to reserve water from use by permit applicants for
the protection of fish and wildlife [FLA. STAT. § 373.223(3) (1991)]. The districts are
required to establish minimum flows for watercourses and minimum levels for
surface waters and aquifers [FLA. STAT. § 373.042 (1991)]. Minimum flows are limits
at which further withdrawals would be "significantly harmful to the water resources
or ecology of the area." Minimum levels are limits at which further withdrawals
would be "significantly harmful to the water resources of the area" (Ibid). Generally,
these requirements have not been met. In addition, district water shortage rules
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Federal & State Framework
Appendix A
control when water shortages will be declared and what restrictions may be imposed
on water use [FLA. STAT. § 373.175 (1991)].
Some of the most important planning responsibilities of the water management
districts are those required by the district water management planning (DWMP)
process [FLA. ADMIN. CODE r. 17-40.501 (1991)], and the Surface Water Improvement
and Management (SWIM) Act [FLA. STAT. §§ 373.451-373.4595 (1991)]. Draft DWMPs
were recently completed, with final DWMPs due in late 1994. Areas of planning.
responsibility are water supply, including analyses of needs and sources and source
protection; flood protection, including analyses of facilities and flood prone areas;
water quality management for both surface and ground water; and natural systems
management, including analyses of ecosystem needs and minimum flows and
levels.
The state's SWIM Act requires the districts to establish a list of prioritized surface
waters and to develop plans for the restoration and maintenance of water quality in
those waters. Many of Florida's estuaries bordering the Gulf of Mexico have been
included in the planning process. Though consideration of the quantity and timing
of freshwater inflow is not specifically required by the Act, most, districts recognize
the importance of the issue and have addressed it to varying degrees in the relevant
SWIM plans.
The districts are also required to provide technical assistance to local governments
on planning issues for water resources. Under the state's Growth Management Act
[FLA. STAT. §§ 163.3161-163.3215 (1991)], local governments must prepare
comprehensive plans addressing many aspects of growth, development, and
resource protection. L,ocal regulations must be consistent with the relevant plan
elements. The coastal management element requires analysis of existing and
proposed development of coastal resources and an analysis of the impact of drainage
systems and point and nonpoint source pollution on estuarine water quality.
Coastal Zone Management. The Florida Coastal Management Program (FCMP) was
approved by NOAA in 1981. The program revolves around the authorities of
twelve agencies and is guided by the Coastal Resources Interagency Management
Committee (IMC) composed of the Secretaries of these agencies. The agencies
include the following:
Department of Community Affairs
Department of Environmental Regulation
Department of Natural Resources
Department of Commerce
Department of Labor & Employment Security
Department of Transportation
Department of Health & Rehabilitative Services (Division of
Environmental Health)
Department of Agriculture & Consumer Services (Division of Forestry)
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Federal & State Framework
Appendix A
• Marine Fisheries Commission
• Game & Fresh Water Fish Commission
• Department of State (Division of Historical Resources)
• Governor's Office of Planning & Budgeting
The Chair of the Citizens Advisory Committee on Coastal Resources (CAC) also sits
on the IMC. The members of CAC are appointed by the Governor to represent
various interests in the coastal area, including local government, commercial
fishing, recreational fishing, citizens at large, coastal development, conservation,
energy, and environmental education.
IMC, with the assistance of CAC, identifies pressing coastal issues, conducts studies
of the issues, and proposes policy changes to address them. They advise the
Legislature, Governor, and Cabinet of their recommendations for action.
Since 1992, the lead agency for the FCMP has been the Department of Community
Affairs. The lead agency coordinates a network of state agencies, regional groups,
such as the water management districts and regional planning councils, and local
governments to implement the program. One of the key functions of the lead
agency is to help identify the appropriate parties for implementation of the goals of
IMC.
Under an annual work plan, the program distributes funding to the participating
groups for projects that implement the IMC's coastal action plan. The program also
reviews federal projects and permits for consistency with the enforceable policies of
the participating state agencies.
Louisiana
Coastal Zone Management. The State & Local Coastal Resources Management Act
(SLCRMA) La. R.S. 49:21, was passed by the Louisiana Legislature in 1978 and
received federal approval in October 1980. Presently the program is being
administered by the Coastal Management Division (CMD) within the Office of
Coastal Restoration and Management, Department of Natural Resources (DNR).
The Coastal Management Division of the Department of Natural Resources is
charged with implementing the Louisiana Coastal Resources Program (LCRP).
LCRP attempts to protect, develop, and restore or enhance the resources of the
state's coastal zone. Its broad intent is to encourage multiple uses of resources and
adequate economic growth while minimizing adverse effects of one resource upon
another without imposing undue restrictions on any user.
CMD's regulatory responsibilities include administering the Coastal Use Permit
(CUP) Program, the Consistency Program, and the Enforcement Program. The
Coastal Use Permit is the basic regulatory tool of CMD and is required for certain
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Appendix A
projects in the coastal zone, including, but not limited to, dredge and fill work,
bulkhead construction, shoreline maintenance, and other development projects.
CMD has processed about 15,500 CUP applications since the inception of the
program.
The Consistency Program requires activities of all federal and some state
governmental agencies to be consistent with LCRP. Particular attention is given to
environmental, economic, and cultural concerns. Most federal agencies conduct
their own consistency determination and, if projects are found to be inconsistent
with state regulations, they are not pursued. Examples of projects requiring a
consistency determination are hurricane protection levees; USAGE maintenance,
dredging, locks, and drainage structures; navigation projects; freshwater diversions;
and beach restoration projects.
The Enforcement & Monitoring Program ensures that any unauthorized projects in
the coastal zone are investigated and action is taken. The program also monitors
activities permitted by the CUP Program for compliance with permit conditions.
The program gives the secretary of DNR the authority to enforce either legal or
administrative procedures including fines, cease and desist orders, and restorative
or mitigation work. The field investigative staff regularly monitors the entire
coastal area for unauthorized activities and for non-compliance with permit
conditions.
During the Second Special Session of 1989, the Louisiana Legislature passed Act 6,
which requires the State of Louisiana to annually develop a Coastal Wetlands
Conservation and Restoration Plan from both a short and long range perspective.
The initiative for passing Act 6 was provided when it passed a voter referendum by
approximately 75 percent.
The Coastal Restoration Division has the responsibility for implementing the Plan,
which is designed to restore, preserve, and enhance Louisiana's coastal wetlands.
The plan is the result of over 25 years of research and involves many innovative
techniques designed to work with nature. The plan is an evolving one and includes
a large number of individual projects which are designed to meet specific needs.
Current restoration techniques include freshwater diversion, sediment diversion,
marsh management, sediment capturing, shallow bay terracing, and structural
shoreline erosion abatement devices.
Mississippi
Water Quantity and Quality. The Mississippi Department of Environmental
Quality (MDEQ) has the authority to regulate the use of surface and ground waters
in Mississippi. The statutes providing MDEQ with this authority are codified in
Title 51, Chapter 3, of the Mississippi Code of 1972. MDEQ is also charged with
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regulating the quality of marine and fresh waters in Mississippi. This-authority is
located in Title 49, Chapter 17, of the Mississippi Code of 1972.
Projects Affecting Freshwater Inflows. The Mississippi Commission of Wildlife,
Fisheries, and Parks is authorized in Title 49, Chapter 15, Section 15(6), of the
Mississippi Code of 1972 to "support projects in the nature of digging or constructing
canals or ditches in order to bring additional water to existing oyster reefs" or to
establish new oyster reefs. The Commission is authorized to spend monies and
enter into interstate agreements as it deems appropriate and necessary for freshwater
diversion projects. Up to three million dollars was authorized for expenditure on
the Mississippi and Louisiana Estuarine Areas Project in 1989 by the Mississippi
Legislature for the purposes of constructing a freshwater diversion canal with
Louisiana and the USAGE (Title 57, Chapter 61, Section 32, in the Mississippi Code
of 1972).
Coastal Zone Management. The Mississippi Coastal Program was approved by the
Commission on Wildlife Conservation on August 22, 1980, and has been updated
throughout its implementation. This program is built around ten goals for guiding
decisions affecting the development of Mississippi's coastal resources. These goals
include, but are not limited to the following:
• Providing for reasonable industrial expansion in the coastal area and
insuring the efficient utilization of waterfront industrial sites so that
suitable sites are conserved for water dependent industry.
• Favoring the preservation of the coastal wetlands and ecosystems, except
where a specific alteration of a specific coastal- wetlands would serve a
higher public interest in compliance with the public purposes of the
public trust in which the coastal wetlands are held.
• Encouraging the preservation of natural scenic qualities in the coastal
area.
• Considering the national interest involved in planning for and in the
siting of facilities in the coastal area.
The agencies responsible for the Coastal Program are the Bureau of Marine
Resources, the Bureau of Pollution Control, the Bureau of Land and Water
Resources, and the Department of Archives and History. These four agencies are
responsible for monitoring state and federal decisions that affect the coastal area and
for ensuring that such decisions are made in accordance with program councils.
The Bureau of Marine Resources (BMR) is the lead agency responsible for the
overall administration of the coastal program. This agency regulates projects and
activities under the Wetlands Protection Law and saltwater fisheries statutes. There
are three types of activities regulated under BMR's jurisdiction. These are activities
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Appendix A
physically located in coastal wetlands (i.e., piers, bulkheads), those not located in the
coastal wetlands but affecting them by indirect means (i.e., construction), and the
erection of structures on sites suitable for water dependent industry.
Development is directly regulated to minimize adverse impacts. This is done by
addressing special management areas (SMA). SMAs detail all regulations affecting
an area and specifically state what will and will not happen in an area, thus
ensuring that development will occur in a predictable manner.
Texas
Texas Natural Resource Conservation Commission (TNRCC). The Texas Natural
Resource Conservation Commission (TNRCC) has the responsibility of protecting
surface and groundwater quality. In addition to this responsibility, the Commission
oversees surface water rights administration, dam safety management, the National
Flood Insurance Program and flood control improvement project administration,
injection well program administration, waste minimization initiatives, and water
district supervision. (Effective September 1, 1993, the Texas Water Commission was
combined with the Texas Air Control Board to form the Texas Natural Resource
Conservation Commission.)
TNRCC has the authority to develop/enforce regulations affecting streamflow to the
Gulf. These regulations are contained in Chapters 11.147 and 11.152 of the Texas
Water Code. The 69th Texas Legislature assigned the responsibility for water rights
permitting to TNRCC and gave the Texas Parks and Wildlife Department (TPWD)
authority to be a party in hearings on applications for permits to store, take, or divert
water—actions that can change the pattern or quantity of freshwater inflow. The
Legislature directed TNRCC to consider effects on bays and estuaries for all water
rights permits, with a specific directive to include protective provisions in certain
permits by applying a performance standard when making decisions concerning
water rights on rivers and streams leading to bays and estuaries.
Texas Water Development Board (TWDB). The Texas Water Development Board
(TWDB) is the state agency responsible for planning, financing, and developing
water and wastewater projects. TWDB was created in 1957 by acts of the 55th Texas
Legislature, and its duties and responsibilities have been increased by subsequent
legislative sessions and constitutional amendments. Statutory authority, specifically
for the freshwater inflow needs assessment of Texas bays and estuaries, was
expanded by acts of the 69th Legislature in 1985. TWDB's authority under state
statutes is found in Chapters 6 and 15-20 of the Texas Water Code.
TWDB's mission is to provide state leadership in the conservation and responsible
development of water resources for current and future generations of Texans, their
economic well-being, and their quality of life. One of TWDB's primary goals is to
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plan and provide financial assistance for water supplies of sufficient high quality for
human use and for maintenance and enhancement of the natural environment.
The reservation and optimization of freshwater inflows, as well as the beneficial use
of wastewater return flows, are important features of watershed protection and the
ecological enhancement of wetlcinds associated with bays and estuaries which will
further TWDB's ability to meet its goals for Texas. The 69th Legislature also directed
TWDB and TPWD to establish and maintain a continuous data collection and
evaluation program and conduct studies and analyses aimed at determining bay
conditions that provide a sound ecological environment.
Funding for TWDB activities comes primarily from state general revenues, federal
programs, and capitalization grants which finance the State Revolving Fund for
construction of wastewater treatment plants. TWDB's financing of public water
projects and the freshwater inflow studies also involve the Texas Water Assistance
Fund, the Texas Water Development Bond Program, and the Texas Water
Resources Finance Authority.
Texas Parks & Wildlife Department (TPWD). The Texas Parks & Wildlife
Department (TPWD) operates the state parks system and wildlife refuges, A permit
must be obtained from TPWD for the disturbance or dredging of sand, shell, or marl
in public waters not authorized by other state or federal agencies. Public waters are
defined as all the salt and fresh waters underlying the beds of navigable streams
under the jurisdiction of the Parks & Wildlife Commission. TPWD is responsible
for reviewing and commenting on state and federal permits affecting Texas wildlife
resources and protecting endangered or threatened species.
Texas General Land Office (GLO). The Texas General Land Office (GLO), in
conjunction with the School Land Board, manages the state's coastal public lands.
GLO has developed a coastal management plan for Texas beaches and the state-
owned submerged land underlying the Gulf of Mexico. On June 7,1991, the Texas
State Legislature passed two bills creating a State-Owned Wetlands Conservation
Plan and a Coastal Management Plan addressing coastal erosion, beach access, dune
protection, and planning and coordination of these activities. Texas recently
submitted a coastal management plan for approval under the federal Coastal Zone
Reauthorization Act.
The Commissioner of GLO may issue permits for geological, geophysical, and other
investigations within the tidewater limits of the state. The Commissioner may also
grant easements or leases for rights-of-way across state lands for pipelines and other
transmission lines.
School Land Board. The School Land Board, in conjunction with GLO, manages the
state's coastal public lands. The Board may grant leases to certain governmental
bodies for public purposes; leases for mineral exploration and development;
easements to littoral landowners; channel easements to surface or mineral interest
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Fodoral & Stato Framework
Appendix A
holders; leases to educational, scientific, or conservation interests; and permits for
limited use of previously unauthorized structures.
Soil & Water Conservation Board. The Texas State Soil & Water Conservation
Board has the responsibility to plan, implement, and manage programs and
practices for abating agricultural and silvicultural nonpoint pollution. The State
Board also administers a voluntary conservation program with and through 212
local soil and water conservation districts which encompass over 99 percent of the
surface acres of Texas. With a voluntary program, conservation practices are being
applied by over 215,000 cooperating landowners on more than 48.6 million hectares
(120 million acres).
Bay & Estuary Inflow Studies. In the 69th Legislative Session, and amended in the
70th Session, the Texas Legislature directed TWDB and TPWD to jointly establish
and maintain a continuous bay and estuary data collection and evaluation program
and to conduct studies and analyses for determining the bay conditions necessary to
support a sound ecological environment [Texas Water Code 16.058(1)]. The final
report will document the results of these studies on the effects of freshwater inflows
on the biological productivity of bays and estuaries, the distribution and abundance
of economically important and ecologically characteristic fish and shellfish species,
and the estuarine life upon which they depend.
In addition to documenting the importance of freshwater inflows, this report will
present an analytical method for determining freshwater inflow needs for Texas
estuaries [Texas Estuarine Mathematical Programming (TXEMP) Model]. The
procedure was designed to assist TNRCC in quantifying beneficial inflows that are
necessary for maintaining an ecologically sound environment.
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Federal & State Framework
Appendix A
REGIONAL LEVEL
Water Districts. Within the State of Texas, the Constitution provides for the
creation of water districts to address both local and regional issues associated with
the use, preservation, and protection of the state's water resources. The various
types of districts are created by either special law or general law and must comply
with the laws contained in the Texas Water Code and other applicable statutes. For
example, river authorities are special law districts that often encompass entire river
basins and reach into many counties. Most river authorities operate major
reservoirs and sell untreated water on a wholesale basis. They also may have
responsibility for flood control, hydropower, soil conservation, and water quality.
Many of the responsibilities delegated to river authorities and other types of water
districts may influence the amount and timing of freshwater inflows to coastal
waters.
River Authorities. There are 17 river authorities in Texas and their general
functions are to regulate streamflow in rivers and enforce regulations that have
effects on streamflow to the Gulf. The regulations generally involve River
Management Plans, Reservoir Operation Plans, and sewage treatment facilities. The
authorities for these regulations are included in Certificates of Adjudication, Water
Appropriations Permits, Orders, and Resolutions of the Texas Natural Resource
Conservation Commission.
Interstate Compacts. The State of Texas is party to five interstate compacts
involving the Rio Grande, Pecos, Red, Sabine, and Canadian Rivers. The compacts
are interstate agreements which equitably apportion the waters of each stream
between the compacting states. The compacts are administered by interstate
commissions which oversee the deliveries and use of water by the compacting
states. As an example, the Sabine River Compact Administration is composed of
Texas and Louisiana and administers water deliveries and diversions pursuant to
the terms of the Sabine River Compact. .
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Acronym Guide
Appendix B
ACAMP Alabama Coastal Area Management Program
ACF Alabama Coastal Foundation
ADECA Alabama Department of Economic & Community Affairs
ADEM Alabama Department of Environmental Management
AL Alabama
ATSDR Agency for Toxic Substances & Disease Registry
BMP Best Management Practice
BMR Bureau of Marine Resources—Mississippi
CAC Citizens Advisory Committee—Gulf of Mexico Program
CCMP Comprehensive Conservation & Management Plan
CMD Coastal Management Division—Louisiana
CUP Coastal Use Permit—Louisiana
CWA Clean Water Act
CWPPRA Coastal Wetland Planning, Protection & Restoration Act
CZM Coastal Zone Management
CZARA Coastal Zone Act Reauthorization Amendments
DEP Department of Environmental Protection—Florida
DNR Department of Natural Resources—Louisiana
DWMP District Water Management Planning—Florida
EIS Environmental Impact Statement
ESA Endangered Species Act
FCMP Florida Coastal Management Program
FERC Federal Energy Regulatory Commission
FL Florida
FWPCA Federal Water Pollution Control Act
GIS Geographic Information Systems
GLO General Land Office
GMP Gulf of Mexico Program
GMPO Gulf of Mexico Program Office
IBWC International Boundary & Water Commission
1C Issue Committee—Gulf of Mexico Program
IMC Interagency Management Committee—Florida
LA Louisiana
LADEQ Louisiana Department of Environmental Quality
LCRA Lower Colorado River Authority
LCRP Louisiana Coastal Resources Program
MC Management Committee—Gulf of Mexico Program
MDEQ Mississippi Department of Environmental Quality
MMS Minerals Management Service
MS Mississippi
MSSW Management & Storage of Surface Water-Florida Statutes
NAS National Academy of Science
NASA National Aeronautics & Space Administration
NEI National Estuarine Inventory
NEP National Estuary Program
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Acronym Guide
Appendix B
NEPA National Environmental Policy Act
NESDIS National Environmental Data & Information Service
NFIP National Flood Insurance Program
NMFS National Marine Fisheries Service
NOAA National Oceanic & Atmospheric Administration
NFS National Park Service ;
NRC National Research Council
NS&T National Status & Trends
NWS National Weather Service
OCS Outer Continental Shelf
ORCA Office of Ocean Resources Conservation & Assessment
PRB Policy Review Board—Gulf of Mexico Program
PSA Public Service Announcement
SAB Strategic Assessment Branch
SCS Soil Conservation Service
SEFSC Southeast Fisheries Science Center
SERO Southeast Regional Office—National Marine Fisheries Service
SLCRMA State & Local Coastal Resources Management Act—Louisiana
SMA Special Management Area
SWIM Surface Water Improvement & Management Act—Florida
TAC Technical Advisory Committee—Gulf of Mexico Program
TNRCC Texas Natural Resource Conservation Commission
TPWD Texas Parks & Wildlife Department
TV A Tennessee Valley Authority
TWDB Texas Water Development Board
TX Texas
TXEMP Texas Estuarine Mathematical Programming Model
USAGE U.S. Army Corps of Engineers
USCG U.S. Coast Guard
USDA U.S. Department of Agriculture
USDOC U.S. Department of Commerce
USDOD U.S. Department of Defense
USDOE U.S. Department of Energy
USDOI U.S. Department of the Interior
USDOT ? U.S. Department of Transportation
USEPA U. S. Environmental Protection Agency
USFDA U.S. Food & Drug Administration ,
USFWS U.S. Fish & Wildlife Service
USGS U.S. Geological Survey
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Glossary
Appendix C
aerobic
algae
algal blooms
ambient
anaerobic
anoxia
anthropogenic
aquifer
benthic
benthos
biochemical
oxygen demand
(BOD)
biota
biotic
community'
bloom
brackish
characterization
coastal runoff
coastal zone
compliance
Presence of free oxygen (oxygen gas).
Any of a group of aquatic plants, including phytoplankton and seaweeds,
ranging from microscopic to several meters in size.
Sudden spurs of algal growth, which can affect water quality adversely.
Often, excessive blooms indicate nutrient enrichment. Some species cause
potentially hazardous changes in local water chemistry.
Referring to average concentrations of substances in the surrounding media
(water, air, or sediment).
Absence of free oxygen (oxygen gas).
Absence of dissolved oxygen in water (<0.1 mg oxygen/L).
Relating to, or resulting from, the influence of human beings on nature.
An underground geological formation, or group of formations, containing usable
amounts of ground water that can supply wells and springs.
Of or pertaining to the bottom or near bottom of a stream, lake, or ocean.
All marine organisms (plant and animal) living on or near the bottom of the
sea.
A measure of the quantity of dissolved oxygen removed from water by the
metabolism of microorganisms. Excessive BOD results in oxygen-poor water.
Plants and animals inhabiting a given region.
A naturally-occurring assemblage of plants and animals that live in the same
environment and are mutually sustaining and interdependent.
Excessive growth of plankton in concentrations sufficiently dense to cause
discoloration of water and reduced light penetration.
Salty, but not as salty as sea water. Brackish water occurs in estuaries, creeks,
and deep wells.
The process of bringing together a number of information sources to synthesize
overall patterns or make a statement of current conditions.
Storm water and the materials it carries from land surrounding a coastal area.
Lands and waters adjacent to the coast that exert an influence on the uses of the
sea and its ecology, or inversely, whose uses and ecology are affected by the sea.
Legally, the definition varies from state to state.
Conformance to the rules and regulations regarding wastewater discharges.
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Glossary
Appondlx C
control program
controllable
criteria
cumulative
impacts
decomposition
dissolved oxygen
(DO)
drainage basin
dry weather
overflows
ecological impact
ecosystem
effluent
enrichment
estuary
freshwater
Geographic
Information
System (CIS)
The methods used to reduce nutrient releases from both point sources and
nonpoint sources.
Those sources of nutrients that arise or result from the impact of human
activities and are not attributable to background loads. "Controllable" does not
imply that these loads are scheduled for control or that they can all be
managed, only that they can be controlled given the technologies available.
Acceptable limits in various media (e.g., water, sediments) for pollutants
derived by USEPA. When issued by USEPA, the criteria provide guidance to
the states on how to establish their standards.
Combined effects resulting from more than one action.
The breakdown of matter by bacteria and fungi. It changes the chemical make-
up and physical appearance of materials being broken down and may cause
changes in the environment as well.
Concentration of oxygen in water, commonly employed as a measure of water
quality. Low levels adversely affect aquatic life. Most finfish cannot survive
when DO falls below 3 mg/L for a sustained period of time. SEE ANOXIA
AND HYPOXIA
The land area drained by a river or stream and its tributaries.
Illegal discharges of untreated wastewater from combined sewer overflows
and storm drains unrelated to rainfall events. During rainstorms such
discharges are referred to as "wet weather overflows."
The effect that a human or natural activity has on living organisms and their
non-living (abiotic) environment.
An ecological community consisting of living organisms and their physical and
chemical environment.
Discharge or emission of a liquid or gas, usually from a point source (e.g., pipe or
stack), into the environment.
The addition of nutrients (e.g., nitrogen, phosphorus, carbon compounds) from
sewage effluent, runoff> or atmospheric deposition to surface water. This
process greatly increases the growth potential for algae and aquatic plants.
A semi-enclosed body of water, connected to the open sea, in which sea water is
measurably diluted with freshwater from inland sources.
Water that generally contains less than 1,000 milligrams-per-liter of dissolved
solids. -
A computerized database of land use, land cover, and many other types of
information that can be statistically analyzed and graphically displayed
using maps.
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Glossary
Appendix C
ground water
habitat
hydrodynamic
hypoxia
land use
living resources
loading
marine
meteorological
conditions
mitigate
model
modeling
monitoring
National
Pollutant
Discharge
Elimination
System (NPDES)
nitrogen
nonpoint source
pollution
NPDES permits
Subsurface water saturating soil or porous rock which often returns, with its
nitrogen loads, to surface streams during dry periods.
The place where a population (e.g., human, animal, plant, microorganism)
lives and its surroundings, both living and non-living.
Concerning the forces, energy, and pressure of water in motion.
Low levels of dissolved oxygen in water, defined as less than 2 mg/L.
Refers to the ways in which a community or area makes use of its natural
resources.
Plant and animal life.
Quantity of contaminants, nutrients, or other substances introduced into a
waterbody.
Pertaining to the ocean or sea.
Atmospheric phenomena, such as precipitation, wind, and temperature,
which ultimately drive the surface and groundwater flow of water and
nutrients.
To make less serious or severe.
A simplified mathematical representation of reality. Water quality modeling
is used to study Gulf of Mexico processes and project effects of varying
environmental conditions or management actions.
An investigative technique using a mathematical or physical representation of
a system or theory, usually on a computer, which accounts for all or some of its
known properties. Models are often used to test the effect of changes of system
components on the overall performance of the system.
Observing, tracking or measuring some aspect of the environment to establish
base line conditions and short or long-term trends.
A provision of the Clean Water Act that prohibits discharge of pollutants into
waters of the U.S. unless a special permit is issued by USEPA, state, or (where
delegated) a tribal government on an Indian reservation.
A nutrient essential for life. May be organic or inorganic (ammonia, nitrate,
nitrite). Elemental nitrogen constitutes 78 percent of the atmosphere by volume.
Toxicants, other contaminants, nutrients, or soil entering a waterbody from
sources other than discrete discharges, such as pipes. Includes pollution on the
land which originates as atmospheric deposition, as well as farm and urban
runoff.
National Pollutant Discharge Elimination System Permits to discharge treated
wastewaters to the waters of the U.S. issued by either USEPA or the state.
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Glossary
Appendix C
nutrients
nutrient
enrichment
organic
organic matter
organism
oxygen demand
permit
phosphorus
phytoplankton
point source
pollution
pollutant
pollution
productivity
qualitative
quality assurance/
quality control
(QA/QC)
quantitative
receiving waters
Chemicals required for growth and reproduction of plants. Excessive levels of
the nutrients nitrogen and phosphorus can lead to excessive algae growth.
Nutrient enrichment increases primary productivity in a waterbody,
eventually resulting in depletion of dissolved oxygen essential to aquatic life
(also called eutrophication).
(1) Referring to or derived from living organisms. (2) In chemistry, any
compound containing carbon.
Carbonaceous waste contained in plant or animal matter and originating from
domestic or industrial sources.
Any living thing.
Consumption of oxygen by bacteria to oxidize organic matter.
An authorization, license, or equivalent control document issued by USEPA or an
approved state agency to implement the requirements of an environmental
regulation, e.%., permit to discharge from a wastewater treatment plant or to
operate a facility that may generate harmful emissions.
A nutrient essential for life found in both organic and inorganic forms.
Microscopic plants that live in water such as algae.
Contamination from waste effluent discharged into a waterbody through pipes
or conduits.
Generally, any substance introduced into the environment that adversely
affects the health of plants and animals, or the usefulness of a resource.
Generally, the presence of matter or energy whose nature, location, or quantity
produces undesired environmental effects. Under the Clean Water Act, for
example, the term is defined as the man-made or man-induced alteration of the
physical, biological, and radiological integrity of the water.
Process by which plants remove dissolved carbon dioxide and micro-nutrients
from the water and, using solar energy, convert them to complex organic
compounds of high potential energy.
Pertaining to the non-numerical assessment of a parameter.
A system of procedures, checks, audits, and corrective actions to ensure that
research design and performance, environmental monitoring and sampling, and
other technical and reporting activities are of the highest achievable quality.
Pertaining to the numerical assessment of a parameter.
A river, lake, ocean, stream, or other watercourse into which wastewater or
treated effluent is discharged.
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Glossary
Appendix C
residual
restoration
runoff
salinity
sediments
standards
storm water
stratification
stream
surface water
toxic
tributary
turbidity
wastewater
water clarity
water column
water qualify
Amount of a pollutant remaining in the environment after a natural or
technological process has taken place, e.g., the sludge remaining after initial
wastewater treatment, or particulates remaining in air after the air passes
through a scrubbing or other pollutant removal process.
The act of returning something such as habitat or water quality to its condition
prior to human disturbance. Measure taken to return a site to natural conditions.
•g
Drainage of precipitation over the soil or a non-porous surface (e.g., asphalt) to
a stream, river, or other receiving body of water.
Amount, by weight, of dissolved salts in 1,000 units of water (reported as
parts/thousand).
The loose solids, (e.g., soil from erosion or runoff) that settle to the bottom of a
waterbody or its tributaries which can be sources of nitrogen and phosphorus.
Prescriptive norms that govern action and actual limits on the amount of
pollutants or emissions produced. USEPA, under most of its responsibilities,
establishes minimum standards. States can issue stricter standards if they
choose.
Runoff caused by precipitation.
The layering of fresh water over salt water due to differences in relative
density and temperature.
A body of water, including brooks and creeks, that moves in a definite channel
in the ground driven by a hydraulic gradient.
All water naturally open to the atmosphere (rivers, lakes, reservoirs, streams,
impoundments, seas, estuaries, etc.); also refers to springs, wells, or other
collectors that are directly influenced by surface water.
Harmful to living organisms.
A stream, creek, or river that flows into a larger stream, creek or river.
Reduction of water clarity caused by suspended sediments and organics in the
water.
The spent or used water that contains dissolved or suspended matter from
individual homes, a community, a farm, or an industry.
A general term which describes the transparency of water in an aquatic system.
Water clarity is reduced with increased amounts of particulate materials (e.g.,
suspended sediments) in the water column. SEE LIGHT ATTENUATION
A vertical extent of water reaching from the surface to the bottom substrate of a
waterbody.
Status or condition of a waterbody in terms of defined variables characterizing
the "health" of the water.
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Glossary
Appendix C
water quality
standards
watershed
wetlands
zooplankton
State-adopted and USEPA-approved ambient standards for waterbodies.
The standards cover the use of the water body and the water quality criteria
that must be met to protect the designated use or uses (e.g., drinking, swimming,
fishing).
Land area from which precipitation drains into a given body of water.
An area that is regularly saturated by surface or ground water and subsequently
'is characterized by a prevalence of vegetation that is adapted for life in soil
conditions. Examples include: swamps, bogs, fens, and marshes. Often defined
based on soil characteristics.
Animal plankton of widely varying size that drift or swim weakly in the
water. They consume the primary producers and are a second link in the food
chain or food web.
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Participants In the Action Agenda Development Process
Appendix D
The Freshwater Inflow Committee
Co-Chairs:
Susan Rees
Bruce Moulton
U.S. Army Corps of Engineers
Texas Natural Resource Conservation Commission
Members:
Len Bahr*
Joan Browder*
Fred Deegen*
Dick Eckenrod*
Ernie Estevez
David Hankla
Dave Smith
John Klein
Larry Land
Fritzi Pikes
Don Waller
Janet Starnes
Walter Stevenson, Jr.
Lon Strong*
John Weber
Louisiana Office of the Governor
National Marine Fisheries Service
Mississippi Bureau of Marine Resources
Tampa Bay National Estuary Program
Mote Marine Laboratory
U.S. Fish & Wildlife Service
U.S. Fish & Wildlife Service/Gulf of Mexico Program
National Oceanic & Atmospheric Administration
U.S. Geological Survey
Texas Natural Resource Conservation C6mmission--CAC
Mississippi Farm Bureau Federation~CAC
Northwest Florida Water Management District
Alabama Department of Economic & Community Affairs
U.S. Soil Conservation Service
U.S. Army Corps of Engineers
*Steering Committee Member
Written Comments on Strawman Documents Received From the Following;
Joan Browder
Fred Deegen
Dick Eckenrod
Ernie Estevez
Bruce Moulton
National Marine Fisheries Service
Mississippi Bureau of Marine Resources
Tampa Bay National Estuary Program
Mote Marine Laboratory
Texas Natural Resource Conservation Commission
Florida Defenders of the Environment
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Participants in the Action Agenda Development Process
Appendix D
Participants in Action Agenda Workshop-April 15-16. 1993
Neil Armingeon
Len Bahr*
Alan Ballard
Sam Becker
Joan Browder*
Richard Browning
Ralph Cantral
Fred Deegen*
Carlton Dufrechou
Dick Eckenrod*
Ernest Estevez*
Sid Flannery
Larry Goldman
Jim Greenfield
Bill Holland
Charles Hunsicker
Bob Hutson
Ken Jones
Richard Kesel
John Klein*
Doug Lipka
Cindy Loeffler
Quentin Martin
Benjamin McPherson
Bruce Moulton*
Mark S. Peterson
Jonathan Pote
Gary Powell
Drew Puffer
Jim Ratterree
Susan Rees*
Michael Rozengurt
Frank Shipley
Judy Stout
Jeff Wade
John Weber*
Lake Pontchartrain Basin Foundation
Louisiana Office of the Governor
USEPA/Gulf of Mexico Program
U.S. Environmental Protection Agency—Region 6
National Marine Fisheries Service
Trinity River Authority
Florida Department of Community Affairs
Mississippi Department of Wildlife Conservation
Lake Pontchartrain Basin Foundation
Tampa Bay National Estuary Program
Mote Marine Laboratory
Southwest Florida Water Management District
U.S. Fish & Wildlife Service
U.S. Environmental Protection Agency—Region 4
USEPA/Gulf of Mexico Program
Manatee County Public Works Department
Mississippi Farm Bureau Federation
Northwest Florida Water Management District
Louisiana State University
National Oceanic & Atmospheric Administration
USEPA/Gulf of Mexico Program
Texas Parks & Wildlife Department
Lower Colorado River Authority
U.S. Geological Survey
Texas Natural Resource Conservation Commission
Mississippi State University
Mississippi Water Resources Research Institute
Texas Water Development Board
USEPA/Gulf of Mexico Program
U.S. Environmental Protection Agency—Region 6
U.S. Army Corps of Engineers
County Sanitation Districts of Orange County
Galveston Bay National Estuary Program
University of South Alabama
University of Florida
U.S. Army Corps of Engineers
*Freshwater Inflow Committee Member
Gulf of Mexico Freshwater Inflow Action Agenda (3.1)
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Participants In the Action Agenda Development Process
Appendix D
Comments on Draft Action Agenda f2.1l Received From the Following:
Len Bar
Joan Browder
Ralph Cantral
Sid Flannery
Doug Jacobson
John Klein
Myron Knudson
Andreas Mager, Jr.
Kumar Mahadevan
Brandt Mannchen
Bruce Moulton
J. Rogers Pearcy
Rogelio Perez
Jonathan Pote
Susan Rees
John Weber
Louisiana Office of the Governor
National Marine Fisheries Service
Florida Coastal Management Program
Southwest Florida Water Management District
U.S. Environmental Protection Agency—Region 6
National Oceanic & Atmospheric Administration
U.S. Environmental Protection Agency—Region 6
National Oceanic & Atmospheric Administration
Mote Marine Laboratory
Sierra Club
Texas Natural Resource Conservation Commission
Minerals Management Service
U.S. Fish and Wildlife Service
Mississippi Water Resources Research Institute
U.S. Army Corps of Engineers
U.S. Army Corps of Engineers
Gulf of Mexico Freshwater Inflow Aetlon Agenda (3.1)
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