Coast 2050: Toward a Sustainable Coastal Louisiana...Coast 2050: Toward a Sustainable Coastal Louisiana, The Appendices. Suggested citation: Louisiana Coastal Wetlands Conservation

COAST 2050

Federal State LocalPARTNERSHIP

Coast 2050: Toward a SustainableCoastal Louisiana

Louisiana Coastal Wetlands Conservationand Restoration Task Forceand theWetlands Conservation and RestorationAuthority

COAST 2050

Federal State LocalPARTNERSHIP

This document is one of three that outline a jointly developed, Federal/State/Local, planto address Louisiana’s massive coastal land loss problem and provide for a sustainablecoastal ecosystem by the year 2050. These three documents are:

! Coast 2050: Toward a Sustainable Coastal Louisiana,

! Coast 2050: Toward a Sustainable Coastal Louisiana, An Executive Summary,

! Coast 2050: Toward a Sustainable Coastal Louisiana, The Appendices.

Suggested citation: Louisiana Coastal Wetlands Conservation and Restoration Task Force and the WetlandsConservation and Restoration Authority. 1998. Coast 2050: Toward a Sustainable Coastal Louisiana. Louisiana Department of Natural Resources. Baton Rouge, La. 161 p.

Cover: “Pelican Sunset” © photograph by C.C. Lockwood, P.O. Box 14876, Baton Rouge, La. 70898.

For additional information on coastal restoration in Louisiana: www.lacoast.gov orwww.savelawetlands.org.

Two thousand copies of this public document were published in this first printing at a total cost of $15,037.28. This documentwas published by the Louisiana Department of Natural Resources, P.O. Box 94396, Baton Rouge, La. 70804-9396 to fulfill therequirements of a coastal restoration plan under the authority of Public Law 101-646. This material was printed in accordancewith the standards for printing by state agencies established pursuant to R.S. 43:31. Printing of this material was purchased inaccordance with the provisions of Title 43 of the Louisiana Revised Statutes.

Coast 2050:Toward a Sustainable

Coastal Louisiana

report of the

Louisiana Coastal Wetlands Conservation and Restoration Task Force

and the

Wetlands Conservation and Restoration Authority

Louisiana Department of Natural ResourcesBaton Rouge, La. 1998

iii

prepared by

COAST 2050 PLANNING MANAGEMENT TEAM of the Louisiana CoastalWetlands Conservation and Restoration Task Force or “Breaux Act Task Force” and theWetlands Conservation and Restoration Authority or “State Wetlands Authority”:

Bill Good, Chairman Louisiana Dept. of Natural Resources

Gerry Bodin U.S. Fish and Wildlife Service

Paul Coreil Louisiana Cooperative ExtensionService

Beverly Ethridge U.S. Environmental Protection Agency

Sherwood Gagliano Coastal Environments, Inc.

Sue Hawes U.S. Army Corps of Engineers

Paul Kemp Louisiana State University

Quin Kinler Natural Resources Conservation Service

Denise Reed University of New Orleans

Ric Ruebsamen National Oceanic and Atmospheric Administration

Glenn Thomas La. Dept. of Wildlife and Fisheries

Lee Wilson Lee Wilson and Associates

COAST 2050 REGIONAL TEAM LEADERS: Darryl Clark, Stehle Harris, SueHawes, Jane Ledwin, Phil Pittman, and Faye Talbot.

OTHER CONTRIBUTORS: Phil Bowman, Louis Britsch, Cheryl Brodnax, CullenCurole, Mark Davis, Greg DuCote, Ken Duffy, Jay Gamble, Steve Gammill, CatherineGrouchy, Bren Haase, Walter Keithly, Mike Liffman, Dianne Lindstedt, Steve Mathies,Gerald Morrissey, Jeanene Peckham, Bryan Piazza, Jon Porthouse, Ken Roberts, RobinRoberts, Gregg Snedden, Joe Suhayda, Cynthia Taylor and Katherine Vaughan.

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ACKNOWLEDGMENTS We would also like to thank those listed below, who, inaddition to those whose names are inscribed on preceding pages, helped to make thisdocument possible in the 18 months available to complete it: Bob Ancelet, JimAnderson, Steve Anderson, Chris Andry, Dan Arceneaux, Neil Armingeon, Donald Ayo,John Barras, Marty Beasely, Ted Beaullieu, Harold Becnel, Sr., Michael Bertrand,Thomas Bigford, Dean Blanchard, Allen Bolotte, Brett Boston, Marty Bourgeois, EdBritton, Charles Broussard, John Burden, Martin Cancienne, Paul Cancienne, DudleyCarver, Jody Chenier, Paul Clifton, Sidney Coffee, Sandy Corkern, Woody Crews,Windell Curole, David Cvitanovich, Doug Daigle, Phyllis Darensbourg, Rhonda Davis,Richard DeMay, Bart DeVillier, Carlton Dufrechou, “Judge” Edwards, Karen Eldridge,Michelle Enright, Tanya Falcon, Gaye Farris, Marty Floyd, Brian Fortson, Stan Foster,Roy Francis, Karen Gautreaux, Clyde Giordano, Rodney Guilbeaux, Vince Guillory,Warren Harang, Robert Hastings, Robert Helm, Vern Herr, Tom Herrington, Tom Hess,Mark Hester, Tina Horn, Jerald Horst, Robin Hote, Michael Hunnicutt, Dale Hymel, TomHymel, Jimmy Johnson, Pete Jones, Robert Jones, Pete Juneau, John Jurgensen, NoelKinler, Tim Landreneau, Lindsey Landry, Brian LeBlanc, Kaye LeBlanc, Mike LeBlanc,Bruce Lehto, Donald Lirette, Oneil Malbrough, Earl Matherne, Larry McNease, VincentMelvin, Clay Midkiff, Cathy Mitias, Dave Moreland, Lindsay Nachishima, Mike Olinde,Ronny Paille, Britt Paul, Randy Pausina, Annell Peek, Guthrie Perry, Loulan Pitre,Samuel Pizzolato, Hollis Poche, Tom Podany, Ed Preau, Terrell Rabalais, Terry Rabot,Kay Radlauer, David Richard, Kevin Roy, Dugan Sabins, Donald Sagrera, SherrillSagrera, Mr. & Mrs. Oliver Salinovich, “Pete” Savoie, Kevin Savoie, Mark Schexnayder,Lynn Schonberg, Robert Schroeder, Deborah Schultz, Gary Shaffer, Tammy Shaw, MarkShirley, Butch Stegall, Charles Stemmans, “Bob” Stewart, Kerry St. Pé, Pam Sturrock,Doug Svendson, Jr., John Taliancich, Ed Theriot, Paul Thibodeaux, Norm Thomas, BethVairin, Bill Vermilion, “Chuck” Villarrubia, Carol Vinning, Jenneke Visser, Ann Walden,Mike Walden, Becky Weber, Marnie Winter, John Woodard, Paul Yakupzack, LindaZaunbrecher, Wayne Zaunbrecher, Jerome Zeringue, and John Zimmer.

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CONTENTS

CHAPTER 1: COAST 2050: THE NEED FOR ACTION . . . . . . . . . . . . 1The Problem: System Collapse in Coastal Louisiana. . . . . . . . . . . . . . . . . . . . . . . . . . . 1Coast 2050: A NEW Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2The Coast 2050 Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

CHAPTER 2: COAST 2050: THE PLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Before Coast 2050 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7The Mission of Coast 2050 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Coast 2050 Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8The Coast 2050 Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10The Role of the Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

CHAPTER 3: COASTAL LOUISIANA TODAY . . . . . . . . . . . . . . . . . . . 19Deltaic Plain Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

The Deltaic Plain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19The Delta Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19The Mudstream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Chenier Plain Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Resulting Landscape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Uplands, Ridgelands, and Fastlands. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Estuarine Basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Barrier Islands and Gulf Shore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

CHAPTER 4: DETERIORATION OF THE LANDSCAPE . . . . . . . . . 31Rates and Patterns of Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Factors Controlling Marsh Sustainability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Sea Level Rise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Subsidence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Aggradation vs. Relative Sea Level Rise . . . . . . . . . . . . . . . . . . . . . . . . 38Survival or Submergence? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Other Major Causes of Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Altered Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Storms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Interior Marsh Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Edge Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Herbivory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Dredge and Fill Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Consequences of Land Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41The Human Landscape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Collapse of the Natural System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

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CHAPTER 5: COASTAL LOUISIANA IN 2050 . . . . . . . . . . . . . . 47Historic Coastal Land Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Projected Land Loss Rates and Locations . . . . . . . . . . . . . . . . . . . . . . . 48Projected Habitat Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

CHAPTER 6: CONSEQUENCES OF LANDSCAPEDETERIORATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Economic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Coastal Communities and Demographics . . . . . . . . . . . . . . . . . . 52Physical Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53Storm Surge Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Consumptive Uses of Wetlands. . . . . . . . . . . . . . . . . . . . . . . . . . 56Nonconsumptive Uses of Wetlands . . . . . . . . . . . . . . . . . . . . . . 57

Major Case Studies and Smaller Vignettes . . . . . . . . . . . . . . . . . . . . . . . 57Community at Risk: South Lafourche Corridor . . . . . . . . . . . . . . 59Community at Risk: New Orleans . . . . . . . . . . . . . . . . . . . . . . . . 63Community at Risk: Yscloskey (St. Bernard Parish) . . . . . . . . . . 64Community at Risk: Cocodrie (Terrebonne Parish) . . . . . . . . . . . 65Community at Risk.: Holly Beach /Constance Beach (Cameron Parish) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Summary of Coastal Communities at Risk . . . . . . . . . . . . . . . . . 67

Fisheries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Historic Trends in Fisheries Production. . . . . . . . . . . . . . . . . . . . 68Projected Trends in Fisheries Production . . . . . . . . . . . . . . . . . . 71Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Wildlife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73Region 1 Wildlife Trends and Projections . . . . . . . . . . . . . . . . . . 74Region 2 Wildlife Trends and Projections . . . . . . . . . . . . . . . . . . 75Region 3 Wildlife Trends and Projections . . . . . . . . . . . . . . . . . . 76Region 4 Wildlife Trends and Projections . . . . . . . . . . . . . . . . . . 76

CHAPTER 7: ECOSYSTEM MANAGEMENT STRATEGIES . 79Strategic Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Coastwide Common Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81Region 1 Strategic Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Habitat Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Regional Ecosystem Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 86Sequencing of Regional Strategies . . . . . . . . . . . . . . . . . . . . . . . 89Local and Common Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 90

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Region 2 Strategic Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92Habitat Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92Regional Ecosystem Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 95Sequencing of Regional Strategies . . . . . . . . . . . . . . . . . . . . . . . 99Local and Common Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Region 3 Strategic Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Habitat Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Regional Ecosystem Strategies . . . . . . . . . . . . . . . . . . . . . . . . . 103Sequencing of Regional Strategies . . . . . . . . . . . . . . . . . . . . . . 109Local and Common Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Region 4 Strategic Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Habitat Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Regional Ecosystem Strategies . . . . . . . . . . . . . . . . . . . . . . . . . 116Sequencing of Regional Strategies . . . . . . . . . . . . . . . . . . . . . . 119Local and Common Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Costs and Benefits of Regional Ecosystem Strategies . . . . . . . . . . . . . . 122Region 1 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122Region 2 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123Region 3 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124Region 4 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Benefits of Regional Strategies to Communities at Risk . . . . . . . . . . . . 125South Lafourche Corridor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125New Orleans Metropolitan Area . . . . . . . . . . . . . . . . . . . . . . . . 125Yscloskey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126Cocodrie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126Holly Beach/Constance Beach. . . . . . . . . . . . . . . . . . . . . . . . . . 126

CHAPTER 8: INSTITUTIONAL ISSUES . . . . . . . . . . . . . . . . . . . 127Breaux Act Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Breaux Act Consistency Requirements . . . . . . . . . . . . . . . . . . . 127Breaux Act Restoration Plan/Coastal Zone Provision . . . . . . . . 128Breaux Act Conservation Plan Implementation Requirements . . 128

Beneficial Use of Dredged Material . . . . . . . . . . . . . . . . . . . . . . . . . . . 129Programmatic Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Coastwide Programmatic Recommendations . . . . . . . . . . . . . . . 131Regional and Mapping Unit Programmatic Recommendations . 133

Compensation Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

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CHAPTER 9: SCIENCE AND TECHNOLOGY . . . . . . . . . . . . 139Research Needs and Improved Understanding . . . . . . . . . . . . . . . . . . 139Improved Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Restoration Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140Predictive Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Information Needs and Database Development. . . . . . . . . . . . . . . . . . 141Integration of Science and Technology–Examples . . . . . . . . . . . . . . . 142The Coast 2050 Science and Technology Challenge . . . . . . . . . . . . . . 142

CHAPTER 10: REALIZING THE GOAL: PRINCIPLES FORIMPLEMENTING THE COAST 2050 PLAN . . . . . . . . . . . . . . . 143

Measures of Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Short Term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Long Term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Scale of Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144Ingredients for Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Commitment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145Knowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Urgency of the Coast 2050 Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

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FIGURES AND TABLES

Figures1-1 Wetlands projected to be lost in the Deltaic Plain between 1993 and 2050 . . . . . 31-2 Wetlands projected to be lost in the Chenier Plain between 1993 and 2050 . . . . . 4

2-1 Coast 2050 organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92-2 Regions used in Coast 2050 plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102-3 Coast 2050 development process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3-1 Map of major coastal Louisiana land forms. . . . . . . . . . . . . . . . . . . . . . . . . . . . 203-2 The Deltaic Plain landmass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213-3 Land building in the vicinity of active distributary outlets.. . . . . . . . . . . . . . . . . 213-4 Barrier island cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233-5a Mudstream offshore.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263-5b Mudstream onshore. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263-6 Coastal Louisiana vegetation zones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4-1 Loss rates of the entire Louisiana coastal area and Deltaic and Chenier Plains. . 314-2 Distribution of land loss in the Louisiana coastal area.. . . . . . . . . . . . . . . . . . . . 324-3 Projected best estimate of worldwide rise in sea level.. . . . . . . . . . . . . . . . . . . . 334-4 Major fault trends and future changes in land elevation of south Louisiana.. . . . 354-5 Subsidence rates in coastal Louisiana by mapping unit.. . . . . . . . . . . . . . . . . . . 374-6 Natural and modified conditions along the Mississippi River corridor. . . . . . . . 434-7 Estimates of Louisiana barrier island area.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6-1 Communities discussed in case studies and vignettes. . . . . . . . . . . . . . . . . . . . . 58

7-1 Coast 2050 habitat objectives for Region 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . 847-2 Coast 2050 Region 1 regional ecosystem strategies. . . . . . . . . . . . . . . . . . . . . . 857-3 Region 1 mapping units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 917-4 Coast 2050 habitat objectives for Region 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . 937-5 Coast 2050 Region 2 regional ecosystem strategies. . . . . . . . . . . . . . . . . . . . . . 947-6 Region 2 mapping units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1027-7 Coast 2050 habitat objectives for Region 3. . . . . . . . . . . . . . . . . . . . . . . . . . . 1047-8 Coast 2050 Region 3 regional ecosystem strategies. . . . . . . . . . . . . . . . . . . . . 1057-9 Region 3 mapping units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1127-10 Coast 2050 habitat objectives for Region 4. . . . . . . . . . . . . . . . . . . . . . . . . . . 1147-11 Coast 2050 Region 4 regional ecosystem strategies. . . . . . . . . . . . . . . . . . . . . 1157-12 Region 4 mapping units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

x

Tables2-1 Milestones concerning coastal restoration in Louisiana. . . . . . . . . . . . . . . . . . . 122-2 Coast 2050 public meetings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3-1 Swamp and marsh salinity ranges and major plant species. . . . . . . . . . . . . . . . . 30

4-1 Subsidence of coastal cities and communities. . . . . . . . . . . . . . . . . . . . . . . . . . 45

5-1 Wetland loss projections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495-2 Existing and projected habitat types in each Coast 2050 region. . . . . . . . . . . . . 50

6-1 Representative fish and invertebrate guilds of coastal Louisiana.. . . . . . . . . . . . 78

1

CHAPTER 1

COAST 2050: THE NEED FOR ACTION

The Problem: SystemCollapse in Coastal

Louisiana

The rate of coastal land loss in Louisianahas reached catastrophic proportions.Within the last 50 years, land loss rateshave exceeded 40 square miles per year,and in the 1990’s the rate has beenestimated to be between 25 and 35square miles each year. This lossrepresents 80% of the coastal wetlandloss in the entire continental UnitedStates.

The reasons for wetland loss arecomplex and vary across the state. Sincethe scale of the problem was recognizedand quantified in the 1970’s, much hasbeen learned about the factors that causemarshes to change to open water andthat result in barrier island fragmentationand submergence. The effects of naturalprocesses like subsidence and stormshave combined with human actions atlarge and small scales to produce asystem on the verge of collapse.

System collapse threatens the continuedproductivity of Louisiana’s bountifulcoastal ecosystems, the economicviability of its industries, and the safetyof its residents. If recent loss ratescontinue into the future, even taking intoaccount current restoration efforts, then

by 2050 coastal Louisiana will lose morethan 630,000 additional acres of coastalmarshes, swamps, and islands. The losscould be greater, especially if worst-casescenario projections of sea-level rise arerealized, but in some places there isnothing left to lose.

Along with the loss of acreage goes theloss of the various functions and valuesassociated with the wetlands:commercial harvests of fisheries,furbearers and alligators; recreationalfishing and hunting, and ecotourism;habitats for threatened and endangeredspecies; water quality improvement;navigation corridors and port facilities;flood control, including bufferinghurricane storm surges; and theintangible value of land settled centuriesago and passed down throughgenerations. The public use value of thisloss is estimated to be in excess of $37billion by 2050, but the losses associatedwith cultures and heritage areimmeasurable.

Coastal planning efforts in Louisianabegan in earnest in the mid-1970’s. Since then, many plans and studies havebeen developed by technical experts,citizens’ groups, and State and Federalagencies.

Primary efforts to prevent catastrophicland loss have been implemented under

2

the Federal Coastal Wetlands Planning,Protection and Restoration Act(hereafter, “Breaux Act”) in partnershipwith Louisiana’s efforts through Act 6(LA. R.S. 49:213 et seq.). Between 1990and 1997, almost $250 million wasallocated through the Breaux Act towardprojects expected to prevent 13% of thisloss. Two separately funded largerprojects, the Caernarvon and Davis PondFreshwater Diversions, with a combinedconstruction cost of approximately $130million, will divert fresh water from theMississippi River into adjacent coastalbasins for salinity control and will alsoimprove conditions within the coastalmarshes. These projects, combined withBreaux Act efforts, should prevent up to22% of the loss projected to occur by2050 (Figs. 1-1, 1-2). The Breaux Actprojects and the two large diversionsdemonstrate that we have the ability toprevent ecosystem collapse, and showthat larger projects can be very effective.

What is needed now is a program thatassures that all the best projects are builtin the most efficient and timely manner.As noted by the Coalition to RestoreCoastal Louisiana (1998), restorationrequires a single coastal plan with a clear,overarching strategic vision, a processfor ensuring effective public input torestoration planning, and integration ofrestoration projects into the overallcoastal management system.

Coast 2050: A NEWApproach

Coast 2050 is a planning effort inspiredby the severity of the problems facingsouth Louisiana, as well as an increasedlevel of confidence in our ability tounderstand the ecosystem and toimplement effective restoration projects. The plan combines elements of allprevious efforts, along with new

initiatives from private citizens, localgovernments, State and Federal agencypersonnel, and the scientific community.

For the first time, as explicitly called forby the Coalition to Restore CoastalLouisiana in 1997, diverse groups havecome together to develop one sharedvision for the coast expressed in thisoverarching goal: to sustain a coastalecosystem that supports and protectsthe environment, economy and cultureof southern Louisiana, and thatcontributes greatly to the economy andwell-being of the nation.

The first step in achieving this goal is toproduce a technically sound plan basedupon managing ecosystems with threeclear strategic objectives:

C To sustain a coastal ecosystemwith the essential functions andvalues of the natural ecosystem,

C To restore the ecosystem to thehighest practicable acreage ofproductive and diverse wetlands,and

C To accomplish this restorationthrough an integrated programthat has multiple use benefits;benefits not solely for wetlands,but for all the communities andresources of the coast.

Important new information has beendeveloped in this innovative approach toplanning. Among other contributions,the Coast 2050 Plan provides newquantitative techniques for projectingland loss patterns into the future, the firstcoastwide assessment of subsidencerates and patterns, and the first

Figure 1-1. Wetlands projected to be lost in the Deltaic Plain (shown in black) between 1993 and 2050 (adapted from LSUNatural Systems Engineering Laboratory, 1998).

LakeSalvador

LakeMaurepas

Lake Pontchartrain

LakeBorgne

BaratariaBay

TimbalierBayTerrebonne

Bay

BretonSound

NewOrleans

Houma3

VermilionBay West Cote

Blanche Bay

East CoteBlanche Bay

AtchafalayaBay

White Lake

Grand Lake

Calcasieu Lake

LakeCharles

Figure 1-2. Wetlands projected to be lost in the Chenier Plain (shown in black) between 1993 and 2050 (adapted from LSUNatural Systems Engineering Laboratory, 1998).

Sabine Lake

4

5

comprehensive consideration of changesin fish and wildlife populations.

Also new is the extent to which theplanning process has involved theaffected public at the local level. Indeed,many of the ecosystem restorationstrategies included in this plan are notnew, but recently they have received farwider understanding and endorsement.The participation of local governmentsand private citizens in plan developmenthas made an essential contribution to theplan.

The level of citizen support for this newapproach to restoration planning incoastal Louisiana is demonstrated byone astonishing fact: councils and policejuries of all 20 coastal parishes havepassed resolutions in support of theCoast 2050 ecosystem strategies.

The Coast 2050 Plan

The information in this document hasbeen organized to include the essentialdetails supporting the need for action incoastal Louisiana and the specificstrategies to accomplish success. Eachchapter stands alone, with anorganization as follows:

• The 18-month process used to buildthe plan is described in Chapter 2,

• Chapters 3-6 detail the landscape ofcoastal Louisiana and the problems itfaces, the implications of thesechanges for fish and wildlifepopulations, and the severeeconomic and human consequencesof continuing on the current path,

• Chapter 7 outlines the ecosystemmanagement strategies essential tothe survival of coastal Louisiana and

expected costs and benefitsassociated with implementation ofthe plan,

• Chapters 8 and 9 address broaderinstitutional issues and scientific andtechnological needs, and

• The final chapter outlines how thisplan should lead to actions that willsave the coast.

A separate document contains theappendices that record much of thedetailed work that went into preparationof the plan. These appendices explainthe new methods used to inventoryexisting conditions and to project futureconditions. They also detail the publicinvolvement in the planning process.

Summary

Coast 2050 has been a truly collectiveeffort among Federal, State, and localgovernments. The effort has beenaffirmed by the adoption of the plan bythe Louisiana Coastal WetlandsConservation and Restoration TaskForce and the Wetlands Conservationand Restoration Authority as theirofficial restoration plan, the transmissionof this plan to the U.S. Department ofCommerce by the State of Louisiana toincorporate it into the Louisiana CoastalResources Program Guidelines, andresolutions of support from 20 coastalparish councils and police juries.

The Coast 2050 Plan is based upon thebest available, albeit imperfect,understanding of both the causes of lossand the effectiveness of restorationmeasures. There is a recognized need tocontinue the study of the system, tolearn from those measures that havealready been implemented, and to learn

6

from the successes and failures of othermajor coastal ecosystem restorationprograms. This plan should be the startof coastal restoration in Louisiana at theecosystem scale, and the restorationeffort must grow and adapt throughtime.

Those responsible for restorationdecisions expect and welcome the factthat the plan will be revised in the future

as new knowledge becomes available, asnew opportunities arise, as newrestoration technology develops, andperhaps as new landscape problemsoccur. Addressing the collapse ofLouisiana’s coastal ecosystem, however,must move forward in the face of suchuncertainty or it will be too late for themarshes, the swamps, the industries, andthe people.

7

CHAPTER 2

COAST 2050: THE PLAN

Before Coast 2050

Coastal land loss in Louisiana began toexceed levels normally associated withthe delta cycle and natural coastalecosystem change during the 1950’s(Britsch and Dunbar 1993). Themagnitude of the changes in thelandscape and their pervasive naturebecame clear during the 1970’s when thefirst of several mapping studies(Gagliano and van Beek 1970) quantifiedthe scale of the problem. Therecognition of the problem led togrowing public concern that coastal landloss be addressed. Governmentalresponse was in the form of legislationand planning programs which havechanged in perspective in the last 30years (Table 2-1). While all themilestones in Table 2-1 have contributedto restoration, those that provided theprimary legal impetus for action are Act361 of 1978, Act 41 of 1981, Act 6 of1989, and the Breaux Act of 1990.

The Breaux Act called for thedevelopment of a comprehensiveLouisiana Coastal WetlandsRestoration Plan (Public Law 101-646§303.b). The first such plan wascompleted in 1993 and has been in usesince that time. In addition, theGovernor’s Office of Coastal ActivitiesScience Advisory Panel prepared a planfor the coast in 1994 for the Wetlands

Conservation and Restoration Authority(State Wetlands Authority), constitutedunder Act 6 (R.S. 49:213.1 et seq.). Atabout the same time, other plans weredeveloped as the need for action becamewidely apparent (Table 2-1).

The Coast 2050 plan has been developedunder the legislative mandates describedabove and is a result of recognition byFederal, State, and local agencies that asingle plan is needed. Such a plan mustincorporate a clear vision for the coast,build on previous work, integrate coastalmanagement and coastal restorationapproaches, and adopt a multiple-useapproach to restoration planning. TheCoast 2050 Plan will serve as the jointcoastal restoration plan of the BreauxAct Task Force and the State WetlandsAuthority.

The Mission of Coast 2050

The Coast 2050 plan was developedbased on the following missionstatement:

“In partnership with the public,develop by December 22, 1998, atechnically sound strategic plan tosustain coastal resources andprovide an integrated multiple useapproach to ecosystemmanagement.”

8

The essential components of this missionwere accomplished by adhering to thethree principles outlined below.

C The partnership with the public wasfacilitated by the direct involvementof parish government Coastal ZoneManagement representatives,briefings to local elected officials,and public meetings (Appendix A). The numerous town meetings andRegional Planning Team meetingsheld during the plan formulationstage demonstrate the level of effortto allow public involvement (Table 2-2). Another important aspect ofpublic participation was theinvolvement of theBarataria-Terrebonne NationalEstuary Program and severalnongovernmental organizations suchas the Coalition to Restore CoastalLouisiana, the Lake PontchartrainBasin Foundation, the Acadiana BayAssociation, and the Vermilion RiceGrowers Association.

C To be technically sound, the planmust be based on the current state ofknowledge of our coastal system. Therefore, academic and privatecoastal scientists were involved inevery step of this planning process. They played key roles on thePlanning Management Team and theRegional Planning Teams and addedto the scientific and technicalexpertise of the Federal and Stateagency personnel.

C The multiple use approach requiredthat coastal wetlands were not theonly coastal resource considered

during the course of this planningeffort (Appendices B-F). Information regarding other coastaluses and resources such asinfrastructure, fish and wildliferesources, public safety, andnavigation was also collected andcarefully considered in developingobjectives and strategies.

The Coast 2050 mission will continueinto the future, reflecting the publiccommitment shown by unanimousparish support, ongoing and expandedefforts in research and development, andintegration of the plan into the CoastalZone Management program.

Coast 2050 Structure

The organizational structure of the Coast2050 planning effort (Fig. 2-1) isindicative of the guiding philosophy ofthis effort. The structure reflects aninteractive planning network in whichscientific and technical matters weredeveloped by the Strategic WorkingGroup, while the public acceptability andcoastal resource objectives were theresponsibility of the Coastal ZoneManagement Working Group. Thesetwo groups were jointly constituted bythe Breaux Act Task Force and the StateWetlands Authority. The StrategicWorking Group consisted of the StateWetlands Authority members and theBreaux Act Technical Committeemembers. The Breaux Act agenciesrepresented were the U.S. Army Corpsof Engineers, the U.S. EnvironmentalProtection Agency, the U.S. Departmentof Agriculture’s Natural ResourcesConservation Service, the

9

Figure 2-1. Coast 2050 organization.

Department of the Interior’s U.S. Fishand Wildlife Service, and theDepartment of Commerce’s NationalMarine Fisheries Service. The LouisianaState agencies represented on theStrategic Working Group were the Officeof the Governor, the Department ofNatural Resources, the Division ofAdministration, the Department ofWildlife and Fisheries, the Departmentof Environmental Quality, theDepartment of Transportation andDevelopment, and the State Soil andWater Conservation Commission of theDepartment of Agriculture and Forestry. The Planning Management Team wasappointed by the Strategic WorkingGroup and was responsible for bothcoordinating the planning effort andwriting this planning document.

The Coastal Zone Management WorkingGroup consisted of parish government

representatives and parish Coastal ZoneManagement Advisory Committees. This working group was largelyresponsible for public involvement: thisoutreach to the public via localgovernments proved to be a particularlyeffective facet of the Coast 2050planning process. The ObjectivesDevelopment Team was responsible forcarrying out the policies established bythe Coastal Zone Management WorkingGroup and soliciting use and resourceobjectives from parish governments,Coastal Zone Advisory Committees, andthe Regional Planning Teams.

The coast was divided into four regionsbased on hydrologic basins (Fig. 2-2). For planning purposes, each region wasbroken into mapping units (see Chapter7).

10

Region 1Pontchartrain

Region 2Breton, Barataria &Mississippi River

Region 4Calcasieu/Sabine & Mermentau Region 3

Terrebonne, Atchafalaya & Teche/Vermilion

Coastal Louisianahydrologic basin area

Figure 2-2. Regions used in the Coast 2050 plan.

Four Regional Planning Teams wereestablished in order to develop strategiesand provide input on coastal use andresource objectives. They furnished thisto the Planning Management Team andto the Objectives Development Team. The Regional Planning Teams consistedof State and Federal agency staff,academic representatives, parishgovernments, Louisiana CooperativeExtension Service/LSU Sea Grant staff,and local volunteers.

The Coast 2050 Process

The planning process was built around aparadigm of consensus building tomaximize the strategies that wereconsidered to be both technically soundand publicly acceptable (Fig. 2-3). Theconsensus building was achieved over 18months and involved a series of publicscoping meetings, regional teammeetings and other gatherings to achieveconsensus concerning the best strategiesto implement on the coast (Appendix A).

Four public scoping meetings were held,one per region, during July and Augustof 1997 in order to further develop theprocess and scope of the plan. RegionalPlanning Team meetings were initiatedon a monthly basis in all four regions. From October 1997 until May of 1998,many important issues were reviewedconcerning strategies and objectives,such as past plans, infrastructure, andresource trends (Appendices B-F).

In order to take advantage of previouscoastal restoration planning efforts, eachRegional Planning Team was provided amatrix that listed all previously proposedprojects and strategies by mapping unit(Appendices C-F). This matrix wascompiled from the plans listed in Table2-1. The Regional Planning Teamsreceived and discussed local technicalinput and public concerns; generatedmost of the mapping unit-scale local,common, and programmatic strategies;and developed many other workproducts.

11

EcosystemNeeds

Acceptableto thePublic

CommonGround

StrategicCoastal

Plan

Consensus Building

Figure 2-3. Coast 2050 development process.

The Planning Management Team alsomet monthly to review input receivedfrom regional meetings, to developregional strategies and other plancomponents, and to prepare thisdocument.

In June and July 1998, 11 town meetingswere held across coastal Louisiana togive the public an update on the planningprocess and to solicit their responses tothe proposed strategies and objectives(Table 2-2). By August 1998, a draftstrategic plan was completed by thePlanning Management Team and theRegional Planning Teams. In September1998, a second set of four regionalmeetings was held to discuss this draftplan with the public. At this stage, all thecoastal parishes involved in thedevelopment of the plan expressed theirsupport for the Coast 2050 strategies bypassing resolutions.

Coast 2050 is the first coastal restorationplan for Louisiana to receive the explicitsupport of all 20 coastal parishgovernments.

On October 20, 1998, the State WetlandsAuthority and the Breaux Act TaskForce jointly discussed therecommended strategies and objectivesalong with the public comments receivedduring the final four regional meetings.Both groups unanimously adopted theCoast 2050 strategies and objectives. Themain report of the plan (this document)was distributed for final review by theBreaux Act Task Force and the StateWetlands Authority in December of1998.

The Role of the Plan

The Coast 2050 Plan was developed inpartnership with the public, parishgovernments, and State and Federalagencies. It is based on technicallysound strategies designed to sustaincoastal resources. The plan is an overalltemplate which will provideprogram-neutral guidance for thedevelopment and implementation ofcoastal restoration projects.

The synergy of the strategies andprogram guidance is intended to providecontinued effectiveness to meet thechallenges of coastal land loss at thescale that is now devastating coastalLouisiana. The Coast 2050 Planrepresents our vision for Louisiana’scoast for the year 2050 and provides acomprehensive strategic plan forachieving this vision.

12

Table 2-1. Milestones concerning coastal restoration in Louisiana.Hydrologic and Geologic Studies of Coastal Louisiana is an 18-report series completed between 1970and 1973. Results reported include: (l) first measurements and identification of the coastal land lossproblem; (2) identification of ecosystem components and processes; (3) evaluation of causes of loss anddeterioration; (4) recommendations for size and location of freshwater diversions and subdeltas; and (5)development of multiple use planning approach. The final report, entitled Environmental Atlas andMulti-Use Management Plan for South-Central Louisiana, has become the prototype for restorationplanning in coastal Louisiana.

Act 35 of the 1971 Louisiana Legislature established the Louisiana Advisory Commission on Coastal and Marine Resources to determine the needs and problems of coastal and marine resources. Theypublished three major reports: Louisiana Government and the Coastal Zone— 1972; Wetlands ‘73:Toward Coastal Zone Management in Louisiana; and Louisiana Wetland Prospectus in 1973.

The Federal Coastal Zone Management (CZM) Act of 1972 encouraged coastal states to assume coastal planning, permitting, Federal consistency, and conflict resolution. (Administered by U.S.Department of Commerce.)

Act 361 of 1978 of the Louisiana Legislature or the “State and Local Coastal Resources ManagementAct” (LA. R.S. 49:214.21 et seq.) established Louisiana’s CZM Program, pursuant to the CZM Act of1972, including: CZM boundary, coastal use permitting, local programs, and Federal consistencydeterminations. (Administered by the Louisiana Department of Natural Resources.)

Act 41 of the Second Extraordinary Session of 1981 of the Louisiana Legislature created a one-time $35million fund for conducting applied research and physical projects to address coastal restoration. The Act also resulted in the formation of the Coastal Protection Task Force which recommended five projectsand a study in a report to Governor Treen in 1982, and a Coastal Master Plan that focused on barrierislands and shorelines. (Made obsolete by “Act 6” of 1989.)

Saving Louisiana’s Coastal Wetlands: The Need for a Long-term Plan of Action was published inApril, 1987 (EPA-230-02-87-026). It was a report of the Louisiana Wetland Protection Panel. Itprovided a comprehensive review of causes of wetland loss and projects authorized at the time. It alsoproposed the development of a strategic plan that would serve to outline necessary actions to preservecoastal wetlands.

The Coalition to Restore Coastal Louisiana (CRCL) was incorporated in 1988. It was established toadvocate the restoration and preservation of Louisiana’s coast. It played a major role in the passage ofAct 6 and the Breaux Act. CRCL is made up of local and national environmental groups, civic andreligious organizations, businesses, industry groups, local governments and concerned citizens.

Coastal Louisiana: Here Today and Gone Tomorrow? was published by the CRCL in 1989. Itadvocated a grass-roots initiative intended to result in the near-term implementation of sedimentdiversions and other structural measures such as barrier island restoration, marsh creation with dredgedmaterials, and regulatory actions such as establishment of special management areas, full mitigation of all primary and secondary wetland impacts, and institutional initiatives such as increased funding forcoastal restoration programs.

13

Table 2-1. Milestones concerning coastal restoration in Louisiana (Cont.).

Act 6 of the Second Extraordinary Session of 1989 of the Louisiana Legislature, or the Louisiana Coastal Wetlands Conservation, Restoration, and Management Act (LA. R.S. 49:213 et seq.), created theWetlands Conservation and Restoration Authority which has oversight of the annual Coastal WetlandsConservation and Restoration Plan. The act also created a renewing fund for restoration effortsauthorized in the plan. The first annual coastal plan was completed in April 1990. The first plan to cost-share on Breaux Act projects was completed in March 1992. Each annual plan provides site-specificproject recommendations.

The Lake Pontchartrain Basin Foundation (LPBF) was established in 1989. It is a nonprofit citizen’sorganization, established by the Louisiana Legislature to expedite the clean-up, restoration andpreservation the Pontchartrain Basin. LPBF has led many initiatives to clean up the lake, includingopposition to shell dredging and the development of a LPBF Comprehensive Management Plan.

The Coastal Wetlands Planning, Protection and Restoration Act, Pub. L. No. 101-646 (1990), is alsoknown as the “Breaux Act.” It resulted in an annual $33 million (approx.) for federal restoration project match and $5 million for planning, and has resulted in annual “Priority Project Lists” since 1992. The Breaux Act also provided for the Louisiana Coastal Wetlands Restoration Plan and the LouisianaCoastal Wetlands Conservation Plan. ( Administered by the Louisiana Coastal Wetlands Conservationand Restoration Task Force.)

The Barataria-Terrebonne National Estuary Program was established in 1990. The program completedand submitted its Comprehensive Conservation and Management Plan (CCMP) in 1996. A ProgramOffice has been established to support the Management Conference, which consists of citizens’ groups,landowners, businesses, agencies, etc. The Management Conference is responsible for implementing this plan, which addresses estuarine quality and biological sustainability. The CCMP development is amodel of effective public input for extensive planning.

Act 637 of 1991 of the Louisiana Legislature (LA. R.S. 49:214.32(F)) requires the LouisianaDepartment of Natural Resources to develop rules and regulations for implementation of a Long TermManagement Strategies Plan. This plan consists of a comprehensive protocol for the beneficial use ofdredge materials. The statute requires beneficial use of any materials dredged from or deposited incoastal waters from the maintenance of any channel longer than one mile or where more than 500,000cubic yards of material are moved.

A Long-term Plan for Louisiana’s Coastal Wetlands was completed in 1993 by S. M. Gagliano and J. L.van Beek for the Louisiana Department of Natural Resources. It provides for comprehensive offensiveand defensive strategies to be carried out in two 25-year phases. Key elements include the establishment of a “Hold Fast Line,” reallocation of Mississippi River flow with the establishment ofphased subdeltas, estuarine management and an orderly retreat seaward of “Hold Fast Line,” andsuccession management of freshwater basins landward of the “Hold Fast Line.” Volume Two listspossible sources of funding for plan implementation.

The Louisiana Coastal Wetlands Restoration Plan was completed in 1993 by the Louisiana CoastalWetlands Conservation and Restoration Task Force. It provided a comprehensive approach to restore and prevent the loss of coastal wetlands. Using a basin planning approach, a number of needed projectswere identified and the implementation of major strategies was called for, such as the abandonment of thepresent Mississippi River Delta, multiple diversions into Barataria, reactivation of old distributarychannels, rebuilding barrier island chains, seasonal increases down the Atchafalaya, reversal of negative hydrologic modifications, and controlling tidal flows in large navigation channels.

14

Table 2-1. Milestones concerning coastal restoration in Louisiana (Cont.).

A Long-term, Comprehensive Management Plan for Coastal Louisiana to Ensure SustainableBiological Productivity, Economic Growth, and the Continued Existence of its Unique Culture andHeritage was completed in 1994 by Dr. van Heerden. This plan “attempts to simulate natural deltagrowth processes by creating river diversions and reestablishing former distributaries ... [and] restoration of Louisiana’s barrier islands.”

An Environmental-Economic Blueprint for Restoring the Louisiana Coastal Zone: The State Plan wascompleted in 1994. This is a report of the Governor’s Office of Coastal Activities Science AdvisoryPanel Workshop. It provides a “long range blueprint for restoring Louisiana’s coastal wetlands, whichincludes several key provisions. The most important of these are: (1) diverting Mississippi River waterand sediments into key locations; (2) restoring, protecting, and sustaining barrier islands; and (3)modifying major navigation channels to reduce saltwater intrusion and storm surge entry.”

Scientific Assessment of Coastal Wetland Loss, Restoration and Management in Louisiana waspublished in 1994. It was authored by Dr. Boesch, et al. and funded by the W. Alton Jones Foundation,Inc. Its purpose was to assess the then-current restoration approaches and wetland loss processes, andprovide scientifically based recommendations to improve restoration efforts. It determined that theBreaux Act was off to a good start, but that (1) region-wide strategies need better integration with small-scale ones, (2) better technical and policy review was needed, (3) private land rights should be balanced with greater public interests, and (4) financing for large-scale introduction of alluvial materialsshould be obtained.

The Louisiana Coastal Wetlands Conservation Plan was completed in May 1997 as authorized by theBreaux Act. The Louisiana Department of Natural Resources developed this plan in conjunction with the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, and U.S. Environmental ProtectionAgency in order to achieve no net loss of coastal wetlands due to development activities. Recommendedactions include public education, innovative technology development, and landowner assistance. Also,implementation resulted in a reduction in the required percentage of state matching funds, as provided for in the Breaux Act.

15

Table 2-2. Coast 2050 public meetings.Date(s) Reg. Location Meeting type Purpose Attend.

7/15-16/97

1 USACE Building,New Orleans

Kick-offRegionalMeeting

Obtain Feedback on Processand Issues for Coast 2050

46

7/24-25/97

3 Nicholls State Univ.,Thibodaux



68

7/29-30/97

2 Yenni Bld., Metairie Kick-offRegionalMeeting


60

8/14-15/97

4 Cameron Police JuryBuilding



60

9/18/97 2 USACE Building,New Orleans

RPT Meeting Status and TrendCompilation and Evaluation

25

9/19/97 3 Morgan CityMunicipal Audit.


30



26

9/23/97 4 Cameron Police JuryBuilding, Cameron


26



47



23

10/17/97 3 AbbevilleCooperative Office


23



50



23



20



25



27



31

16

Table 2-2. Coast 2050 public meetings (cont).



9



18



11



17



21



16



26



38



15


RPT Meeting Strategy and ObjectivesMeeting

19

2/10/98 2 Belle Chase RPT Meeting Strategy and ObjectivesMeeting

20



16



15



28



24

2/25/98 1 Slidell RPT Meeting Strategy and ObjectivesMeeting

8

2/25/98 2 Belle Chase RPT Meeting Strategy and ObjectivesMeeting

16

2/26/98 1 Hammond RPT Meeting Strategy and ObjectivesMeeting

25



19

17


3/12/98 3 Nicholls State Univ.,Thibodaux


22

3/13/98 3 Nicholls State Univ.,Thibodaux


22


RPT Meeting Update and DiscussionMeeting

12

3/18/98 3 New Iberia RPT Meeting Update and Discussion 11

3/18/98 3 New Iberia RPT Meeting Atchafalaya Bay Assn. 23

3/19/98 3 New Iberia RPT Meeting Update and Discussion 18



29

3/31/98 4 Rockefeller StateWildlife Refuge


40

4/07/98 3 New Iberia RPT Meeting Final Strategies andObjectives Meeting

16

4/16/98 3 Morgan CityMunicipal Audit.

RPT Meeting Needs List 9

4/20/98 1,2 Convent CourtHouse, Convent

RPT Meeting St. James AdvisoryCommittee Meeting

14


RPT Meeting Vermilion Rice GrowersAssociation

25

5/20-21/98

1, 2,3, 4

USACE Building,New Orleans

SWG/CZMWGJoint Meeting

Review, Amend and ApproveStrategies and Objectives

51

6/03/98 1, 2,3, 4

Burden ResearchCenter, Baton Rouge

Town Meeting Present, Discuss, & AssessResults of Joint Meeting

26

6/04/98 1, 2,3, 4

Yenni Building,Metairie


22



21

6/10/98 3, 4 AbbevilleCooperative Office


93

6/11/98 3 Bayou Vista CivicCenter, Bayou Vista


15

6/15/98 2, 3 Cut Off YouthCenter, Cut Off


30

18


6/16/98 3 Houma MunicipalAuditorium, Houma


38

6/23/98 2 Port Sulphur CivicCenter, Port Sulphur


20

6/24/98 1 SLU UniversityCenter, Hammond


19

6/25/98 1, 2 St. Bernard GovtComplex, Chalmette


42

7/07/98 2 Jean LafitteAuditorium, Lafitte


27

7/21-22/98

1, 2,3, 4

Holiday Inn Central-Holidome, Lafayette

SWG/CZMWGJoint Meeting

Review and Approval ofStrategies and Objectives

34

9/09/98 4 Burton Coliseum,Lake Charles

RegionalMeeting

Present, Discuss, & AssessResults of Joint Meeting

44

9/10/98 3 National WetlandsResearch Center,Lafayette

RegionalMeeting


15


RegionalMeeting


27

9/16/98 1 SLU UniversityCenter, Hammond

RegionalMeeting


20

Total Meetings : 65

Total Attendance: 1,756

19

CHAPTER 3

COASTAL LOUISIANA TODAY

Coastal Louisiana is made up of twowetland-dominated ecosystems, theDeltaic Plain of the Mississippi River,which occupies Regions 1, 2, and mostof 3, and the closely linked ChenierPlain, which lies within Region 4 and thewestern part of Region 3 (Fig. 3-1). Bothare influenced by the Mississippi River,one of the great natural systems of NorthAmerica. The rich renewable resourcevalues related to the coastal wetlands areto a large extent the product of thedynamic nature of these systems. TheDeltaic Plain and Chenier Plainecosystems are shrinking in size anddeteriorating in function because ofnatural changes and human intervention.The Deltaic Plain, in particular, has lostvital subsystem components andfunctions, and other components havebeen impaired to the extent that thesystem is in a condition of collapse.

Deltaic Plain Processes

The Deltaic Plain

Under natural conditions, a vast wetlandarea developed as a result of delta-building processes (Russell et al. 1936;Fisk 1944; Kolb and van Lopik 1965;Frazier 1967; and many others). Thisbuild-up occurred over a 5,000-yearperiod during which sea level conditionswere relatively stable (Fig. 3-2). Duringhistoric times, delta building has

occurred in only a few areas along theLouisiana coast. One is the activeMississippi delta, where a birdfootpattern of land extends out into deepwater of the Gulf of Mexico (Russell etal. 1936). The second is the AtchafalayaDelta where, since about 1950, subdeltashave formed at the mouths of the LowerAtchafalaya River and the Wax LakeOutlet (Shlemon 1975; van Heerden andRoberts 1988; Roberts 1998).

The Delta Cycle

Delta building is cyclic. The delta cyclebegins when an upstream diversiondirects a distributary of an alluvial rivertoward some low-lying area of the coast(Scruton 1960; Coleman and Gagliano1964). When the stream enters an openwater body (coastal lake or bay) and theflow leaves the confines of the channelbanks, there is a loss of velocity andconsequentially a reduction in thestream’s ability to transport sediment(sand, silt, and clay). Sediment isdeposited to form bars and shoals, whichin turn may cause the channel to branch(Russell et al. 1936; Welder 1959;Coleman et al. 1969). In an open basinof deposition (bay or open gulf) thestream splits or bifurcates (Fig. 3-3),sometimes rejoining. In a closed basin,(such as the lakes in the AtchafalayaBasin) the channel branches and rejoins

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to form a braided pattern. The bars andshoals build up through flood overflowof the banks (overbank processes) andgradually emerge as land when the stagefalls. The newly formed land becomescolonized by wetland vegetation. Thevegetation in turn reduces velocities ofoverbank flow and captures sediment toaccelerate aggradation or build up. Inthis fashion a subdelta lobe forms andadvances seaward (progrades). Majordelta lobes are clusters of subdelta lobesemanating from a common major riverdistributary and form over a period of500 to 1,000 years (Frazier 1967).Subdelta lobes form in 50 to 100 years(Coleman and Gagliano 1964). Thus, aninduced subdelta formation is anachievable event within the time frame ofthe Coast 2050 Plan.

Active delta-building areas aredominated by fresh, turbid water. As thelobe increases in size, the spread andaccumulation of vegetation become thedominant processes in the upper part ofthe system. In many instances,continuous unbroken mats of marshgrass form in basin areas betweendistributary channels. The vegetationimpedes flow and chokes channels.Surface streams become rare, anddrainage becomes sluggish and is largelyrestricted to sheet flow. Energy levelsfrom water movement are very low, andwater becomes anaerobic and stained bytannic acid. These conditions areconducive to preservation of organicparticles and accumulation of peatdeposits (Fisk 1958) as well as theformation of floating marshes in theseinterdistributary basins (Russell 1942;O’Neil 1949).

The delta builds up or aggrades througha combination of alluvial processes(overbank flooding, crevasses, lacustrinedelta building), processes of vegetationgrowth (peat accumulation, flotant), andbiochemical processes (reefs and shellbeaches). Continuation of aggradationalprocesses is essential to maintenance ofthe deltaic landmass. An equallyimportant aspect of this land-buildingprocess occurs when a new subdeltalobe builds around the seaward end of anolder lobe, providing protection to theolder landmass from erosive forces ofthe gulf. As long as delta-buildingconditions remain favorable, the shoreadvances seaward and the delta buildscoastal wetlands (regressive phase). Inabout 5,000 years, this process resultedin a landmass that was approximately7,000 square miles (4.5 million acres) ormore in extent by the early 1700’s.

The deterioration phase begins withnatural closure of distributary feederchannels at their heads (Fig. 3-3). Thesupply of fresh water and transportedsediment is cut off and no longer reachesthe seaward edge of the subdelta. Thenewly deposited deltaic sedimentssubside rapidly, and marine processesbecome dominant. Water conditions inthe lower end of the system becomebrackish and saline. Waves andlongshore currents erode the subdeltaland mass (Fig. 3-4). These processeswinnow out the fine sediment (clays,plant materials, and silts) and leave sandsize mineral particles and shells to formbeaches, barrier islands, spits, andshoals. These formations areprogressively reworked by the wavesand currents into barrier headlands and

24

island arcs, that curve around the frontsof deteriorating subdeltas.

Landward of the barrier islands otherdramatic changes occur. Marine tidalinvasion works its way landward into theextensive wetland areas lying betweenthe distributaries. Under naturalconditions, the invasion is slow and isdriven by factors such as subsidence,storms, and animal eat-outs. Thefreshwater marshes and swampsundergo two changes. Soft substrateareas (floating marshes are particularlyvulnerable) give way to ponds, whichslowly enlarge into lakes and bays.Where the substrate is firm, freshwaterplants are replaced by brackish waterspecies. Brackish and saline marshcommunities become established. Thissalinity gradient, from fresh throughsaline marshes, results in a high level ofbiodiversity. Through this process theinterdistributary basins become moreestuarine in character. At the same timethat slow marine invasion andtransformation are occurring in the lower(seaward) parts of the subdelta lobe,freshwater conditions continue toflourish in the upper (landward) parts ofthe lobe. The invasion process has beengreatly accelerated by dredging ofnavigation channels and canals, whichalter the natural hydrology of the system.

The advanced deterioration phase of thedelta cycle is reached when the barrierislands begin to diminish in size andfragment, and the estuarine baysseparating the barrier arc from themainland remnants of the subdelta lobebecome broad and open. Eventually, thebarrier islands become shoals and the

gulf shore moves inland to the heads ofthe estuarine bays. Freshwaterconditions may persist in the landwardremnants of the lobe from localprecipitation, but the system no longerreceives fresh water and sediment inputthrough the original distributary system. The brackish and saline bays andmarshes are extensive components ofthe current system.

Although a major part of the subdeltalandmass reverts to open waterconditions during this phase, geometryand bottom conditions of the shallowwater bodies are a product of the deltabuilding process. The shallow waterareas are a mix of island remnants,shoals, tidal passes and reefs, whichresult in optimum conditions, howeverunstable, for a large assemblage ofestuarine fish and shore birds. Shell-forming mollusks are particularlyimportant during this phase, as they addcoarse-grained sediment (calciumcarbonate) to the deteriorating delta.These form reefs and wash up tocontribute to islands and beaches(Gagliano et al. 1997). While theterminal stage of the delta cycle isproductive, without renewal throughnew delta growth, erosion anddeterioration would become thedominant processes. This would result inloss of the fringing wetlands, which arethe basis for the productivity.

The delta cycle creates diversity, drivesecological succession and is the basicrenewal process operating in the deltasystem (Gagliano and van Beek 1975;Gosselink 1984). Under naturalconditions, at any one time different

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parts of the Deltaic Plain were indifferent stages of the delta cycle. Thisvariety resulted in maximum diversity offish and wildlife habitat andenvironmental conditions.

The Mudstream

Every active subdelta has a “mudstream”(Fig. 3-5a and 3-5b). This mudstreamconsists of the fine grained sediments(silts and clay) that stay in suspensionbeyond the immediate area of the activedistributary outlets and move along thecoast in response to coastal currents(Morgan et al. 1953; van Lopik 1955;Adams et al. 1978; van Heerden 1983;Wells and Roberts 1980; Kemp 1986;Roberts 1998). Twenty-five percent ormore of the transported sedimentescapes deposition in the immediate areaof the distributary outlets and is carriedaway in the mudstream. If the subdeltais building into shallow waters of a bayor the inner continental shelf, these fine-grained sediments may be transportedby longshore currents. If the mudstreamflows along the fronts of barrier islandsor the gulf shore, tidal action may movesome of the turbid waters intointerdistributary areas through tidalpasses and tidal networks, but sedimenttransported by the mudstream is too finegrained to contribute to the sand budgetsof the islands. Some of the mudstreamsediment may eventually form mudflatsalong the open shore of the gulf. If thedistributary outlets discharge into deepwaters (far out on the continental shelf orbeyond the shelf edge as in the case ofthe modern birdfoot delta) depositionresulting from the mudstream may be onthe sea bottom of the shelf or into the

depths of the gulf. In the latter instance,mudstream sediments are largely lost tothe land building and maintenanceprocesses.

Chenier Plain Processes

The Chenier Plain (Region 4 and thewestern part of Region 3) is a complexsystem influenced primarily by fourcoastal plain rivers, the intermittentlongshore mudstream from theMississippi River outlets, and the Gulf ofMexico. The landforms and geologicalhistory have been described by Howe etal. (1935) and Gould and McFarlan(1959) and the ecosystem by Gosselinket al. (1979). Byrnes et al. (1995) studiedhistoric shoreline dynamics and change. The dominant longshore drift along theLouisiana coast is from east to west, andas a result, during intervals when theMississippi is active along the westernside of the Deltaic Plain, the mudstreammoves fine-grained sediment towards theChenier Plain and mudflats form. Theseare colonized by marsh grass and haveadded new wetlands to the coast.Conversely, when the Mississippisubdeltas have been on the east side ofthe Deltaic Plain, the gulf shore along theChenier Plain has been subjected toerosion. The long-term result during thepast 5,000 years has been episodes ofshoreline progradation interrupted byepisodes of retreat, but progradation hasbeen greater than retreat. A new intervalof land building along the eastern part ofthe Chenier Plain is now unfoldingbecause extensive mudflats began toform about 1950 as a result of outgrowthof the Atchafalaya delta lobes. Since

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1950, the shoreline along the eastern endof the Chenier Plain has beenprograding, and although theprogradation is advancing toward thewest, the rest is still eroding.

During the erosion intervals, fine-grainedmaterials were winnowed out leaving lagdeposits of sand and shell which formgulf beaches. The beach deposits wereshaped by waves and coastal currentsinto ridge systems. A high percentage ofthe composition of the ridges is shell,reflecting the paucity of sand-sizedmineral sediment in the mudflat andmarsh sediment, which was eroded back.The geometry of the ridges is morecomplex where they meet the rivermouth estuaries. Here, fans of accretionbeaches and curved spits occur. Ridgesystems became separated from theseashore during intervals ofprogradation. The relict shell beachridges are covered with live oak trees andstand as linear islands in the marsh.These are the cheniers of southwesternLouisiana. Development of the beachridges and cheniers blocked drainage andsaltwater inflows. This blockage in turnresulted in the development of largefreshwater basins on the landward sideof the ridges.

The marshes and ridges are interruptedby Calcasieu and Sabine Lakes, whichwere initially formed as bays in thedrowned river valleys of the Calcasieuand Sabine Rivers during the Holocenerise of sea level. The rivers form smalldeltas at the heads of these lakes. Thelower ends were naturally blocked by barformation, with only a small tidal passoutlet. Through time, two other large

lakes, Grand Lake and White Lake,developed in the eastern part of thiszone. The Mermentau River passesthrough Grand Lake on its way to thesea. Before the bars across the tidalpasses were removed for navigation, thelakes and adjacent marshes were largelyfresh. On the seaward side of the mostprominent chenier trend, however, was azone of brackish to saline marshes.Locally, tidal stream networks havedeveloped in this zone.

Resulting Landscape

Uplands, Ridgelands, and Fastlands

High, firm land is rare in coastalLouisiana. Elevations of the wetlandsare barely above mean gulf level and atbest the soils are soft and poorlyconsolidated. In contrast to thewetlands, geologically older uplandsbordering the Deltaic and Chenier Plainshave higher elevations and firmer soils.Within the Deltaic Plain, finger-likepatterns of narrow alluvial ridges, whichreach out toward the gulf, are also higherand firmer. These natural levees, formedby overbank processes, occur alongactive and abandoned Mississippi Riverdistributaries. In the Chenier Plain, therelict beaches constitute the highest landand are generally parallel to the gulfshore. In addition, there are human-made ridge features throughout thecoastal lowlands, which include railroadand highway embankments, artificiallevees, and dredged material ridges(“spoil banks”) along waterways.

The natural and man-made ridges formthe skeletal framework to which the

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coastal wetlands are attached. Theyform hydrologic basin divides, and theyare more resistant to erosion than thewetlands. Historically, humansettlement and activity have been on theuplands and have followed the naturallevee and chenier ridges. The alluvialsoils of the higher ridges were fertile andwell suited for agriculture and the ridgesalso provided corridors of access to theresources of the coastal wetlands,estuaries, and the gulf. Deltaic Plaincities such as New Orleans, Thibodaux,Houma, Morgan City, and Empire wereinitially established on the crests ofnatural levees. Chenier Plaincommunities located on old beach ridgesinclude Cameron and Grand Chenier.

Fastlands are areas surrounded byartificial levees, which provide protectionfrom river and storm flooding, andwithin which there is a system ofdrainage canals, ditches, and pumps.These forced drainage areas are usuallylocated between natural levee ridges andadjacent backswamp areas. Within themlie most of the agricultural, urban, andindustrial land of the coastal zone.

The need to use strategic locations closeto the resources and water transportationroutes has resulted in settlement of low-lying ridges outside of the protectivefastland levees. Important unleveedcorridors include Grand Chenier-Cameron, Lower Lafourche, Cocodrie,Lafitte-Barataria, Yscloskey, andDelacroix Island.

The landforms and human settlementpattern are well suited for multiple use.Infrastructure is located on the uplands,within the fastlands, and along unleveed

corridors, while ecosystem managementis appropriate and effective in theestuarine basins (Gagliano and van Beek1975).

Estuarine Basins

The Coast 2050 Plan directs ecosystemmanagement planning toward the vastinterdistributary estuarine basins. Theupper end of the Deltaic Plain basins areoccupied by large freshwater swampsand marshes (Fig. 3-6). Each of thesewetland types is represented by certainplant species (Table 3-1). Thesewetlands are not dependent upon thesea. They can occur far inland from theshore or be completely separated fromthe brackish and saline marshes bynatural ridges or artificial levees. Theymay be subject to rise and fall of the tide,but not ebb and flow. These are lowenergy environments. They changeslowly and have thick sequences oforganic soils or floating grass root mats. They have isolated lakes and backswampdrainage channels, but water movementthrough the basins is largelyunchannelized. The middle and lowerends of the estuary contain lakes andbays fringed by saline and brackishmarshes. These are subject to the ebband flow of the tides, and consequentlythe water is brackish to saline. They arehigher energy areas increasinglydominated by tidal and marine processesin a seaward direction.

Saline grasses require a firm substrate.Such conditions occur in relict naturallevees, over-wash on the bay side ofbarrier islands, rims of bays, banks oftidal streams and firm peat deposits that

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have accumulated initially as freshmarshes. In such instances, salt-tolerantvegetation is able to maintain a firmfooting and can develop a tightlyinterwoven root mat that is resistant toerosion. Like their fresh marshcounterparts, salt marsh islands withfavorable tidal exchange may remainviable for thousands of years, except foredge erosion.

Under natural conditions, there was ahydrologic balance within the basinswhich was a major factor in determiningthe distribution of wetland vegetation.Self-regulating mechanisms controlledoutflow of freshwater runoff and inflowand interchange of tidal waters from thegulf. Change was driven by the deltacycle, but was slow and almostimperceptible.

Barrier Islands and Gulf Shore

Separating the basins from the open gulfare chains of barrier islands. The islandsoccur in four arcs, each of which fringesan abandoned delta lobe (Morgan and

Larimore 1957; Penland and Boyd1981). They initially formed fromreworking of abandoned subdeltas bywaves and currents. Since the sandbudget of each arc is limited to sandwhich can be eroded from the old deltaheadlands, all are sand deficient anddeteriorating (Williams et al. 1992;McBride and Byrnes 1995; Stone et al.1997; Stone and McBride 1998).

Port Fourchon, an important offshorepetroleum industry supply port, islocated on a barrier headland, and GrandIsle, a beach resort and fishing village, islocated on a barrier island. These gulfshore communities of the Deltaic Plainare linked to the mainland by La.Highway 1.

Along the Chenier Plain, segments of thegulf shore are made up of (1) mudflats,(2) shell and sand beaches, and (3) fansof accretion beaches at lake tidal passes.There are also beach resort communitiesin the Chenier Plain, such as HollyBeach and Peveto Beach, that can bereached by La. Highway 82.

Table 3-1. Swamp and marsh salinity ranges and major plant species.

Habitat type Salinityrange (ppt)

Major plant species

Fresh Swamp 0-1 Taxodium distichum, Nyssa aquatica

Fresh Marsh 0-3 Panicum hemitomon, Sagittaria falcata

Intermediate Marsh 2-5 Sagittaria falcata, Spartina patens

Brackish Marsh 4-15 Spartina patens, Scirpus americanus

Saline Marsh 12+ Spartina alterniflora, Distichlis spicata

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CHAPTER 4

DETERIORATION OF THE LANDSCAPE

Rates and Patterns of Loss

The balance of Louisiana’s coastalsystems has been upset by acombination of natural processes andhuman activities. Massive coastalerosion, which began around 1890 andpeaked during the 1950’s and 1960’s,has resulted in loss and deterioration ofwetlands, barrier islands, and ridges (Fig.4-1a,b,c). During a period of little morethan 100 years, more than one millionacres, or about 20% of the coastallowlands (mostly wetlands), haveeroded. Because it took about 5,000years for the coastal lowlands to form, itfollows that 1,000 years of natural landbuilding was eroded in about onecentury. As a result, both the Deltaicand Chenier Plain systems are badlydegraded. The Deltaic Plain has lost andcontinues to lose subsystem componentsand is approaching a condition of systemcollapse.

The distribution of the land loss shedslight on the causes (Fig. 4-2). The lossesare not uniformly distributed, but ratherare concentrated in a few areas. The twoareas of highest loss are (1) within theDeltaic Plain in the lower Terrebonneand Barataria Basins and the MississippiBasin, and (2) in the Chenier Plain in thevicinity of Calcasieu and Sabine Lakes.

Figure 4-1. Loss rates of the entireLouisiana coastal area, Deltaic Plain, andChenier Plain. Land loss rates areexpressed in square miles per year (afterDunbar et al. 1992).

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Year

Sea

Lev

el (i

nche

s)

02468

101214161820

1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

Figure 4-3. Projected best estim ate of worldwide rise in sea level(Wigley and Raper 1992).

There is no single cause for all of thewetland and land loss in coastalLouisiana. The sustainability of thecoastal ecosystems is threatened,however, by the inability of manywetlands to maintain their surfaceelevation in the face of subsidence andsea level rise. A discussion of theseissues and the other major causes of landloss follows.

Factors Controlling MarshSustainability

Sea Level Rise

The combined effect of the worldwiderise of sea level resulting from glacialmelting and subsidence or land sinking results in relative changes between the

elevation of the land and the sea (relativesea level rise).

The average rate of sea level rise iscurrently 0.39 ft/century (0.12 cm/year). Until recently, the sea level rise rate hasbeen low, accounting for only a smallcomponent of the change along theLouisiana coast. Most of the recordedrelative sea level rise has been related tosubsidence. The best estimate of sealevel experts is that the level of theworld’s oceans will increase 8 inches (20cm) over the next 50 years (Fig. 4-3).

Subsidence

Subsidence is the combined effect ofgeological movement along faults andcompaction of poorly consolidatedsediments.

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Compaction

Compaction is related to the type andthickness of Holocene Period (modern)sediment that has accumulated on top ofthe weathered surface of the Pleistoceneformation during the past 5,000 years.This buried top of the Pleistocene is acontinuation of the land surface of theuplands and before burial was exposedby low sea level stands during the last iceage. A prism of modern sedimentarydeposits (sands, silts, clays, peat beds,and shell beds) accumulated above theweathered surface during the rise and therelative still-stand of the sea thatfollowed glacial melting. The poorlyconsolidated clay and peat beds hadhigher water content at the time ofdeposition. They were compacted andlost volume after burial. Thiscompaction process, which stillcontinues, contributes to subsidence.Where these deposits are thick,compaction and subsidence rates arehigher.

Sinking of Fault-bounded Blocks

Hundreds of faults have been mapped inthe coastal area by petroleum geologists(Wallace 1957). The fault pattern iscomplex. Many faults are deep seated,and the most significant occur in trendsand zones (Fisk 1944; Murray 1960; Fig.4-4). These fault trends and zones defineirregularly shaped blocks, which may berising, subsiding, and/or tilting in relationto neighboring blocks (Gagliano and vanBeek 1993).

All blocks within the coastal zone aresubsiding. Upland areas bordering the

coastal zone are generally rising inisostatic adjustment to sediment loadingin coastal basins. Fault trends and zonesseparating rising blocks and sinkingblocks are called hinge lines. Cities onupland rising blocks include Slidell,Mandeville, Ponchatoula, Baton Rouge,Lafayette, Abbeville, and Lake Charles.

The area of most intensive faultingoccurs within a triangle in the DeltaicPlain, which is bounded by the NE-SWtrending Thibodaux fault trend, the NW-SE trending Terre aux Boeufs fault trendand the Gulf of Mexico. Of the manyfault trends cutting across this block, theTheriot-Golden Meadow-Forts faulttrends are the most important andsubdivide the block into a northern andsouthern component (Fig. 4-4).

Subsidence Rates

Data for calculating subsidence comefrom a number of sources. These datainclude: (1) depth of surfaces uponwhich human structures (prehistoricIndian village sites, lighthouses, forts,roads, etc.) were built; (2) radiometricdating of buried peat deposits; (3) tidalgauge records; and (4) sequential landsurveying. The latter technique providesthe best measure of present subsidencerates.

Studies conducted by Shea Penland andothers (Ramsey and Moslow 1987;Penland et al. 1988; Penland et al. 1989;Penland and Ramsey 1990) have led tothe conclusion that the subsidence ratefor the Deltaic Plain is 3.0 to 4.3ft/century (0.9 to 1.3 cm/yr) and for the

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Chenier Plain it is 1.3 to 2.0 ft/century(0.4 to 0.6 cm/yr).

Subsidence rates in some areas of coastalLouisiana have increased significantlyduring modern decades (Van Beek et al.1986; Penland et al. 1988). A small partof this change can be attributed toworldwide increase in sea level. Basedon sequential land surveying measure-ments, the combined subsidence/sealevel rise rate in some of the most severesubsidence areas is more than 3.0 feetper century. Since the present worldwide average rate of sea level rise is only0.394 foot per century, it appears that theland elevation in some areas of coastalLouisiana is being reduced in elevationeight times faster than the sea level riserate. The difference is related to thecombined effects of fault movement andsediment compaction.

The areas of highest subsidence appearto be related to fault movement and arefound in the lower Deltaic Plain withinthe fault-bounded triangle describedabove. Subsidence in the blocksbounded by these faults is high (2.1 – 3.5ft/century). The area of highest rates (> 3.5 ft/century) is found in the lowerdelta below the Forts fault.

Patterns of Subsidence

Figure 4-5 shows patterns of subsidencerates by mapping unit. The rates shownare derived from sequential landsurveying data, which have beenextrapolated to the mapping units on thebasis of fault patterns. The rates shouldbe regarded as “best estimates.” Most ofthe benchmarks where the

measurements have been made arelocated on major natural levee ridges inthe Deltaic Plain. Since none of thebenchmark locations are aggrading, andthe elevations are not referenced to tidegauges, the changes in elevations are truemeasures of subsidence. Littlesubsidence rate information is availablefor the Chenier Plain.

Bordering uplands are stable (Fig. 4-5).Subsidence rates in the Chenier Plain areclassified as low (0-1 ft/century), withone exception. The area aroundCalcasieu Lake is classified as low tointermediate (0 – 2 ft/century). A secondarea of low subsidence is found alongthe north side of the Pontchartrain Basin,including the area north of LakeMaurepas, the Pontchartrain land bridge,and the Biloxi and St. Bernard marshes.

Intermediate subsidence rates occur in abroad band extending from FreshwaterBayou Canal to Chandeleur Sound. Thisincludes Marsh Island and theVermilion-West Cote Blanche, East CoteBlanche, Atchafalaya Bay, Penchant andVerret Basins, the upper Barataria Basin,the Maurepas Basin, and the corridoralong Bayou La Loutre.

Relationship Between Faulting, Subsidence, and Land Loss

There appears to be a strong relationshipbetween faulting, subsidence, and landloss (Penland et al. 1989; Gagliano andVan Beek 1993; Kuecher 1994). Thereare major fault trends and zonesassociated with areas of high land loss(Fig. 4-4). In the Deltaic Plain, the areasof highest subsidence occur within

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the fault-bounded triangle andparticularly south of the Theriot-GoldenMeadow-Forts fault trends. Sixty percentor more of the total land loss for theentire coastal zone, and approximately80% or more of the loss within theDeltaic Plain has occurred within thisfault-bounded area. Three of the fourbarrier island arcs, as well as GoldenMeadow, Leeville, Cocodrie, PortFourchon, Grand Isle, Empire, andVenice, are on the fault-bounded blockswithin this triangle. Relative sea level riserates are expected to be 0.4-0.6 inchesper year in this region by 2050.

Within the Deltaic Plain, between thehinge line and the fault boundedtriangular block, is a zone of relativelylow to moderate sinking rates and landloss rates. The cities of Chalmette, NewOrleans, Houma, and Thibodaux arelocated within this zone.

Aggradation vs. Relative Sea Level Rise

The vulnerability of coastal systems tosea level rise is a combination of theirsensitivity to the change and their abilityto adapt to the change (Raper et al.1996). The elevation of a coastal marshsurface in relation to the tide is critical toits survival and sustainability.

The combined stresses imposed oncoastal marshes by subsidence andeustatic sea level rise require that verticalbuilding of marsh soils must take placeto prevent submergence anddeterioration. The main processescontrolling soil building are inorganicsediment deposition and organic matteraccumulation. The relative importance

of these processes varies across coastalLouisiana with physiographic setting andmarsh type.

Inorganic Sediment Supply andDeposition

The average annual suspended load ofthe Mississippi River presently reachingthe gulf is approximately 78 millioncubic yards. This amount isapproximately half of the sedimentreaching the gulf prior to the 1950’swhen dams were placed on manytributaries of the river and extensivechannel control works wereimplemented (Meade and Parker 1985,Meade et al. 1990). Artificial levees,which now line the lower river almost tothe Gulf of Mexico, however, preventeven this smaller amount of sedimentfrom being dispersed into the adjacentflood plain and wetlands by preventingoverbank flow and crevasse splayformation. Most river sediments arenow funneled to the mouth of the riverwhere they are discharged off thecontinental shelf. There are few directavenues for the input of suspendedsediment from the Mississippi andAtchafalaya Rivers into the coastalwetlands of Louisiana. The isolation ofthe wetlands from riverine sedimentsimpairs their ability to keep pace withrelative sea level rise.

The main source of suspended sedimentto the vast areas of coastal marsh that areisolated from the Mississippi andAtchafalaya Rivers is the reworking ofsediments from the nearshore andcoastal bays during storms (Reed 1989;Cahoon et al. 1995a). Some marshes

39

close to the newly emerging Atchafalayadelta do receive sediments from riverinesources. In these areas vertical accretionrates for non-hurricane conditions arehigh (DeLaune et al. 1992; Childers andDay 1990; Baumann et al. 1984; Cahoonet al. 1995b). In addition, these marshsoils have much higher bulk densitiesthan those of salt marshes in parts of theMississippi Delta removed from riverinesediment inputs (Hatton et al. 1983,DeLaune et al. 1992).

Organic Matter Accumulation

The elevation of some marshes in coastalLouisiana with low sediment input ismaintained by the accumulation oforganic matter within the marsh soil.Organic matter accumulation ismaximized in fresher marshes whichproduce more material and where limitedtidal exchange reduces the export ofplant material.

In areas of low subsidence, such as theChenier Plain, marsh elevation ismaintained through organic matteraccumulation. In areas with higher ratesof relative sea level rise, marsh survivalmay be due to the development of“flotant” or floating marshes. Floatingmarshes are described by Sasser (1994)as “wetlands of emergent vegetationwith a mat of live roots and associateddead and decomposing organic materialand mineral sediments, that movesvertically as ambient water levels rise andfall.” That the mat can move in responseto water level variations suggests thatthese marshes are unlikely to be stressedby gradual increases in relative sea level. O’Neil (1949) suggested that floating

marshes form when natural “attached”organic marshes are subjected tosubsidence or sea level rise and thebuoyant organic mat is subjected toincreasing upward tension. It eventuallybreaks free from its mineral substrateand floats. This adaptation tosubsidence and sea level rise relies uponthe buoyancy of the organic mat— acharacteristic of marshes with minimalmineral sediment deposition. Thus thedevelopment of floating marshes isprobably constrained to areas of lowsalinity, low mineral sediment inputs, afirm skeletal framework (natural levees,cheniers, spoil banks, lake rims, etc.) andlow water energy conditions. Thesefloating marshes are very susceptible todamage by hurricanes.

In brackish and fresh marshes,hydrologic changes which increasesalinity or result in ponding of water onthe marsh surface can cause plantdeterioration. These changes reduce theproduction of organic matter andincrease the sensitivity of the marshes tosubmergence. In addition, large, rapidincreases in salinity may result in plantdeath in the less resilient intermediateand fresh marshes.

Survival or Submergence?

The factors controlling sediment deliveryto coastal marshes depend on the extentof riverine influence and hydrologicreworking of coastal sediments. Inaddition, alterations to marsh hydrologycan affect whether sediments withinchannels and bayous actually reach themarsh surface. Canal spoil banks andlevee impoundments reduce the amount

40

of sediment deposition on the marshsurface (Reed et al. 1997) and mayultimately reduce the ability of affectedmarshes to keep pace with subsidenceand sea level rise. Organic matteraccumulation varies with vegetative type,and the zonation of swamps, fresh,brackish and saline marshes across thecoast reflects gradients in salinity. Variations in sediment supply combinewith gradients in salinity to producecomplex patterns that control whethermarshes can survive relative sea levelrise— whether they are sustainable in thelong-term. At present, different marshtypes are maintained by differentprocesses and the resulting diversity ofhabitat types is an essential characteristicof the productive coastal ecosystem.

Other Major Causes of Losses

Altered Hydrology

Navigation channels and canals dredgedfor oil and gas extraction havedramatically altered the hydrology of thecoastal area. North-south channels andcanals brought salt water into freshmarshes where the salinity and sulfideskilled the vegetation. Saltwater intrusion,caused by channel deepening, endangersthe potable water supply of much of thecoastal region (Fig. 4-6). Canals alsoincreased tidal processes that impactedthe marsh by increasing erosion. East-west canals impeded sheetflow, pondedwater on the marsh, and led to stress andeventual loss. Jetties at the mouth of theMississippi River directed sediment intodeep waters of the gulf.

Storms

Much of the coastal loss has occurredduring storm events, which include notonly hurricanes, but also storms relatedto passages of fronts, which are mostsevere in winter months. Within severaldays, storms can cause major landformalterations to barrier islands and the gulfshore. Alterations may include removaland redistribution of sediment andcreation and alteration of inlets.Hurricane impact is the single mostimportant factor in erosion and alterationof barrier islands. Damage may beequally devastating to muddy shorelines,banks and the marshes. Creation of anumber of large lakes as the result ofrupture and stripping away of root matsin floating marsh have beendocumented. Surge scour may also tearaway rooted marsh vegetation. Saltwater and plant materials pushed andthrown inland by storm surge and tidehave also greatly altered marshvegetation communities. In the ChenierPlain, for example, in 1957 HurricaneAudrey brought saline water into freshmarshes and caused extensive loss.

Interior Marsh Loss

Much land loss and marsh deteriorationalong the Louisiana coast has occurredwhere fresh marshes and swamps havebeen subjected to marine tidal processes,usually the result of subsidence andexacerbated by canal dredging. In suchareas the marshes are affected by severalfactors. First is the invasion of highersalinity water and related sulfideformation, which kills the fresh andintermediate vegetation that makes upthe floating mats. In some instances, thefresh and intermediate grasses are

41

replaced by more salt-tolerant, brackishvegetation, but such vegetation can onlysuccessfully colonize areas of firmsubstrate. Consequently, floatingmarshes and marshes with poorlyconsolidated substrate do not make thetransition to brackish and saline marsh,but instead revert to unvegetated mudflats.

Secondly, if breaches occur in theskeletal framework of natural leveeridges and lake rims which hold the freshand intermediate marshes together, atidal pumping process quickly removesthe fluid and semi-fluid soils and thebarren mud flats are converted to ponds,lakes, and bays.

Edge Erosion

In the past 100 years, the total barrierisland area in Louisiana has declined55% (Fig. 4-7), at a rate of 155 acres peryear (Williams et al. 1992), largely due tostorm overwash and wave erosion. Inmany ways the shorelines of bays andlakes and the banks of canals andstreams are even more vulnerable toerosion than the barrier islands. TheLouisiana coast has approximately 350miles of sandy shoreline along its barrierislands and gulf beaches; however, thereare about 30,000 miles of land-waterinterface along the bays, lakes, canalsand streams. Most of these consist ofmuddy shorelines and banklines, andvirtually all are eroding. In manyinstances, rims of firmer soil aroundlakes and bays, and natural levees alongstreams have eroded away leaving highlyorganic marsh soils directly exposed toopen water wave attack.

Herbivory

Nutria, accidently released in the 1930’s,became unprofitable to trap in the1980’s. The nutria multiplied rapidlyand grazed heavily on marsh plants. This grazing imposed additional stresson marsh plants, frequently resulting inmortality, as well as physicallydisrupting the substrate, therebyaccelerating marsh loss. This destructionof wetland plants has been welldocumented in the Barataria andTerrebonne Basins.

Dredge and Fill Activities

Prior to the regulation of dredge and fillactivities in wetlands, large areas ofswamp and marsh were converted intofastlands for agricultural, residential andindustrial uses. This practice has beenalmost completely halted, but dredgeand fill for petroleum exploration,pipelines, canal developments, andindustrial uses have directly andindirectly contributed to marshdestruction.

Consequences of Land Loss

The consequences of massive landscapechange and ecosystem deterioration arereal for all coastal communities. Someswamps and marshes are presentlysurviving relative sea level rise andprovide the basis for our productivecoastal fishery. Not all parts of thesystem can survive in this way.

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The Human Landscape

Ridges only aggrade or build up whenthey are being formed along the banks ofactive distributaries or as active gulfbeaches. Surface elevations of all relictnatural levee ridges, chenier ridges,artificial ridges, embankments, levees,and fastlands become lower throughtime in response to subsidence. Theprotection levees around fastlandsprevent aggradation; therefore, allfastland areas within the coastal zone aresubsiding (Fig. 4-6). The problem ofreduction of land surface elevation isexacerbated in forced drainage districtswithin fastlands, where drained soilsshrink and compact. Surface elevationswithin some fastland areas in easternNew Orleans are more than 10 feetbelow mean gulf level. Surfaceelevations of the higher lands in selectedcoastal towns and cities are shown inTable 4-1. The projected reductions insurface elevation as a result of thecombined effects of subsidence and sealevel rise by the year 2050 and 2100 arealso shown.

The levees that contain the fastlands areconstructed of earth and cannotwithstand marine erosive forces.Deterioration of coastal marshes meansthese levees are increasingly exposed toopen water. Furthermore, allinfrastructure along the unleveedcorridors is subject to sinking andexposure to waves, tides, and stormsurges.

Collapse of the Natural System

Outside of the fastlands, the coastalecosystem is in a state of collapse. The

combined effect of regional subsidence,alterations to hydrology at all scales,episodic storms, and local factors suchas herbivory and canal bank erosion canlead to conditions across the coastallandscape which cause severe stress towetland plants, and ultimately theirdeath. Any alterations which allowmarsh soils to be excessivelywaterlogged, either by preventingaggradation of the marsh surface or byphysically ponding water within thewetlands, cause soil chemical changeswhich even the most resilient marshplants cannot survive. Once plants die,roots no longer provide structure andintegrity to marsh soils, and land lossresults. The multiplicity of factors thatcontribute to loss and their complexinteractions across the coast produceproblems that are truly vast in scale.

The integrity of the coastal landscape isseverely threatened. The salinitygradients within the estuarine basinssupport the diversity of habitats essentialto the function of these systems. Thesegradients are maintained by the skeletaldistributary ridges and cheniers andbarrier shorelines at the gulf. Becausethe low-lying barrier islands and chenierssuffer overwash and fragmentationduring storms (Fig. 4-7), many of themwill probably be gone by 2050. If thesevital components of the systems areallowed to disappear, the essentialcharacter of the estuarine basins willchange drastically.

Within the basins, the loss of extensivemarsh areas and the progressivedegradation of upper-basin swamps mean that critical subsystemcomponents are becoming massivelydiminished.

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0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

pre 1890 1922-1934 1951-1956 1973-1978 1988

Time Period of Estimate

Are

a (a

cres

)

Figure 4-7. Estimates of Louisiana barrier island area (Wiliams et al. 1992).

While open water habitat is a criticalcomponent of the natural coastal systemin Louisiana, it must be interspersed

with ridges, barriers, marshes, andswamps to provide sustainableproductivity into the future.

45

Table 4-1. Subsidence of coastal cities and communities.

Range of land elevation

(feet)

Subsidence inches/year

(50 Yr)

Subsidenceplus sea level

rise inches/year

(50 Yr)

2050elevation

loss (feet)

2100elevation

loss(feet)

New Orleans* -10.0 to +15.0 0.08 0.30 1.25 2.82

Thibodaux +2.0 to +12.0 0.08 0.31 1.28 2.92

Hopedale +1.0 to +2.5 0.09 0.32 1.35 3.02**

Golden Meadow* -3.0 to +2.0 0.09 0.32 1.35 3.02**

Leeville +1.0 to +2.0 0.12 0.39 1.61** 3.54**

Pointe a laHache* -3.0 to +4.0 0.15 0.44 1.84 4.00**

Grand Isle +1.0 to +2.0 0.18 0.50 2.07** 4.60**

* Areas with forced drainage districts.** Areas where projected loss of elevation approaches or exceeds elevation of highest land.

46

47

CHAPTER 5

COASTAL LOUISIANA IN 2050

Historic Coastal Land Loss

Historic land loss was determined withthe U.S. Army Corps of Engineers(USACE) land loss data base (Dunbar etal. 1992). This data base consists ofeight maps that cover most of theLouisiana coastal area. Areas thatchanged from land to water aredelineated for four time periods: 1932-56, 1956-74, 1974-83, and 1983-90. Theland loss was determined for each of thefour regions for each time period. Then,the Regional Planning Teams determinedthe major causes of loss within eachregion. Data from Penland et al. (1996)were used, in addition to knowledgegained from area residents familiar withthe marsh (see Appendix B formethodology).

From 1932 to 1990, Region 1 lostapproximately 74,800 acres of marsh outof a total of 322,000 acres (Appendix C). Overall, 23% of the 1932 marsh was lost. The construction of the Mississippi RiverGulf Outlet (MRGO) in the early 1960’scaused loss of marsh from both its“footprint” (area of direct impact) andthe saline water it allowed to enter thebasin once the La Loutre Ridge wasbreached. These events led to high lossin the areas surrounding the MRGO andin areas more removed such as thePontchartrain/ Maurepas Land Bridge. Marshes in eastern New Orleans lost

significant amounts of marsh because ofponding of water by levees. Other majorcauses of land loss in the region wereshoreline erosion, subsidence, andaltered hydrology. Much of the recentloss is due to shoreline erosion.

From 1932 to 1990, Region 2 lost nearly360,000 acres of marsh, 35% of themarsh that existed in 1932 (AppendixD). Half of this loss was in brackish andsaline marsh. About one third of the losswas fresh marsh. Altered hydrology andnutria herbivory contributed significantlyto losses in upper Barataria. Marshesfringing large lakes and bays disappeareddue to wind-induced shoreline erosion. In the southern and eastern portions ofBarataria, high subsidence ratescontributed to marsh loss. Excessivewater on the marsh also caused lossalong the lower Bayou Lafourchecorridor. Saltwater brought in bynavigation channels and oil and gasexploration also contributed to losses. Plaquemines Parish marshes west of theriver were lost because of alteredhydrology, saltwater intrusion, andfaulting. Hurricane damage and theextremely high subsidence rates causedmarsh loss in the active Mississippi RiverDelta. Saltwater intrusion and alteredhydrology caused loss of interior marshin the Breton Sound Basin.

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From 1932 to 1990, Region 3 lostapproximately 247,650 acres of marsh,or about 24% of the 1932 marsh(Appendix E). The central and easternportions of the Terrebonne Basinexperienced massive losses of fresh tobrackish marshes. An intermediate tohigh natural subsidence rate and alteredhydrology caused by canals are probablyresponsible for the losses. These twofactors led to excessive flooding in thesewetlands. Shoreline erosion was severealong the fringes of the bays and largelakes. Wetlands in western Terrebonneshowed some loss during this period, butthe rate was much less than in centraland eastern Terrebonne, which is farremoved from the influence of theAtchafalaya River. Even though thesewestern Terrebonne wetlands have a lowloss rate, many of them are stressed byexcessive flooding and ponding of water.

From 1932 to 1990, Region 4 (excludingthe four western mapping units south ofthe Gulf Intracoastal Waterway) lostabout 226,000 acres of the original893,300 acres that existed in 1932(Appendix F). This equates to a loss of25% of the 1932 marsh over the 58-yearperiod. The four mapping units in thewestern portion of the Calcasieu-SabineBasin are not in the USACE NewOrleans District historical land loss database. According to Barras et al. (1994),these four units lost 15,950 acres from1978-90 or 18% of the 1978 marsh. Thesignificant hydrologic alterations causedby major ship channels and the GulfIntracoastal Waterway allow saltwaterintrusion. Locks are often operated in a manner that is less than optimal for the

marsh vegetation. These two factors aremost commonly cited causes of historicwetland loss. Shoreline erosion alongmajor lakes, bays and the Gulf ofMexico, especially in the vicinity ofRockefeller Refuge, is also a significantcause of ongoing loss.

Projected Land Loss Rates and Locations

The 1974-90 marsh loss rate for eachmapping unit was projected into thefuture to estimate the acres of marsh lostby 2050. These numbers must berecognized as a “best estimate.” CoastalLouisiana is estimated to lose nearly514,460 acres of marsh by 2050— 21%of today’s marsh. If the benefits offreshwater diversions (49,000 additionalacres by 2050) and the Breaux Actcoastal restoration projects (nearly66,000 additional acres by 2050) areincluded in the calculations, nearly115,000 acres of that loss will beprevented. Thus, with currentrestoration efforts we should preventabout 22% of the predicted loss. Nevertheless, with the current level ofrestoration we will still lose nearly400,000 acres of marsh. Table 5-1 showsthe acres of marsh lost with and withoutrestoration for various areas of the coast.

The location of the projected loss wasidentified by selectively modifying the1993 LANDSAT image. The result is amap of coastal Louisiana that indicateswhere marsh might be lost by 2050(Figs. 1-1 and 1-2).

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Projected Habitat Conversions

To project the distribution of habitattypes for 2050, the land loss projectionmaps described above weresuperimposed on the 1990 habitat maps. This methodology assumes that thelocation of future habitat zones will notshift. These zones have shifted bothnorth and south in the past, so, that theywill remain as they are is a simplisticassumption.

Table 5-2 shows the acreage of theexisting habitat types in each region and

the projected acreage by habitat type in2050. The habitat type with the greatestprojected marsh loss varies from region to region. In Region 1, 42% of the 1990intermediate marsh is lost by 2050. InRegions 2 and 3, saline marsh shows thegreatest loss with 32% of the salinemarsh in these regions being convertedto open water by 2050. The growingdeltas in Atchafalaya Bay will allowfresh marsh in Region 3 to decrease byonly 2%. In Region 4, brackish marshesshow the greatest losses; 19% of the1990 brackish marshes are projected tobecome open water.

Table 5-1. Wetland loss projections.

Region Basin

Acres ofmarsh in

1990

Acres ofmarsh lost

by 2050without

restoration

Acres ofmarsh

preserved bythe Breaux

Act anddiversions

Net acres ofmarsh lostby 2050 at

currentrestoration

levels

Acres ofswamp in

1990

Acres ofswamp lostby 2050 at

currentrestoration

levels

1 Pontchartrain 253,000 50,330 4,720 45,610 213,570 105,100

2 BretonSound

171,100 44,480 17,900 26,580 0 0

2 MississippiDelta

64,100 24,730 18,340 6,390 0 0

2 Barataria 423,500 134,990 42,420 92,570 146,360 80,090

3 Terrebonne 488,800 145,250 5,170 140,080 152,400 46,700

3 Atchafalaya 48,800 (30,030)* 8,080 (38,110)* 12,600 0

3 Teche/Vermilion

234,300 32,160 3,360 28,800 18,390 0

4 Mermentau 441,000 61,710 2,600 59,110 370 0

4 Calcasieu/Sabine

317,100 50,840 12,440 38,400 170 0

Total 2,441,700 514,460 115,030 399,430 543,860 231,890*Due to delta building, acres will be gained in the Atchafalaya Basin.

50

Table 5-2. Existing and projected habitat types in each Coast 2050 region.Fresh

marsh acresIntermediatemarsh acres

Brackishmarsh acres

Saline marshacres

Total marsh acres

Region 1:

Acreage in 1990 34,700 27,700 110,900 79,700 253,000

Projected acreage in 2050 30,100 16,000 99,900 61,400 207,400

Net acres lost by 2050* 4,600 11,700 11,000 18,300 45,600

Percent 1990 marsh lost 13% 42% 10% 23% 18%

Region 2:

Acreage in 1990 220,100 73,000 214,500 151,100 658,700


Net acres lost by 2050* 25,850 11,100 39,600 49,000 125,550


Region 3:

Acreage in 1990 298,300 92,700 240,700 140,200 771,900


Net acres lost by 2050* 5,970 23,600 55,900 45,300 130,770


Region 4:

Acreage in 1990 354,600 171,700 198,600 33,200 758,100


Net acres lost by 2050* 37,530 20,630 38,400 950 97,510


*includes acres preserved by Breaux Act Priority Lists 1-6 and Caernarvon and Davis Pond Diversions

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CHAPTER 6

CONSEQUENCES OF LANDSCAPEDETERIORATION

Economic Setting

The economic well-being of Louisiana’scoastal communities and thecompetitiveness of the coastal industriesare important not only to the State butalso to national growth and prosperity. To be competitive in the 21st century, theUnited States will continue to depend onLouisiana’s rich coastal resources, andthe nation will be called on to makesubstantial investments to insure thatthese resources are protected and remainproductive over the long term.

Overview

Offshore oil and natural gas production,along with all its related serviceindustries, continues to command theState’s coastal economy. The fisheriesindustry, particularly shrimp, oysters,and menhaden, remains very important. Petrochemical processing andmanufacturing, which dominate theindustrial corridors on either side of theMississippi River from below NewOrleans to Baton Rouge, and theCalcasieu River in the vicinity of LakeCharles, are also of great importance. Industries related to navigation, such asship- and boat-building and repair, aremajor activities along the principalnavigable waterways, and millions of

tons of cargo are shipped annually toand from foreign or inland U.S.locations. Rice, sugar cane, soybeans,and cattle are the most importantagricultural commodities produced in theregion. In fact, until the oil boomchanged the region and State’seconomy, this area was largely anagrarian society where residents farmed,fished, and trapped extensively. Aquaculture, especially the pondaquaculture of crawfish, has become asignificant regional economic activitysince the 1970’s. Extensive tourism andrecreational activities revolve around thearea’s wildlife, fisheries, and wetland-based culture.

Most recently, the region’s economy hasrebounded from a 1980’s downturn inthe oil and gas industry that had resultedin a reduced population, as thousands ofpeople migrated elsewhere to seek work. The main impetus for this recentresurgence has been the discovery of oiland gas in the deepwater fields of thecentral Gulf of Mexico. This discovery,along with deepwater royalty tax reliefand new and improved technology, hasbrought about an increase in offshoreand shore-based activities. The sheervolume of activity that has taken place inthe last three or four years— and theforecast is for this situation tocontinue— has raised serious concerns

52

about the coastal infrastructure’s abilityto handle current and additional growth.

The infrastructure needs, along withfisheries issues and coastal restoration,are the topics of greatest concern tocoastal leaders, according to a 1998study by the Economic DevelopmentAdministration. These leaders havepointed out that recent economic growthhas added pressure to a deterioratinginfrastructure network. Coastal parishesand cities are having to rapidly respondto many deferred maintenance problems,while at the same time having to find themeans for undertaking the additionalpublic works projects urgently needed tocope with new developments.

Coastal leaders also contend that due tothe many challenges facing commercialfisheries and the associated seafoodproduction sector, there is a need toinsure the industry’s sustainability. Traditionally, thousands of Louisianianshave depended on shrimp, menhaden,oysters, crabs, and commercial finfishharvesting and processing. But manychallenges confront this industry and allthe interests involved from Federal andState governments to harvesters,wholesalers, and even consumers willhave to become proactive to insure thesector’s continued importance in thecoastal economy.

Coastal leaders have expressed greatconcern about the continueddeterioration of coastal wetlands. Theirconsensus is that the problem has notonly significant ecological implications,but also major economic ones. Manycoastal communities and economicsectors are at risk, and undue delays in

responding to the problem could resultin grave economic and socialconsequences. For example, habitat lossand major changes in the balance offreshwater and saltwater in theseecosystems can lead to the loss offisheries sensitive to this balance,significantly disrupting Louisiana’svitally important seafood productionsector. Another example is agriculture. Citrus growers in Plaquemines Parish areexperiencing crop losses caused bysaltwater intrusion, and rice growers incentral Acadiana are concerned aboutthe continued supply of fresh water fortheir crops.

Coastal Communities andDemographics

Coastal Louisiana’s residents represent adiversity of nationalities and cultures,including French, Spanish, Portuguese,German, Italian, English, Caribbean,Croatian, African, and American Indian. The largest and oldest immigrant groupto colonize the wetlands is of Frenchdescent. New Orleans was founded byBienville in 1718. Exiled Acadians fromwhat is now Nova Scotia, Canada, beganmoving into the region beginning in the1750’s. According to Donald W. Davis(1994), all immigrants to Louisiana’swetland landscapes developed culturalpractices tied to the annual-use cycle thatis still linked to the region’s naturalresource base. Traditionally, thousandsof coastal residents have been engaged infarming, hunting, trapping, shrimping,crabbing, oystering, and fishing.

Louisiana’s coast is a flat coastallowland characterized mainly bymarshes, swamps, lakes, levees,

53

cheniers, bays and bayous. The areaalso includes several metropolitan andmid-sized communities that serve aspopulation, trade, and service centers. The 1997 population in the 20 coastalparishes was approximately 2 millionresidents, according to U.S. Censusestimates, an increase of 84,000 personssince 1990. Louisiana had over 4.2million residents in 1990 and gainedabout 131,600 persons between thosesame years. In other words, 64% of theState’s population gain during the 7-yearperiod took place within these parishes. In 1997, about 60% of this populationresided in the four most populatedparishes: Orleans, Jefferson, and St. Tammany in the eastern most part of thestudy area, and Calcasieu in the farwestern portion.

Physical Infrastructure

Description of Infrastructure

Physical infrastructure refers to capitalfacilities and land assets— private, State,Federal, parish or municipal— that arenecessary to (1) support developmentand (2) protect public health, safety, andwell-being. It includes, but is not limitedto, water supply and wastewaterdisposal, transportation (ports, roads,bridges, airports, rail, navigation,highways), solid waste disposal,drainage, flood protection, industrialparks, electricity, oil and gas structures,and educational facilities and parks.

Louisiana ranks first in the nation in totalshipping tonnage, handling over 450million tons of cargo each year throughthe public and private installationslocated within the State’s jurisdiction of

six deep-draft ports: New Orleans,Greater Baton Rouge, Lake Charles,South Louisiana, Plaquemines Parish,and St. Bernard. These ports are themainstays of Louisiana’s maritimeshipping industry, and have given theregion both national and internationalprominence. In addition, the privately-owned Louisiana Offshore Oil Portoffloads approximately 10-13% of thecountry’s imported crude petroleum thateventually is moved via pipelines torefineries and consumers throughout thenation. Significant contributions to theState’s economy are also made by thefifteen smaller ports that are situatedwithin the coastal zone, primarily servingthe oil and gas and fishing industries. The Gulf Intracoastal Waterway is acritical shallow-draft transportation linkthat carries an annual average of 70million tons of freight (primarily liquidbulk items such as petroleum andpetroleum products) between theMississippi and Texas state lines. Analternate Gulf Intracoastal Waterwayroute, linking Morgan City and PortAllen, averages 25 million tons of cargoshipped per year.

In addition to the 3,000 miles ofcommercially navigable waterways,coastal Louisiana has railroadtransportation, Interstate, U.S. and statehighways, commercial and generalaviation airports, and an extensivenetwork of oil and gas pipelines. Southern Pacific, Kansas City Southern,Amtrak, Illinois Central, and UnionPacific are the main railroads serving thearea, although several other smallerrailway companies have emerged inrecent years and serve some of the moreremote parts of the region. Interstate

54

Highways 10 and 12, U.S. Highways 90and 190, and La. Highway 82 are themain east-west routes. North-southservice consists of Interstates 49, 55, and59 along with U.S. Highways 51, 61, and165, and La. Highway 1. Several statehighways such as Highways 1, 23, 27,39, and 82 serve as evacuation routesfrom the coastal zone. Some 14,000miles of onshore and 2,000 miles ofoffshore pipelines are located in theregion.

Concerns About Infrastructure

The most frequently identified publicinfrastructure concerns of coastalLouisiana involve roadways, navigationand ports, sanitation and water supplies,drainage and flood control, and coastalerosion prevention structures.

Roads, highways, and bridges, many ofwhich are vital evacuation routes, aredeteriorating and becoming morecongested. Many coastal highways androads are in poor or mediocre condition. Highway 82, for example, in CameronParish is being eroded by gulf waves. Between $20 million and $80 million areneeded to prevent its structural failure inthe next 5 years. Many bridges,particularly those referred to as off-system, are structurally deficient orfunctionally obsolete. In addition, state-run ferries that have served manycommunities in lieu of bridges are beingturned over to local governments, wholack the resources to properly operateand maintain the systems.

Navigation and port interests areconcerned about the continued

development of port facilities and thereplacement of several strategicnavigation structures which havebecome obsolete. The navigation locksin the Gulf Intracoastal Waterwaysystem, including the Inner HarborNavigation Canal in the New Orleansarea, are outdated and need to bereplaced. Ports face severe accessproblems on both the water and landsides, and facilities are inadequate tomeet the growing demands ofinternational commerce and offshoreservices. Additional coastal deteriorationwill only exacerbate the problem.

The environmental infrastructure is alsofacing severe deterioration because ofsubstantial under-funding, particularlyfor solid waste management, watersupplies, and wastewater systems. Notonly is compliance with State andFederal mandates a concern, but if waterquality is not maintained, and in somelocalized instances restored, thissituation will result in negative effects oncertain sectors of the economy. Oysterproduction and harvesting, tourism, andoutdoor recreation are only a few of thesectors that rely on the availability ofclean, safe water supplies.

Local drainage and flood controlinfrastructure are a growing concern forlocal and parish governments. Asprotective marshes continue todisappear, long term maintenance costswill be prohibitive.

In an earlier study for La. Department ofNatural Resources’ Coastal RestorationDivision, the Louisiana Sea GrantCollege Program at Louisiana State

55

University inventoried the majorcomponents of the State’s coastalinfrastructure and estimated its value toexceed $48 billion (Louisiana Sea GrantCollege Program 1998). This figure isconsidered conservative because (1) allpublic infrastructure components werenot included in the inventory— forexample, levees, public utilities, etc. wereexcluded, and (2) the per unit costestimates that were used to arrive at thetotal amount were primarily “rules-ofthumb” figures obtained from experts inthe field, and extrapolated to applythroughout the Coast 2050 study region.

Storm Surge Protection

When a hurricane makes landfall inLouisiana, a large percentage of theinfrastructure damage is caused byflooding associated with the storm surgeand heavy rains. Wind related damage isalso significant, and depending on thestrength of the storm and the location oflandfall, wind damage costs may begreater than the cost of flood damage. Hurricane damages to coastalcommunities can result in increasedcosts of living and doing business inflood prone areas with a concomitantregional economic decline. Historically,this has been followed by gradualemigration from coastal communities(Smith et al. 1998).

It is commonly acknowledged thatbarrier islands and coastal wetlandsreduce the magnitude of hurricane stormsurges and related flooding; however,there are scant data as to the degree ofreduction. The best data availablerelating to this issue come from

continuous water level recorders thatwere in place prior to Hurricane Andrewmaking landfall in St. Mary Parish atPoint Chevreuil on August 26, 1992. Hurricane Andrew was a Category 3storm on the Saffir-Simpson scale. Andrew’s winds produced a positivestorm tide in areas east of landfall and anegative storm tide west of landfall. Thehighest recorded water elevation duringAndrew was 9.3 ft at Cocodrie (Lovelace1994).

Hurricane Andrew gave direct evidencethat the physiography of marshes wherea storm makes landfall affects the degreeto which the storm surge is dampened. The surge amplitude in the Terrebonnemarsh system decreased from 9.3 ftabove sea level in Cocodrie to 3.3 ft(Swenson 1994) in the HoumaNavigation Canal approximately 23miles due north. This equates to areduction in surge amplitude ofapproximately 3.1 inches per linear mileof marsh and open water betweenHouma and Cocodrie. Similarly, themagnitude of the storm’s surge wasreduced from 4.9 ft at Oyster Bayou to0.5 ft at Kent Bayou located 19 miles duenorth. This equates to a reduction insurge amplitude of approximately 2.8inches per linear mile of fairly solidmarsh between these sites.

It is important to bear in mind that theseare data points from only one storm. The role of coastal marshes inameliorating hurricane storm surgesdepends on a variety of factors includingthe physical characteristics of the storm,coastal geomorphic setting and the trackof a storm when it makes landfall.

56

Quantitative computer simulationmodeling of the effect of various barrierisland configurations on hurricane stormsurges (Suhayda 1997) has shown thatchanging coastal inlet geometry at thebarrier shoreline can reduce storm surgesin inland locations such as Cocodrie byover 3 ft. Clearly, the effect of storms onthe human population and infrastructurein the coastal zone can be ameliorated bythe maintenance of extensive coastalmarshes and barrier islands.

Consumptive Uses of Wetlands

Louisiana’s coastal wetlands areessential for numerous species of fishand wildlife, food production, habitat forfish and wildlife reproduction andnursery activities, and overall support ofthe food chain. National MarineFisheries Service statistics for the last 20years indicate that coastal Louisianacontributes about 20% of the nation’stotal commercial fisheries harvest. According to the Louisiana CooperativeExtension Service, in 1995 alone thegross commercial value of coastalfisheries and wildlife productionexceeded $300 million. Value-addedactivities meant another $900 million tothe State’s economy. In 1996, the totaleconomic effect of marine commercialfisheries was $2.2 billion, and $944million for marine recreational fisheries(Southwick Associates 1997). Commercial fisheries resources alsosupport a wide range of related seafoodprocessors and similar operations, andhelp maintain between 50,000 and70,000 jobs statewide in the processing,wholesaling, transporting, retailing, andservices sectors.

Wild fur pelts continue to be harvested,and trappers annually receiveapproximately $1.3 million for theproduct, according to a report to the Furand Alligator Advisory Council(Louisiana Department of Wildlife andFisheries 1997). The same sourcereports that annually the harvest of wildalligators results in skins and meat worthover $9.3 million, and alligator farmingyields approximately $11.5 million peryear.

Coastal Louisiana also provides anexcellent setting for outdoor activity. Use of outdoor recreation resources hasgrown considerably in recent years, andthere are several major initiatives toattract more visitors to the region. Thepreliminary “1996 National Survey ofFishing, Hunting and WildlifeAssociated Recreation” (U.S.Department of the Interior, Fish andWildlife Service 1997) estimated that 1.2million Louisianians enjoy the outdoors,and that between 1989 and 1995, theannualized growth rate in saltwaterrecreational fishing licenses was 6%(Louisiana Department of Wildlife andFisheries 1996). Combination freshwaterand saltwater recreational fishing licensesfor residents and nonresidents for fiscalyear 1997 totaled about 540,000. Charterfishing trips have also been increasingand the latest figures indicate thatapproximately 60,000 nearshore andinland saltwater charter fishing trips weretaken in 1995.

The latest available figures from theLouisiana Department of Wildlife andFisheries indicate that Louisiana had275,000 registered boats in 1994. Over

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49,000 (18%) were registered in the sixCoast 2050 parishes that are contiguousto Lake Pontchartrain: Orleans,Jefferson, St. Tammany, St. John theBaptist, St. Charles, and Tangipahoa.

Louisiana’s coast is at the end of theMississippi and Central flyways, andnearly 70% of the waterfowl migratingalong these routes overwinter at sites incoastal Louisiana. If extensive healthymarsh habitats are not available,waterfowl would return to their nestingareas in a weakened condition, resultingin lower nesting success and decreasedfall flights. Over 90,000 Louisianaresidents and 14,000 non-residentspurchased migratory bird huntinglicenses in 1996. The U.S. Fish andWildlife Service estimates over 860,000migratory bird hunting days for 1996.

Nonconsumptive Uses of Wetlands

The coastal parishes, more than everbefore, are deriving greater economicbenefits from tourism development. Attractions, employment and incomeattributed to this sector have grown, taxrevenues have increased, and virtuallyevery coastal parish is fully organized forand has embarked on this type ofdevelopment. Increased tourism isapparent from the U.S. Travel DataCenter statistics that are compiledannually, by parish, for travel andtourism-related employment,expenditures, and payroll. Between1990 and 1995, the number of personsemployed by this industry grew by over8%; expenditures, when adjusted forinflation, climbed by over 21%; and the

adjusted payroll figures increased by26%. This included over 800,000 visitorsthat engaged in “wildlife watching” orother nonconsumptive uses such asobserving, photographing, and visitingpublic parks and other natural areas.

According to the 1993-98 StatewideComprehensive Outdoor RecreationPlan (Louisiana Department of Culture,Recreation and Tourism 1993), 7 of theState’s 28 state parks and 2 of 12commemorative areas are located in theregion. Some 800,000 visitors made useof these facilities in 1994. Also, theDepartment of Wildlife and Fisheriesand the U.S. Fish and Wildlife Serviceprovide for recreational uses at wildlifemanagement areas and refuges.

Major Case Studies and Smaller Vignettes

Louisiana contains numerous coastalcommunities at the end of natural leveeridges which are surrounded by marshesand estuaries. Examples include:Yscloskey, Venice, Port Fourchon, Islede St. John Charles, Cocodrie, Theriot,and Intracoastal City. People have livedin these small communities for a numberof generations and have traditionallyrelied on the region’s plentiful naturalresource base. Five communities (Fig. 6-1) were chosen to illustrate how futuremarsh loss is expected to affect some ofthe communities, particularly the publicinfrastructure. The discussion of theSouth Lafourche Corridor is detailedbecause Port Fourchon is Louisiana’s

Figure 6-1. Communities discussed in case studies and vignettes (Larger stars indicate communitieshighlighted in case studies and vignettes, smaller stars are other communities mentioned).

Yscloskey

Port FourchonCocodrie Leeville

Golden Meadow

Holly Beach

Lake Pontchartrain

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primary port directly located on the Gulfof Mexico. New Orleans is discussedbecause it represents an area with highpopulation levels. Three othercommunities (Yscloskey, Cocodrie, andHolly Beach/Constance Beach) arediscussed as smaller case studies orvignettes. They were chosen becausethey typify the problems facing many ofLouisiana’s smaller coastal communities. More details on the public infrastructurevalues for each of these communities canbe found in Appendices C-F. CoastalLouisiana communities share a basicconnection to their surroundingenvironments— their cultures andeconomies are part land based and partwater based, and most have becomesimilarly threatened by the conversion ofland to water. The human settlement ofthe region is a history of opportunitiesand constraints. It is very likely that thefuture loss of marsh will tip the balancetoward the constraints in all of thesecommunities.

Community at risk: South Lafourche Corridor

The South Lafourche developmentcorridor is located in the centralLouisiana coast region, in Lafourche andJefferson Parishes (Fig. 6-1). It providesaccess through the coastal lowlands tothe productive estuarine zones and theGulf of Mexico. The corridor is in astrategic position, running along theBayou Lafourche natural levee ridgethrough the Barataria and Terrebonneestuaries. Over the years, it has been oneof the country’s most productive oil andgas regions. The corridor’s strategicposition is enhanced by its role as a

staging area for offshore services,waterborne commerce activities, and as acenter for sport and commercial fishing.

Population

The population of Lafourche Parish, asestimated in 1995, was 87,625 persons. This translates to a parish-widepopulation density of approximately 81persons per square mile. There arehigher population concentrations in theLafourche corridor, where there areapproximately 364 residents per squaremile (U.S. Census 1990, 1998). In effect,85% of the parish’s population lives on18% of the land, an indication of theclustered linear settlement pattern ofnatural levee ridges.

Economy

Renewable and nonrenewable resourceextraction and use characterize theregional economy. The renewableresources are largely the products of thesurrounding estuaries and wetlands:commercial fishing, hunting andtrapping. Most nonrenewable extraction(oil and gas) takes place offshore and inthe estuaries and is highly dependent onthe area’s infrastructure.

The total value of the Lafourcheestuarine dependent industries in 1994was almost half a billion dollars. The1994 value of the renewable resourcesproduced in Lafourche Parish was $70million. Oil and gas extraction had avalue of $388 million. This represents81% of the parish’s resource useeconomy (McKenzie et al. 1995;Industrial Economics 1996).

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Population Settlement Balance

The opportunity/constraint balance inSouth Lafourche has fluctuatedthroughout its settlement history. In the19th century, the opportunities wereprimarily fishing and agriculture. Themain constraint was the proximity to thedangerous forces of the gulf. In the late1800’s, a significant south Lafourchefishing community called Caminadavilleexisted near the gulf on CheniereCaminada, west of Grand Isle. Thechenier had 1,470 inhabitants in 1893when a hurricane destroyed thecommunity. The settlement wasabandoned and most of the survivinginhabitants moved farther inland to thearea that would eventually become thetowns of Leeville and Missville (Rogers1985; McKenzie et al. 1995).

Facing another hurricane in 1909,Leeville and Missville residents took totheir oyster luggers and sought moreprotected land. Though the towns weredestroyed, the majority of residentsrebuilt. Unfortunately, a stronger stormhit the region in 1915, inundatingLeeville and Missville with 20 feet ofwater. Faced again with the destructionof the communities and substantial lossof life, the communities were abandonedand many of the survivors relocated stillfarther north along the bayou to therelative protection of Golden Meadow. The Golden Meadow ridge was the finalstop on their retreat from the gulf(Rogers 1985).

New Opportunities

In the 1930’s, oil was discovered alongthe Lafourche corridor. The once-abandoned Leeville community wasresettled in 1931 and had 98 producingwells by 1937 (Woolfolk 1980). Theeconomic opportunities of oil drewpeople back down the corridor to theplaces from where fisherfolk had onlyrecently retreated. The tremendouseconomic opportunity of oil extractionmade addressing the environmentalconstraints of the South Lafourchecorridor feasible.

Changing Opportunities

Oil and gas activity within the corridor,the surrounding estuaries, and the State’soffshore waters has been in a period ofsubstantial decline. Meanwhile, theFederal offshore industry is presentlyprojecting a 40-year production cycle,with 50% to 100% growth by the year2000 (Cranswick and Regg 1997; Guo etal. 1998). With the industry movingoffshore, the locations of service andsupport industries in Louisiana arebecoming increasingly important. Theland and the gulf are linked by twoimportant complexes in thecorridor— Port Fourchon and theLouisiana Offshore Oil Port.

Port Fourchon is one of Louisiana’s portcomplexes closest to the Gulf of Mexico. Over $750 million of public and privateinvestments have been made in thiscomplex that primarily supports offshoreoil and gas activities in the Gulf ofMexico. Over 100 businesses providesupport for such services. Port

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development has barely kept up with thedemand for waterfront property. Thereis a waiting list of tenants, and the thirdand final phase of the “E-slip”development that has served as thecenterpiece for the port’s growth is beingfast-tracked and is scheduled to becompleted in the next couple of years.

Louisiana Highway 1 is Port Fourchon’sonly land-based access. It is estimatedthat on a monthly basis, 30,000 trucksand over 200,000 passenger vehiclestravel on this highway below Galliano. Traffic flow figures are predicted tocontinue to increase at a rate ofsomewhere between 3% and 6%annually in the next decade with theexpansion of deepwater oil and gasactivities. A major impediment,however, is the Leeville Bridge, whichalready is in a deteriorated condition. Infact, a recent report concludes that 21%of Highway 1 is in poor condition, and98% is in need of some kind ofimprovement (Guo et al. 1998).

Located 21 miles south of PortFourchon, the Louisiana Offshore OilPort is the nation’s only deepwater port,handling between 10% and 13% of thenation’s imported oil supply. Theoffshore facility is connected by a 42-inch pipeline to the Clovelly DomeStorage Terminal, an underground saltcavern in the south Lafourche corridor. The storage terminal is connected by fivepipelines to 30% of the national refiningcapacity. Recently connected to theShell MARS production platform, theLouisiana Offshore Oil Port will handledomestic production as well as foreignimports.

According to preliminary findings of anOuter Continental Shelf (OCS) impactsstudy (Hughes 1998), OCS developmentmay cause substantial growth in the southLafourche corridor. Nearly 60% of thegulf’s future offshore drilling in the next30 years can be served from PortFourchon. An 8-year conservativegrowth projection of almost 5,000 newjobs, with over $500 million in wages, isexpected as a result of OCS expansion. While the recent growth of the industryhas absorbed the existing regional laborpool, future growth may be hamperedbecause the presently taxed infrastructuremay limit growth (Hughes 1998). OCSoperations use Port Fourchon mainlybecause it is the closest port to theiractivities (Falgout 1998). As OCSextraction pushes farther into the gulf,even Louisiana’s central locationbecomes less strategic.

If the South Lafourche corridor continuesto deteriorate, business investments willalso deteriorate (White 1998). It has beenestimated that if the deepwater oil supportindustry is not fully established at PortFourchon by 2000, then oil companieswill expand elsewhere, (Galveston orMobile) and by 2004 will steadily pull outof the port altogether (White 1998). Theeconomic losses to the region would behigh, potentially worse than the oildownturn of the 1980’s. Louisiana’snetwork of 3,819 vendors that receive

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$2.4 billion worth of annual businesscould lose their link to OCS activitieswith an accompanying devastating effecton their businesses. Undoubtably, someportion of the $3 billion annual revenuethat Gulf of Mexico offshore oil and gasoperations generate in Louisiana(Applied Technology Research Corp.1998) would be lost.

Land Loss— The New Constraint

The threat of coastal land loss mayimpede the continued growth and/orsustainability of the south Lafourchecorridor. The social and economicthreats to the Lafourche corridor by 2050from unabated land loss can beevaluated from two distinct perspectives.

1. Theoretical Approach— Impact ofLand Loss on Infrastructure. Withoutpositive human intervention, land losscaused by erosion, subsidence, and otherfactors will continue for the next 50years, much as it has for the last century. It is projected that by 2050, more than 49square miles of marsh will be lost just tothe east of the corridor; over 50% of theadjacent marsh will be open water. Another 33 square miles of marsh just tothe west will disappear, and nearly 70%of these existing marshes will be gone. Highway 1 will be breached in numerousplaces, rendering it impassable. Thetheoretical replacement cost, if the sametype of road could be laid in the sameplace, would be approximately $20million. Approximately 8.5 miles ofsecondary roads would be impacted aswell, at a loss of over $24 million. The119 currently active oil and gas wells,now surrounded by land, could find

themselves in the water, a possible loss of$12.3 million of infrastructure. Approximately 8.3 miles of the ring leveein the vicinity of Golden Meadow wouldbe sporadically exposed to open waterand possibly breached, at a replacementcost of $4.2 million. The value of the lostwetlands, based on an estimated usevalue of $5,000 per acre (IndustrialEconomics 1996), would amount to $260million in losses to recreation andecosystem services to the region.

2. Catastrophic Event Approach—Impact of Storms on People andInfrastructure. It is highly likely that astorm will strike the region and causeextensive damage to the weakenedsystem. This could happen in the verynear term, though each year that land losscontinues unabated and infrastructureremains unprotected, the potential forstorm damage increases. The LouisianaDepartment of Public Safety Services(1985) identified 12 comprehensive stormscenarios and mapped 62 distinct stormsurge patterns. The region isexceptionally vulnerable to storm surgeimpacts. In the event of a category 3, 4,or 5 storm, approximately 35,000 peoplewill need to evacuate from the area southof the Leeville bridge on the onlyevacuation route, Louisiana Highway 1(Curole 1998). In addition to the possibleloss of life and property, acceleratederosion, and cleanup costs typical ofhurricane force storms, a breach in thehighway or damage to the Leeville bridgewould paralyze the largest portion of thecorridor’s economy until repairs could bemade.

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South Lafourche Corridor Conclusion

Human settlement has been drawn to theSouth Lafourche corridor for the past1,000 to 2,000 years because of theestuary, the marshes, the Gulf of Mexicoand the natural levee ridges. Land loss isnot just a constraint to realizing theregion’s resource opportunities; itthreatens the very existence of theopportunities. The marshes andtransportation access to the gulf arethreatened, and the dangers of the gulfhave only become more dangerous tothe corridor. The potential impact ofland loss in the corridor is the eventualabandonment of the corridor as a viablecommunity. Like Caminadaville in 1893,Leeville (and Missville) in 1909 and1915, and other similar settlements alongthe gulf that have faced overbearingconstraints, the choice is either toabandon the corridor or recognize thedangers and defend against them. Reversing the land loss is the first step inthat defense.

Community at risk: New Orleans

All communities in Louisiana south ofI-10 are threatened by coastal erosion,but New Orleans’ potential losses areespecially high. New Orleans lies at thecenter of a nearly 2,600 square milemetropolitan area containing 1.2 millionpeople and five parishes (Fig. 6-1). Taxable real estate and property in theregion are assessed at more than $5billion, and fair market value of theseassets exceeds $40 billion.

The Threat

The Mississippi River flows through thecenter of the metropolitan area. Thenorthern boundary is Lake Pontchartrainand coastal wetlands surround the othermargins. No other major city in thecountry is surrounded by so manyflood-prone habitats. New Orleans isvirtually an island already; as wetland losscontinues, the amount of water aroundthe city will increase. In addition, at least45% of the metropolitan core is at orbelow sea level. In New Orleans,elevations vary from 10 feet below sealevel in developed areas to 15 feet abovesea level along the natural ridges of theMississippi.

Today, New Orleans is protected fromflooding rainwater, river water andseawater by 520 miles of levees andfloodwalls, 270 floodgates, and 92pumping stations connecting thousandsof miles of drainage canals and pipes. The wetland buffer that now partiallyprotects New Orleans from storm surgesis disappearing. By 2050, the city will becloser to and more exposed to the Gulf ofMexico.

Hurricanes pose the worst threats.

C In 1965 the eye of Hurricane Betsy (aCategory 3 storm) passed about 50miles west of New Orleans and thetidal surge into St. Bernard andOrleans Parishes caused $2 billion indamages and 81 deaths.

C In 1985 Hurricane Juan (a Category 1storm) caused higher tides than Betsyin some areas because of its slow

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movement. The West Bank ofJefferson Parish sustained $52million in damage.

The current hurricane protection system,to be completed in 2002, protects the cityfrom a storm surge associated with a fastmoving Category 3 hurricane. But whatif the storm is more intense (HurricaneCamille in 1969 was a Category 5) or thestorm moves slowly, allowing more timefor the storm surge to build? Stormsurge models show that a hurricanecould produce an 18-foot storm surge inLake Pontchartrain, which could betopped with 10 foot waves. None of thecurrent or planned protection measureswould be effective under thosecircumstances.

The Possible Consequences

Unfortunately, storm surge heights willonly increase as subsidence and sea-levelrise continue and more wetlands are lost. A portion of the West Bank of Orleansand Jefferson Parishes, bounded by theMississippi River and Harvey Canal, is a22,500 acre urban area with substandardhurricane protection and 34,362structures valued at more than $3 billion. The projected future for this areacombines the effect of a 100-year returnperiod hurricane on a landscapeexperiencing continued wetland loss. Some structures in this area, which in1991 would flood with a 100-year event,by 2050 would flood with only a 50-yearevent. The cost of a 100-year hurricanefor these structures, their contents, andvehicles in the area could increase by280% in this area of the West Bank by2050. The cost of flood damage from

such a storm in 1991 would theoreticallyhave been $629 million, by 2050 thiscould increase to $1.8 billion.

Community at risk: Yscloskey (St.Bernard Parish)

The small fishing village of Yscloskey liesin St. Bernard Parish about 25 miles eastof New Orleans (Fig. 6-1). The village isat the intersection of Bayous La Loutreand Yscloskey and is entirely surroundedby marshes and estuaries. The areaanalyzed for this vignette includes allstructures along Louisiana Highway 46from its junction with Louisiana Highway300 to the end of Highway 46 at theMississippi River Gulf Outlet. Thesehighways link the fishing communities ofSt. Bernard Parish with the New OrleansMetropolitan Area.

Approximately 325 permanent residentslive in Yscloskey (Metrovision 1998). Inaddition, there are approximately 50commercial establishments in the generalvicinity. Fishing is the most importantaspect of the local economy. A trip to thearea reveals oyster luggers offloadingsacks of oysters at the wholesale houses,and shrimp boats docked beneath mosscovered oaks along the scenic bayous. Recreational fishing is also important, andseveral marinas cater to anglers. Whenthe Mississippi River Gulf Outlet wasbuilt, the residents of Old Shell Beach hadto be relocated and many moved west toYscloskey.

The entire length of Highway 46 fromVerret east lies outside the hurricaneprotection levees. Hurricane Betsyheavily damaged the corridor in 1965, and

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in 1969 Hurricane Camille destroyedmany homes and boats.

The community’s public infrastructureincludes a fire station and a communityhall. The transportation infrastructureincludes 1.75 miles of paved road onHighways 46 and 624, one mile ofasphalt road, and a lift bridge acrossBayou La Loutre, built in 1957. A powersubstation, transmission lines,distribution lines, and transformerssupply electricity. The water supplysystem consists of a water tower withcorresponding supply lines.

Land loss in the vicinity of Yscloskey ismoderate. The marshes to the south arebenefitting from the CaernarvonFreshwater Diversion Project, but willstill lose nearly 10 square miles by 2050. Thirteen percent of the existing marsheswill be open water. To the east andnorth more than 34 square miles ofmarsh will be lost by 2050, causingnearly 16% of today’s marshes to beconverted to open water. This loss ofland will mean that the infrastructure atYscloskey is at even greater risk fromstorms and high waters.

The replacement cost of the bridge overBayou La Loutre is estimated at between$4 million and $5 million, the pavedhighway at $5.25 million, and the asphaltroad at $1 million. The total replacementcost of roads, highways, and bridges inthe Yscloskey area is $10.75 million. Electric lines and transformers wouldcost approximately $98,000 to replace. The power substation has a replacementcost of $1.3 million. The replacement ofnatural gas lines in Yscloskey would cost

between $116,000 and $174,000. Thewater tower is valued at $261,000, and itssupply lines have a replacement cost of$80,000. If the entire communityinfrastructure had to be replaced becauseof a combination of marsh loss and stormdamage, it could cost as much as $13million. Marsh loss will also affectpeople’s livelihoods. As significant areasof marsh are lost, there will be feweroysters, shrimp, spotted seatrout, and reddrum.

Community at risk: Cocodrie(Terrebonne Parish)

Cocodrie is a village located in thesouthern marshes of Terrebonne Parishbetween the Houma Navigation Canaland Bayou Petit Caillou (Fig. 6-1). Thestudy area includes the lower 8.7 miles ofHighway 56 ending at Point Cocodrie. Approximately 600 people live in the area(Metrovision 1998). There are 200residential structures and approximately20 commercial buildings located in thearea. Cocodrie is entirely surrounded bymarsh, and there is no hurricaneprotection for the area.

Cocodrie is an ideal location forrecreational fishing. Recreational anglers,along with commercial fishing guides,operate out of local marinas. Severalcommercial fishing operations are alsopresent. Cocodrie is the home ofLouisiana Universities MarineConsortium (LUMCON), home of theW.J. DeFelice Marine Center. The marinecenter is a 75,000 square foot complex ofresearch, instructional, housing andsupport facilities. It includes 26,000square feet of laboratory, classroom,

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office, and library space. Dormitoryrooms and apartments provide housingfor up to 80 people. The only otherpublic building in Cocodrie is a firestation at the northern extreme of thestudy area. There are 8.7 miles ofpavement on Highway 56, five miles ofgravel road, and a bridge just south ofthe fire station. The water supply systemincludes a water tower, a meteringstation, and supply lines. There are alsonatural gas lines serving the area. Cocodrie’s public infrastructure isestimated to be worth over $53 million.

Land loss in the vicinity of Cocodrie isprojected to be very severe. By 2050over 55% of the marsh north of Cocodriewill be gone. Even more seriously, over65% of the marsh to the east and 35% ofthe marsh to the west and south willhave turned to open water. The barrierislands to the south will be tiny remnantsof what they are today. Even if Cocodriewere to still exist by 2050, it would be anisland community surrounded by water. The sport and commercial fisheries willbe seriously reduced.

Loss of marsh will significantly impactthe public infrastructure. Roads,highways, and bridges will have to bereplaced and raised at an approximatecost of $27 million. The public utilitieswill be at much greater risk than they aretoday from hurricanes or even winterstorms. The replacement cost ofelectrical utility infrastructure isestimated at almost $800,000. The costestimate for replacing the water supplysystem is approximately $1 million. Natural gas lines would have to bereplaced at a cost of nearly $580,000.

The replacement cost of LUMCONwould be approximately $24 million. Thefire station is valued at $150,000. If theentire infrastructure had to be replaceddue to a combination of marsh loss andstorm damage, it could cost up to $53million.

Community at risk: Holly Beach/Constance Beach

(Cameron Parish)

The Holly Beach/Constance Beachcorridor is located in Cameron Parish(Fig. 6-1). It includes the area from theintersection of Louisiana Highways 27and 82 westward for 10 miles alongHighway 82 toward the town ofJohnson’s Bayou. The area containssome of the few sand beaches alongLouisiana’s Gulf of Mexico Coast. Thesmall communities of Holly Beach,Constance Beach, Martin Beach, PevetoBeach, and Little Florida are clusteredalong the highway. Approximately 800permanent residents live in the area. Proximity to Lake Charles and othercommunities in southwest Louisianamake this an ideal spot for a weekendvacation. There are approximately 400residential structures in the area andnearly 100 commercial establishments. Many of the structures are small campsand motels that serve the area’srecreational and tourism interests. Hunting, fishing, birding, and beachrecreational activities are the major touristattractions.

The community infrastructure includes afire station and an ambulance building onHighway 27. There are approximately 10miles of highway and seven miles of

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bituminous road in the area. Highway82 is part of the Creole Nature Trail. Another highway of importance to thebeaches lies outside the study area. Louisiana Highway 27 runs north fromthe gulf through the Sabine NationalWildlife Refuge to high ground nearLake Charles. Highways 27 and 82 arethe only hurricane evacuation routesfrom the beaches and the communitiesalong the coast. There are no hurricaneprotection levees in the area. There is apower substation on Highway 82 and atransmission line runs the length of thehighway. A water tower and 17 miles ofsupply lines bring water to the area.

In this area, coastal erosion has led toshoreline retreat such that La. Highway82 is now at the Gulf of Mexicoshoreline. The highway has beenseverely damaged during several winterand tropical storms and has been movedlandward several times. It is now builton the last natural ridge, or chenier,before the marsh. Between 1991 and1994 the Louisiana Department ofNatural Resources constructed a seriesof 85 breakwaters along 8 miles of thecoastline. The combined cost of thesebreakwaters and other road-protectionmeasures has been over $12 million inthe last 10 years. The breakwatersprovide some protection to the highway,but more work is needed to prevent lossof the highway. It cannot be relocatedfarther inland because of the lack ofsuitable substrate in the marsh plain. Ifthe highway can no longer be maintainedand the chenier is breached, there will beinterior marsh loss.

La. Highway 82 is one of the two roadsout of this area. By 2050, approximately20% of the marshes north of this highwaywill become open water. If these marshesare not protected, the evacuation routewill be more at risk. Shoreline erosion onthe gulf side is already a problem, but asthe interior marshes are lost, the ridge onwhich the road is built may be exposed toattack from the northern side as well(albeit of a lesser magnitude). Ifmeasures are not taken to protect theshoreline and to maintain the interiormarshes, community infrastructure worth$300,000 will be at risk. Moreimportantly, communities will need torelocate because their hurricaneevacuation route, as well as their meansof conducting everyday business, will belost. The replacement cost of the roadswould be $37 million. The utilityinfrastructure replacement cost would be$2.1 million.

Summary of Coastal Communities at Risk

The Fourchon corridor and the threeisolated communities discussed in thevignettes all share a reliance on thewetlands surrounding them. Theydepend heavily on the fish and wildlifethat, in turn, are dependent on thevanishing marshes. They rely onecotourism that is based on the naturalresources of the coast. Their livelihooddepends on the oil and gas resources inthe wetlands or offshore. People live inthese communities to be near thebountiful resources of the coast. NewOrleans sits astride the Mississippi River,surrounded by lakes and wetlands, anddepends on shipping, tourism, and

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manufacturing. Its inhabitants recreatein the wetlands. The severe loss of thewetlands that is projected to occur in thefuture puts all these communities at risk.

In the past, people made decisions thatare destroying the coastal resources: thewetlands, the fisheries and the wildlife. The opportunity now exists to slow theloss of wetlands, which will preserve thenatural system while at the same timehelp these communities to continue toexist. It is a wiser decision to save thewetlands than to move communities orreplace the infrastructure. By preservingthe wetlands, we would help preserve away of life and retain the economicviability of these coastal communities.

Fisheries

Loss of coastal wetlands in Louisianahas severe implications for the long-termsustainability of fisheries resources. Theremarkable level of productivity of theState’s marine systems is tied to both thequantity and quality of estuarinefisheries habitat. Recent high productionhas been linked to the amount of land-water interface, which is highest inmarshes undergoing the early stages ofsubsidence and disintegration. A drasticdownturn in the harvest of the majorityof the most valued species of fish andshellfish is expected as open waterreplaces marsh in most areas. Coastalfisheries resource managers are lookingtoward coastal restoration for protectionof existing wetlands and the creation ofnew marshes to replace some portion ofthose which have been lost.

Historic Trends in Fisheries Production

Methodology

To assess the recent trends and futureprojections of fishery populations withinthe Coast 2050 study area, four broadspecies assemblages were establishedbased on salinity preferences. Theseassemblages were marine, estuarinedependent, estuarine resident, andfreshwater. Within each of the fourassemblages, “guilds” of fisheryorganisms were established. As used inthis document, “guilds” are groupings ofecologically similar species identified by asingle, representative species and,hereafter, the terms “guild” and “species”are used interchangeably. Fishery guildscommon to coastal Louisiana, withineach salinity-preference assemblage are:

C Spanish mackerel guild— marine,

C Red drum, black drum, spottedseatrout, gulf menhaden, southernflounder, white shrimp, brownshrimp, and blue crab guilds—estuarine dependent,

C American oyster guild— estuarineresident, and

C Largemouth bass and channel catfishguilds— freshwater.

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In a broad sense, each of the 12 guilds isuniquely identified by the combinationof the representative species’ habitatpreference, salinity preference, primaryhabitat function, seasonal occurrence inthe estuary, and spawning or migratoryseasons (Table 6-1). Habitat and lifehistory information is based on availablescientific literature specific to thenorthwestern Gulf of Mexico, but it issomewhat generalized to accommodatethe establishment of guilds.

Once the species representing eachfishery guild was identified, populationchanges of each species were assessedand displayed by using a matrix for eachof the four coastal regions (see AppendixB for methodology, Appendices C-F forRegions 1-4, respectively). The matricesdisplay mapping units and guilds and,within the mapping units, provideinformation on the population stability(recent change trends) and populationprojections for each species group. Thediscussion of fishery populationprojections follows this section. Most ofthe recent trend information wasprovided by biologists of the LouisianaDepartment of Wildlife and Fisheries(LDWF). The assessments were basedon LDWF fishery-independent samplingdata and personal observation of areafishery biologists, and generally span aperiod of 10 to 20 years. Staff membersof LDWF believe that, because ofselectivity of sample gear, the trendinformation is most reflective of recentchanges in the subadult portion of eachguild. Historic trend informationrepresented in each coastal region matrixis summarized below.

Region 1 Trends

Within Region 1 (Appendix C), thefreshwater assemblage, represented bylargemouth bass and channel catfishguilds, occurs in the low salinity(generally less than 2 parts per thousand)to freshwater areas of the basin. Ingeneral, freshwater fishery populationshave been steady over the past 10-20years. Similarly, the Spanish mackerelguild, representing the marine fisheryassemblage and found only in highersalinity waters on the perimeter of thebasin, has exhibited stable populationnumbers.

The estuarine dependent speciesassemblage is found throughout LakePontchartrain and in the brackish to salinezones of the Lake Borgne and ChandeleurSound areas. With the exception of thered drum guild, whose populations haveincreased in the eastern units of theregion, recent population levels have beenrelatively steady for all guilds throughoutthe units in which they occur. Theresident species assemblage, representedby the American oyster, has exhibitedsteady to declining populations.

Not included within the matrix is the gulfsturgeon, which is federally listed as athreatened or endangered species. Population levels in coastal Louisiana areunknown; however, recent recordsindicate that this anadromous speciesoccurs in this region.

Region 2 Trends

Region 2 (Appendix D) exhibits mixedpopulation trends among mapping units

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and species guilds. The freshwaterassemblage occurs in the upper and mid-basin zones, the Mississippi River deltaand in the vicinity of freshwaterdiversions. Largemouth bass exhibitedgenerally steady population levels, as didchannel catfish, except in several of themid-basin mapping units wherepopulations increased in response tofreshwater input.

The marine assemblage guild (Spanishmackerel) showed steady populationtrends in the Mississippi River deltaunits. Within the lower estuary andbarrier island units, populations showedpatterns of increase.

Estuarine resident and dependent speciesdo not occur in the uppermost units ofRegion 2. No guild showed a consistentpattern throughout all mapping units. Ingeneral, species within these guilds haveshown decreasing numbers in unitsnearest the Gulf of Mexico, increasinglevels in the vicinity of freshwaterdiversions, and steady populations inother mid-basin and Mississippi Riverdelta mapping units.

Region 3 Trends

Region 3 (Appendix E) includes multipleestuarine basins, extending from theTerrebonne/Timbalier Bay complex tothe Vermilion Bay estuary. Similar toRegion 2, fish and shellfish within thesebasins exhibit mixed historic trendsamong mapping units and species guilds. The two guilds within the freshwaterassemblage show stable populationtrends, except in the central basin area

where populations have generallydecreased.

Where the marine guild representativeoccurs, in the gulf fringe of the basin,populations have tended to increase inRegion 3.

The estuarine resident, American oyster,shows both increasing and decreasingtrends except in the western units wherepopulations are reported to be stable. Upward and downward trends of theoyster appear to be related to recenthabitat and salinity shifts, occurringbetween the barrier islands and theintermediate/brackish marsh zones of theTerrebonne estuary.

Estuarine dependent species also have anerratic pattern of change from steadypopulation levels. An overall pattern ofpopulation decreases is noted for thebarrier islands, Marsh Island, and theTerrebonne, Penchant, and Pelto marshes,while generalized increases are reported inthe area of the Houma NavigationChannel and for the guild represented byred and black drum and blue crab. Fromthe Atchafalaya subdelta west, generallysteady population trends were noted.

Region 4 Trends

Region 4 (Appendix F) contains twoestuarine basins: Mermentau andCalcasieu-Sabine. The two guildsrepresenting the freshwater assemblageexhibit steady population levels in nearlyall units providing suitable fresh to lowsalinity habitat in the basins. Exceptionsoccur in several units in the vicinity of

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Black Lake and Sabine Pool, wherepopulation increases have occurred.

Spanish mackerel from the marineassemblage had limited occurrencewithin these basins. Present in the lowerportions of Calcasieu Lake and near thegulf shoreline of the Rockefeller Refugearea, populations have been steady.Among the species representing theestuarine dependent assemblage, bluecrab populations have been steady. White and brown shrimp have shownsteady to declining patterns, with agreater number of units showingdeclines, especially in the Calcasieu-Sabine basin. Geographically, estuarinedependent species have tended todecline in the Grand Lake, Mud Lake,Southeast Sabine, Brown’s Lake, WestBlack Lake, and Cameron-Creolemapping units, which are areasinfluenced by weirs and other types ofwater control structures. Other units,some of which are also subject to waterlevel control, often reflected steady toincreasing population patterns.

Projected Trends in Fisheries Production

The projection of possible futurechanges in fishery production for coastalLouisiana is based solely on landscapechange model predictions previouslydiscussed in Chapter 5. The keyparameters in making those projectionswere percent and pattern of wetland lossin each mapping unit. It should berecognized that numerous other factorswhich could not be forecast, such aschanges in water quality, fishery harvestlevels, wetland development activities

(e.g., dredging and filling), and blockagesof migratory pathways also couldnegatively impact fishery production. Because of the potential for greatinaccuracy in predicting land loss andfishery population changes 50 years intothe future, especially when considered ata mapping unit scale, discussion of futurechanges is presented as a coastwideassessment with reference to specificunits to exemplify those changes. Projected trends in production arepresented for each guild and for eachmapping unit in the Appendices C-F.

Marine Assemblage

Within the marine assemblage anddependent on individual species habitatrequirements, habitats utilized by speciesof this assemblage are expected toexpand as barrier islands submerge, landand land platforms subside, saline marshdeteriorates and retreats, tidal prismsincrease, and higher salinity watersintrude farther inland. This habitat shiftwould increase the area of near shorehabitat available for the marineassemblage. Accordingly, the futureprojections do not reflect adverseproduction impacts typically associatedwith land loss, and in a number of casesincreases are forecast. As shallow marinehabitat expands, however, it is likely thatthe forage base, composed partly ofestuarine-dependent species, woulddiminish. It is possible that, even thoughhabitat conditions would remain suitable,a reduction in populations of estuarine-dependent forage species would causedecreased production of the marineassemblage.

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Estuarine Resident Assemblage

As barrier islands erode and wetlanderosion and submergence continue overthe next 50 years, it is likely that highersalinity levels will occur at more inlandlocations. To remain in preferred salinityzones, the estuarine resident assemblagewill continue to be displaced northwardas salinity shifts occur. The magnitudeof population relocations will be relatedto the salinity tolerance and habitatpreferences of individual species withinthe assemblage. The American oyster isespecially sensitive to salinity changesbecause of its susceptibility to attack bypredators and parasites as averagesalinities increase above 15 parts perthousand. Overall, as preferred wetlandhabitats deteriorate, detrital based foodsources diminish, and zones of optimalsalinity are reduced or shift to areashaving otherwise unsuitable habitats,populations of species within theAmerican oyster guild will decline.

Estuarine Dependent Assemblage

Guilds within the estuarine-dependentassemblage can tolerate a variety ofsalinity conditions, so salinity changealone should not significantly affectpopulations. Production of many of theguilds, however, is closely associatedwith the areal extent and interspersion ofvegetated, intertidal wetlands. In areassuch as the Terrebonne Wetlandsmapping unit of Region 3, estuarinewetlands are already highly fragmented(high water-marsh interspersion). Thepredicted continued marsh loss withinsuch mapping units would result inreduced wetland habitat availability anda decline in production. In areas where

extensive marshes exist, the pattern offuture marsh loss would influence howthat loss impacts productivity. A gradualloss of marsh edge (enlargement of waterbodies) should not have a major short-term effect.

Where land loss occurs in the form ofinternal marsh break-up (formation ofnumerous small water bodies in anotherwise continuous marsh), productioncould be enhanced by increased habitataccessibility and the export of nutrientsand plant detritus. The Johnson’s Bayoumapping units in Region 4 provide anexample of such a loss pattern andassociated fishery production increases. Even in these areas, however, asdeterioration continues beyond the year2050, production would decline. Overall,the matrices (Appendices C-F) indicatethat wetland erosion and fragmentationwill cause a reduction in the productivityof guilds within the estuarine-dependentassemblage.

Freshwater Assemblage

Freshwater assemblages have a lowtolerance for salinity. They generally arefound in coastal areas having salinities of2 parts per thousand or less. As highersalinity water encroaches into previouslyfresh wetlands, species within thefreshwater guilds would be displaced. The ability of these guilds to relocate tosuitable habitat is restricted by landelevation. That is, at some point thefreshwater aquatic habitats of the coastalarea grade into nonaquatic habitat. Populations within the largemouth bassand channel catfish guilds may not begreatly affected in areas having arelatively low predicted rate of wetland

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loss. The total area of suitable,freshwater habitat, however, willdiminish as marsh and barrier islandbuffers between the Gulf of Mexico andfresh to low salinity zones deteriorate. Reduction of the area available for useby the freshwater assemblage guildswould result in an overall reduction ofthose populations. Only in the area ofAtchafalaya and East Cote Blanche Baysand in the vicinity of river diversionoutfall sites is there an expectedexpansion of freshwater fishery habitatby 2050.

Summary

In general, populations within the marineassemblage should remain relativelysteady unless there is a decline in foodavailability related to the loss of wetlandhabitat. Species within the estuarineresident and estuarine dependentassemblages will decline based onhabitat loss predictions for the year 2050. The two guilds representing thefreshwater assemblage are predicted tohave steady to decreasing populationlevels except in those mapping units withsignificant freshwater inflows.

Wildlife

Louisiana’s coastal wetlands, extendingfrom the forested wetlands at the upperend to the barrier shorelines borderingthe gulf, provide a diverse array ofhabitats for numerous wildlifecommunities. In addition to fulfilling alllife cycle needs for many residentspecies, coastal wetlands providewintering or stopover habitat formigratory waterfowl and many otherbirds. The bald eagle and brown pelican,

protected by the Endangered Species Act,are recovering from very low populationsexperienced over the last three decades. Increasing populations for those twospecies are projected to continue in thefuture, independent of near-term wetlandchanges. The fate of other species groupsin coastal Louisiana will be influenced byhabitat conditions there. These groupsinclude migratory birds, such as winteringwaterfowl, which rely on the abundantfood supply in coastal wetlands to storesufficient energy reserves for migrationand nesting. The prediction of extensiveland loss and habitat change by the year2050 prompted an examination of theeffect of such losses and changes in theabundance of wildlife.

Methodology

To assess the recent trends and futureprojections of wildlife abundance withinthe Coast 2050 study area (Appendices B-F), 21 prominent wildlife species and/orspecies groups were identified: (1) brown pelican, (2) bald eagle, (3) seabirds, (4) wading birds, (5) shorebirds, (6) dabbling ducks, (7) diving ducks, (8) geese, (9) raptors,(10) rails, gallinules, and coots, (11) other marsh and open waterresidents, (12) other woodland residents,(13) other marsh and open watermigrants, (14) other woodland migrants,(15) nutria, (16) muskrat, (17) mink, otter,and raccoon, (18) rabbit, (19) squirrel, (20) white-tailed deer, and(21) American alligator. A matrix wasdeveloped for each region to present thefunction, status, trend (over last 10 to 20years), and projection (through the year2050) for the above listed species and/orspecies groups for each habitat type

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within each mapping unit. Habitat typeswhich occupied less than 5% of a givenmapping unit were excluded unless thathabitat type was viewed to be unique orunless it performed a critical function.

Information displayed in the matrices(see Appendices C-F for Regions 1-4,respectively) represents commonunderstandings of the selected speciesand/or species groups, fieldobservations, some data, and recent andprojected habitat changes, allsynthesized by wildlife biologists fromthe Louisiana Department of Wildlifeand Fisheries, U.S. Fish and WildlifeService, and the Natural ResourcesConservation Service.

Because the amount of informationcontained in the matrices is quiteextensive (21 species or species groups,140 mapping units, and up to sevenhabitat types per mapping unit), ageneral discussion is presented, byregion, of only those instances wherespecies or species groups have beendecreasing or increasing in abundanceover the last 10 to 20 years, or areprojected to decrease or increase inabundance through the year 2050. If aspecies or species group is not discussedwithin a region, the abundance of thatspecies or species group has beengenerally steady over the last 10 to 20years and is expected to remain generallysteady through the year 2050.

The projection of wildlife abundancethrough the year 2050 is based almostexclusively on the predicted conversionof marsh to open water and the gradualrelative sinking and resultantdeterioration of forested habitat

throughout the study area. Suchpredictions may or may not prove to beaccurate. Additionally, numerous otherfactors including water quality, harvestinglevel, and habitat changes elsewhere inthe species’ range cannot be predictedand were not considered in theseprojections. Therefore, the projectionspresented below and in the Appendicesare to be viewed and used with caution.

Region 1 Wildlife Trends and Projections

Trends

Brown pelican and bald eagle abundancesare increasing. Wading bird abundancehas increased in all but four mappingunits which surround Lake Borgne. Dabbling duck, diving duck, rail, gallinule,and coot numbers are declining in CentralWetlands and South Lake Borgne. Theabundance of raptors and other woodlandspecies are increasing in forestedwetlands. Alligator abundance has beenincreasing in the upper basin anddecreasing in the lower basin.

Projections

Brown pelican and bald eagle numbersare projected to increase in areaspresently occupied. Seabird abundance isexpected to decrease in the lower basinand in the Bonnet Carré and LaBrancheWetland mapping units. Wading birdnumbers are expected to decrease in thefour mapping units which surround LakeBorgne. The numbers of dabbling ducks,diving ducks, geese, rails, gallinules, andcoots are expected to decline in theManchac and East Orleans Land Bridgeareas, Central Wetlands, and South Lake

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Borgne. The abundance of other birdsutilizing marsh and open water habitatsis expected to decrease in three units onthe periphery of Lake Borgne and in theLaBranche Wetlands.

The abundance of raptors and otherwoodland species is expected todecrease in forested habitats. Raptorabundance is expected to decrease forfive marsh-dominated units around LakePontchartrain and Lake Borgne. Furbearer and alligator numbers areexpected to decrease in the lower basin. Alligator abundance in the upper basin isexpected to increase. In mapping unitssurrounding Lake Maurepas, in CentralWetlands, and in South Lake Borgne,squirrel, rabbit, and white-tailed deerabundance are expected to decrease.


Trends

Brown pelican and bald eagle abundanceare increasing. Seabird abundance isdecreasing in areas of high land loss. Dabbling duck and diving duck numbersare declining in the brackish and salinemarshes of the central and lowerportions of Region 2, declining in theless active parts of the Mississippi Riverdelta, and increasing in the vicinity offreshwater diversions. Goose numbersare declining in less active parts of thedelta. Rail, gallinule, and coot trends aresimilar to that of dabbling ducks, exceptthat Cataouatche/Salvador and Gheenshave increasing numbers. Theabundance of other birds using marshand open water habitats is declining in

areas of high land loss. Raptorabundance has increased in forestedhabitats and decreased in deterioratingmarshes. Furbearer and alligator numbersare decreasing in areas experiencing highland loss.

Projections

Brown pelican and bald eagle numbersare projected to increase in areaspresently occupied. Seabird abundance isexpected to decrease in areas of high landloss. Wading bird and shorebirdabundance are expected to decrease in theregion except in areas influenced by riverdiversions. The numbers of dabblingducks, diving ducks, rails, gallinules, andcoots are expected to increase in thevicinity of freshwater diversions anddecline in the other central and lowerregion marshes. Goose abundance isexpected to decrease in the less activedelta areas.

The abundance of other birds usingmarsh and open water habitats isprojected to decrease in deterioratingwetlands and increase in projected land-building areas such as West Bay. Decreased numbers of raptors and otherwoodland birds are expected across theregion except in areas influenced by riverdiversions. Furbearer and alligatornumbers are projected to decrease inareas expected to experience high landloss. Squirrel abundance is expected todecline throughout Region 2. Rabbit andwhite-tailed deer numbers are expected todecline in much of the fresh swamp,hardwood forest, and central and lowermarshes.

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Trends

Brown pelican and bald eagle numbersare increasing. Seabird abundance hasdeclined in the Terrebonne-TimbalierBay area. Wading bird abundance hasincreased in stable wetlands and hasdecreased in deteriorated habitats. Shorebird abundance is decreasing in theTerrebonne-Timbalier mainland marshes. Goose numbers are increasing in thePenchant mapping unit and in themarshes near the Atchafalaya River. Rail, gallinule, and coot numbers aredecreasing in areas where marshes aredeteriorating. The abundance of raptorshas increased in forested wetlands.

Furbearer numbers have decreased in thedeteriorated wetlands of the Terrebonne-Timbalier Bay area and in the Mechant-de Cade mapping unit. Alligatorabundance is increasing in marsh-dominated mapping units which arestrongly influenced by the AtchafalayaRiver and is decreasing in units that haveexperienced high land loss.

Projections

Brown pelican and bald eagle numbersare projected to increase in areaspresently occupied. The abundances ofseabirds, wading birds, shorebirds,raptors, and other birds utilizing marshand open water habitats are expected todecrease in deteriorating wetland areas. Dabbling duck, diving duck, goose, rail,gallinule, and coot numbers are expectedto decline in the lower centralTerrebonne, lower eastern Terrebonne,

and Penchant marshes. The abundancesof raptors and other birds utilizinghardwood forests are expected todecrease.

Furbearer and alligator populations areexpected to decrease in deterioratingwetlands of the Terrebonne-TimbalierBay area and in Mechant-de Cade. Squirrel abundance is expected to declinethroughout Region 3, except in the Avocamapping unit. Rabbit and white-taileddeer numbers are expected to decline inmuch of the fresh swamp and hardwoodforest habitats and in the lower centralTerrebonne, lower eastern Terrebonne,and Penchant marshes.


Trends

In the vicinity of the gulf, Calcasieu Lake,and Sabine Lake, brown pelican numbersare increasing. Bald eagles have shown asmall but increased presence in the SouthWhite Lake unit. Wading bird abundanceis increasing in marsh habitats. In theMermentau Basin, dabbling duck anddiving duck abundances have declined inmapping units surrounding Grand Lakeand White Lake. In the Calcasieu-Sabinebasin, duck abundance has been generallyincreasing. Goose abundance isincreasing throughout much of Region 4. Alligator abundance is generallyincreasing in mapping units with low tomoderate salinity regimes and low tomoderate tidal energy.

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Projections

Brown pelican and bald eagle numbersare projected to increase in areaspresently occupied. Seabird abundanceis projected to decrease in marsh habitatsof the Calcasieu-Sabine Basin. Decreases in wading bird abundance areexpected in marsh habitats of eightCalcasieu-Sabine Basin mapping unitsand six Mermentau Basin units. Decreased shorebird abundance isexpected in marsh habitats in 11Calcasieu-Sabine Basin mapping unitsand 11 Mermentau Basin mapping units. The abundances of dabbling ducks,diving ducks, geese, rails, gallinules, andcoots are expected to decline in mapping units surrounding Grand Lake and WhiteLake, and in other mapping unitsthroughout Region 4 where conversionof marsh to open water is expected.

Decreased abundance of other birds utilizing marsh and open water habitats isexpected in marsh habitats in 17Calcasieu-Sabine basin mapping unitsand 12 Mermentau Basin mapping units. The abundances of raptors and otherbirds utilizing forested habitats areexpected to decrease. The abundance offurbearers is expected to increase in theCameron-Creole Watershed mappingunit. Alligator numbers are expected toincrease in six low salinity mapping unitsand two mapping units where salinity andwater level regimes are now manipulated(Cameron-Creole Watershed and WestBlack Lake). In mapping units with highland loss projections, rabbit and white-tailed deer numbers are expected todecline.

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Table 6-1. Representative fish and invertebrate guilds of coastal Louisiana.

Species (guild)Life stage Habitat

preferenceSalinity

preference

Primaryhabitat

functionSeasonal

preference

EM SH DW FS F I B SA S NU FO SP SU FA WI YR

Marine assemblage

Spanishmackerel

Adult

Juvenile

Estuarine dependent assemblage

Red drum Adult

Juvenile *

Black drum Adult

Juvenile *

Spottedseatrout

Adult

Juvenile *

Gulfmenhaden

Adult

Juvenile *

Southernflounder

Adult

Juvenile *

Whiteshrimp

Subadult

Juvenile *

Brownshrimp

Subadult

Juvenile *

Blue crab Adult

Juvenile * *

Estuarine resident assemblage

American oyster * *

Freshwater assemblage

Largemouth bass

Adult *

Juvenile

Channelcatfish

Adult *

Juvenile

Habitat preference— EM=emergent marsh; SH=shallow water; DW=channel, open water > 6 ft; FS=fresh swampSalinity preference— F=fresh; I=intermediate; B=brackish; SA=salinePrimary habitat function— S=spawning; NU=nursery; FO=foragingSeasonal preference— SP=spring; SU=summer; FA=fall; WI=winter; YR=year round<All preferences denoted by block shading>* Indicates immigration period for marine transient species and spawning season for resident species.

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CHAPTER 7

ECOSYSTEM MANAGEMENT STRATEGIES

Strategic Goals

Because natural processes created thehighly productive wetlands in coastalLouisiana, reestablishment of theseprocesses is essential to achievesustainability. Reestablishment does notimply controlling nature but does requireconstructive use of the forces thatformed coastal Louisiana (the rivers,rainfall, and the gulf). Neither doesreestablishment imply a return of thecoastal system to a pristine condition,because too much has changed for thatto occur. The intent is to designrestoration strategies based on ecologicalprinciples so the future coast will havethe productivity and other desirablefeatures of a highly-valued naturalsystem.

There are three strategic goals that mustbe achieved in order to restore thecoastal ecosystem. Each goal isdiscussed below. The regionalecosystem strategies, describedsubsequently, are intended toaccomplish these goals.

Goal 1: Assure vertical accumulation to achieve sustainability

The natural, long-term productivity ofLouisiana’s coastal wetlands hasoccurred because, over a large area andover time measured in centuries, the

ecosystem maintained itself against thenatural forces (such as subsidence anderosion) that cause marsh loss. Self-maintenance is the most essentialattribute of “what the ecosystem needs.” Failure to achieve self-maintenance inthe system means either the systemcannot be sustained, or the system mustbe maintained artificially with largeongoing investments of labor, energy,and materials.

To achieve self-maintenance, sustainablemarshes must accumulate sedimentand/or organic matter at a rate thatequals or exceeds the combined effect ofsea-level rise and subsidence. Thisupward growth in the land surface, tocounteract sinking, is known as verticalaccumulation. Delta building is onenatural process of accumulation of newland. For established marshes, verticalaccumulation occurs through periodic,gentle marsh flooding and drainage thatpromote healthy vegetation and largerates of organic production. It is also important to protect otherwise self-sustaining wetlands from excessiveerosional forces.

Goal 2: Maintain estuarine gradient to achieve diversity

Following sustainability, a secondessential characteristic that makes thenatural system so productive is its

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diversity of habitats and the consequentdiversity of fish and wildlife resources. These habitats include swamps, marshesof various salinities, and the moreemergent landforms (natural andartificial levees, chenier ridges, and barrier islands). With diversity, theecosystem is capable of providing a widearray of outputs and is resilient toadverse changes.

A dynamic salinity gradient in eachestuary is the fundamental driving forcethat creates natural ecosystem diversity.Significant freshwater input must occurat the upper end of each estuary andmust flow seaward to grade intoincreasingly saline and tidally dominatedflow at the gulf end of the estuary, wherethe system is partially contained byemergent land (such as barrier islands orchenier ridges). With a salinity gradientcomes the gradation of fresh-intermediate-brackish-saline vegetationand associated variations in fish andwildlife habitat. The other features ofecosystem diversity, such as the moreemergent landforms, are naturaloutgrowths of the delta-building andchenier cycles.

Goal 3: Maintain exchange andinterface to achieve system linkages

Ecosystem linkages are the pathways bywhich energy, materials, and organismsare transferred and mixed among theecosystem components. Effectiveinterconnections are needed to support afood chain that is diverse and highlyproductive. Examples include migrationof saltwater organisms intocomparatively fresher marshes as part oftheir natural reproductive cycle; the

normal export of surplus organic marshdetritus to sustain the estuarine foodchain; and overflow of fresh water (withnutrients and sediments) into marshes ina natural flow regime.

Optimal linkages require that thelandforms and hydrology of theecosystem allow for efficient exchangeof energy and materials between themarshes and estuaries. In turn, this isachieved by habitats that have stableedges and that are naturally interspersedwith other habitats, and by a hydrologicregime that maintains the naturalrhythms of the coast— including tidalcycles, storms, and river floods.

The regional strategies discussed belowapply these three strategic goals indifferent ways, depending on the specificneeds of ecosystems in different areas.The relative role of the regional strategiesin meeting the ecosystem needs isbroadly categorized, according to theestimated amount of marsh benefitted,as minor (< 1,000 acres), moderate(1,000-5,000 acres), major (5,000-10,000acres) or substantial (>10,000 acres). Further details about specific strategiesfollow; very broadly, any given strategyincludes one or more of the followingapproaches.

C Enhance the ecosystem by usingresources more efficiently . In someareas, especially those with strongand positive riverine influences, theintegrity of the natural system isintact and the wetlands areconsidered sustainable through 2050with little or no further intervention. Strategies are designed to make

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more effective use of the availableresources.

C Maintain the ecosystem byaddressing known risks . In someareas, the ecosystem is now thrivingbut is at risk of losing itssustainability by 2050. Theseecosystems may be at risk from thepredicted loss of adjoiningwetlands, shorelines, barrier islands,or levee ridges that now provideintegrity to the ecosystem. Therisks may also relate to prospectivechanges in existing hydrologicmanagement. In such areas,strategies aim to reduce risks andpromote hydrologic conditions thatare favorable to sustainability,diversity, and exchange.

C Recover the ecosystem by reversingthe loss process . Large areas of thecoast exist where the ecosystem haslost some of its integrity and theemergent wetlands are no longerself-maintaining. Where these areashave a platform of intact (butperhaps declining) vegetation, it ispossible that the wetlands couldreturn to self-maintainingconditions. The strategies are torecover sustainability throughrestoration actions that recreate thelost aspects of system integrity,reduce existing vegetation stresses,and/or stimulate verticalaccumulation.

C Rebuild the ecosystem by creatingnew wetlands. Finally, in someparts of the coast, the ecosystemhas degraded to the point that

virtually all of the ecosystemintegrity is lost and there is novegetative substrate upon which torecover sustainable conditions. Consequently, if emergent wetlandsare desired, they will need to benewly built, as through a new deltalobe or marsh creation project. Alternatively, such areas wouldexist and function as an open watersystem.

Coastwide Common Strategies

The coastwide common strategies wereubiquitous to practically every mappingunit, so they are simply defined onetime, with the understanding that theywould be implemented as appropriate.They are explicitly recommended forsome mapping units where there isdeemed to be a compelling andimmediate need for such a strategy(Appendices C-F).

Beneficial Use of Dredged Material from Maintenance Operations

Five components are recognized: (1)inventory unused material, (2) assesssuitability of material for beneficial use(e.g., grain size, contaminants), (3)identify sites to benefit from unusedmaterial, (4) address the Federal standardfor beneficial use, and (5) secure fundingto utilize unused material if beneficialuse is more costly than the Federalstandard. Some aspects of this beneficialuse are programmatic in nature in thatthey do not result in projectdevelopment and construction. Thebeneficial use strategies listed in theregional and mapping unit tables

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(Appendices C-F) refer to the physicalact of building wetlands with dredgedmaterial rather than the programmaticaspects, discussed later in this document(Chapter 8).

Dedicated Dredging for Wetland Creation

Wetland habitat creation using dredgingtechnology is a viable strategy across thecoastal zone to build land wheretraditional marsh building processes donot occur or are infeasible. This strategydiffers from beneficial use ofmaintenance dredged material in thatmaintenance dredged material fromnavigation channels or other permittedactivities is not the intended sedimentsource. As a strategy, the primarypurpose of dedicated dredging is the utilization of dredged material to restore,create, or enhance coastal wetlands.

Herbivory Control

Nutria, and occasionally muskrat,populations can become so high incertain areas of Louisiana’s coast thatthey actually destroy marsh, resulting inits conversion to open water. Thisstrategy is aimed at reducing the severelevels of marsh destruction by increasingtrapping incentives, developing bettermarkets for nutria, etc.

Stabilization of Major Navigation Channels

The loss of wetlands resulting from thedirect effects of bank erosion alongLouisiana’s nine major navigationchannels in the coastal zone is estimated

to be in excess of 35,000 acres. Theneed for stabilization in critical areas hasbeen noted in all four Coast 2050regions.

Maintenance of Bay and Lake Shoreline Integrity

This strategy includes an array ofshoreline protection technologies inlocations where excessive erosion of bayand lake rims would expose interiormarshes to increased rates of erosion orsevere hydrologic change. The strategyis not intended to armor all shorelines orto prevent normal shoreline retreat androllover.

Management of Pump Outfall for Wetland Benefits

As the number of pumps increasesthroughout the coast, so do theopportunities to benefit wetlands whileimproving the quality of the dischargedwater. Water quality improvementusually involves introducing thedischarge into wetlands, rather thandirectly into waterways, in a controlledfashion for filtering.

Vegetative Planting

Planting projects have been used forover a decade in Louisiana with a highdegree of success. Vegetative plantingscan stabilize banks and reestablishwetlands in some areas. Added benefitsinclude increased overall plantproductivity in the areaand creation of primehabitat for wildlife andfish.

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Maintain or Restore Ridge Functions

Coastal ridges resulting from abandonedshorelines or natural levees are a criticalstructural component of our estuaries.The repair or maintenance of these toprotect or improve the hydrology of thecoast is recommended at numerouslocations.

Terracing

Terracing, accompanied by vegetativeplanting, is an effective means of marshhabitat creation in areas with soils ofsuitable mineral content. Functions andvalues of terraces include nurseryhabitat, fetch reduction, and sedimenttrapping in addition to promotingconditions conducive to growth ofsubmerged aquatic vegetation.

Region 1 Strategic Plan

Background

Region 1 encompasses the LakePontchartrain Basin, which extends fromthe Mississippi River on the west to theChandeleur Islands on the east, and fromthe Prairie Terrace on the north to theMississippi River Gulf Outlet (MRGO)on the south. It covers portions of thefollowing parishes: Livingston,Tangipahoa, St. Tammany, St. Bernard,Orleans, Jefferson, St. Charles, St. Johnthe Baptist, St. James, and Ascension.

The region can be divided into threesubbasins. The Upper Basin consists ofthe 110,000 acres of bottomlandhardwoods, 191,630 acres of swamps,12,700 acres of fresh marshes, and about

400 acres of intermediate marshes that liewest of the Pontchartrain/MaurepasLand Bridge. The Middle Basin contains21,850 acres of swamps, 20,000 acres offresh marshes, 27,300 acres ofintermediate marshes, and 42,000 acresof brackish marshes surrounding LakePontchartrain. The Lower Basin consistsof 90 acres of swamps, 2,000 acres offresh marshes, 68,900 acres of brackishmarshes, and 79,700 acres of salinemarshes around Lake Borgne and nearChandeleur Sound.

The region contains Lakes Pontchartrain,Maurepas, and Borgne, which governhydrology and drainage patternsthroughout the region. The Amite andTickfaw Rivers, Bayou Manchac andother rivers drain into Lake Maurepas. These contribute to significant watermovement within the area. LakePontchartrain is affected by freshwaterinflows from Pass Manchac, North Pass,and the Tangipahoa, Tchefuncte, andBogue Falaya Rivers, some bayous, andthe Bonnet Carré Spillway. The lowerbasin contains many tidal channels. Major navigation channels include theMRGO and the Gulf IntracoastalWaterway.

Habitat Objectives

Generally, parish governments and citizens in Region 1 are more concernedwith maintaining present habitats andcurrent levels of productivity in theregion than with making massivechanges (Fig. 7-1, 7-2). Someconversion of intermediate and brackishmarshes to fresh marshes is deemed

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warranted in the Manchac and NorthShore marshes and around the PearlRiver mouth. Open water in the interiorof the forested wetlands in and aroundLake Maurepas is also recommended forreconversion to forest. Forestedwetlands in the central wetlands,currently stressed by high salinity, arealso denoted for expansion. Some of thesaline marshes in the Biloxi Marshmapping unit are recommended forconversion to brackish marsh.

Regional Ecosystem Strategies

Restore Swamps

1. Small Mississippi River diversion atBlind River with outfall management .The swamps in the Upper Basin aredying because they are subsiding,flooding, and lacking sediment andnutrients. A diversion of no greater than2,000 cubic feet per second (cfs) at BlindRiver with outfall management (restoringnatural drainage patterns by gappingspoil banks, plugging canals, andmaintaining culverts) is proposed (Fig.7-2). This strategy is intended to preservethese swamps by reducing flooding andproviding them with nutrients. At thepresent time, the extent of possiblewetland benefits is uncertain.

2. Small Mississippi River diversion atReserve Relief Canal with outfallmanagement . A diversion of no greaterthan 2,000 cfs at the Reserve ReliefCanal with outfall management isexpected to preserve minor acreage inthese swamps by reducing flooding andproviding them with nutrients.

3. Restore natural drainage patterns . In areas of the Upper Basin wherediversions are not built, natural drainagepatterns would be restored by gappingspoil banks, plugging canals, andmaintaining culverts. For instance, if theculverts under U.S. Highway 51 wereproperly maintained, the swamps to thewest would be less stressed by pondedwater. This strategy is projected topreserve minor amounts of swamp.

4. Provide diversion-related floodprotection where needed . Additionalflood protection and drainage would beprovided to any developed areas in theUpper Basin that would be threatened bydiversion-related flooding. Low leveeswould be provided at thewetland/nonwetland interface withpumped drainage. This strategy isnecessary before any of the diversionscan be built, and its benefits to wetlandswill be indirect.

Restore/Sustain Marshes

5. Small diversion from the MississippiRiver through the Bonnet CarréSpillway by opportunistically removingpins from the water control structure . The wetlands along the south shore ofLake Pontchartrain have a low loss rate,probably because the water divertedthrough the Bonnet Carré Spillway forflood control provides sediment andnutrients. Authorization would besought for removing pins from theBonnet Carré Flood Control Structurewhen the Mississippi River is high. Thediverted water would provide additionalnutrients and sediment to the wetlandsadjoining Lake Pontchartrain. By

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removing pins early in the year, the freshwater and nutrients would be diverted tothe lake before the warm temperaturescould cause large algal blooms. Some ofthe additional water would be moved tothe west, perhaps along the OldHammond Highway borrow pit, to reachthe Manchac wetlands. This strategy isexpected to prevent the loss of amoderate amount of wetlands.

6. Small diversion of Mississippi Riverwater into La Branche Wetlands . Asmall diversion from the MississippiRiver could be made into the southernLa Branche marshes. The diversion islikely to prevent the loss of a moderateamount of wetlands.

7. Diversion from Jefferson Parishdrainage into La Branche Wetlands .Drainage water would be pumped intothe swamps or marshes whereverfeasible. Pumping water from theJefferson Parish drainage canal isproposed to get additional fresh waterand nutrients into the La BrancheWetlands. This strategy is expected topreserve a minor amount of wetlands.

8. Wetland sustaining diversion fromthe Mississippi River near Violet oncethe MRGO is closed . A 2,000 to 5,000cfs diversion from the Mississippi Riverthrough the Violet Canal to sustain theCentral Wetlands and Biloxi Marsheswould be built. Such a diversion couldnot be effective until the MRGO isclosed. This strategy is estimated topreserve moderate amounts of themarshes in the Central Wetlands andadjacent to Lake Borgne. These marshesprovide significant hurricane bufferingfor the New Orleans metropolitan area.

9. Dedicated delivery of sediment formarsh building . Material could bepumped from adjacent lakes or rivers tocreate marsh in several units(Tchefuncte, Tangipahoa, and PearlRiver mouths, Eloi Bay, and Biloximarshes). This strategy is projected tocreate a moderate amount of marsh.

Protect Bay and Lake Shorelines

10. Maintain shoreline integrity ofLake Pontchartrain . Maintaining theshoreline integrity of Lake Pontchartrainneeds to be addressed. Lake shorelineprotection could be in the form ofstructural means (wave busters, gobimats, rip-rap, etc.) or non-structuralmeans (vegetative rolls or mats,vegetative plantings, etc.). This strategyis expected to preserve a minor amountof marsh.

11. Maintain shoreline integrity ofLake Borgne and protect shoreline ofthe Biloxi Marshes . Maintaining theshoreline integrity of Lake Borgne needsto be addressed. Lake shorelineprotection could be achieved bystructural means (wave busters, gobimats, rip-rap, etc.) or non-structuralmeans (vegetative rolls or mats,vegetative plantings, etc.). This strategyis projected to preserve a minor amountof marsh. Shoreline protection of theBiloxi Marshes is necessary becauseover 18% of the area will be lost by theyear 2050 if nothing is done. Shorelineprotection of the most seriously erodingareas is projected to preserve a moderateamount of marsh.

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Restore and Maintain Barrier Islands

12. Maintain Chandeleur Islands ifnecessary . The Chandeleur Islandsprovide unique habitat in the basin:beaches, dunes, marshes, mudflats, andbeds of submerged aquatic vegetation(SAV). The islands are fairly stable, butthey breach regularly and are movingnorth and west. The islands wereseriously damaged by HurricaneGeorges in 1998. Portions of theChandeleurs are protected with awilderness designation that prevents anyrepair. Coordination with the U.S. Fishand Wildlife Service should occur and arequest for a special exemption fromCongress to allow island maintenanceshould be sought. Islands would berestored with material from offshore orfrom the maintenance of the MRGO.This strategy would maintain the 1990acreage on the islands.

Maintain Critical Landforms

13. Maintain Eastern Orleans LandBridge by marsh creation and shorelineprotection. This land bridge protects thewetlands surrounding LakePontchartrain from higher salinity andhigher energy waters. It is a fairly stablelandform at the present time. If itappears that the land bridge is at risk,major efforts would be made to stabilizeit. Marsh would be created and shorelineprotected by dedicated dredging orbeneficial use. Vegetative plantingscould also be used. SAV beds would berestored. This strategy is estimated topreserve moderate amounts of marsh.

Special Problems—Resolve the MRGO Problem

14. Close MRGO to deep draftnavigation when adequate containerfacilities exist on the river. The MRGOis perceived as a major problem in thePontchartrain Basin. Wave erosioncauses a 15-foot per year loss along 37miles of the north bank. When theMRGO was completed in the 1960’s,salinity increased in the basin, causingmassive environmental damage.Currently, the MRGO is the only accessto container facilities on the Inner HarborNavigation Canal. However, only 2-3large ships per day use the waterway. Some container facilities have just beenbuilt on the Mississippi River in the NewOrleans area, but they are generally fullybooked.

A large new Millennium Port, includingcontainer facilities, is proposed inPlaquemines Parish. Once there areadequate container facilities on the river,the MRGO would be closed to deepdraft navigation. The closure could beachieved by a structure (gate or weir) atthe La Loutre ridge that would allow thepassage of shallow-draft navigation butreduce salinities coming up the MRGO.In addition, the possibility of restoringthe ridges at Bayous Bienvenue, Dupre,and Yscloskey should be studied. Thestrategy of actually closing the channelto deep draft shipping is expected topreserve minor amounts of marsh.

15. Expedite planning for theMillennium Port . The Millennium Port,a new deep draft port underconsideration for construction in

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Plaquemines Parish, would allow closureof the MRGO to large vessels. Planningfor the Millennium Port should startimmediately.

16. Stabilize the entire north bank ofthe MRGO. The U.S. Army Corps ofEngineers (USACE) has placed somerock along the north bank of the MRGOunder various authorities. Authorizationand funding for more rock along thenorth bank would be sought. Inaddition, dredged material wouldcontinue to be used beneficially behindthe rock. This strategy is projected toprevent the loss of a moderate amount ofmarsh.

17. Acquire oyster leases and createmarsh in the southern lobes of LakeBorgne. Oyster leases in the twosouthern lobes of Lake Borgne (atBayous Dupre and Yscloskey) would bepurchased and marsh created in theselobes by beneficial use of dredgedmaterial. Rock dikes would contain thecreated marsh. The marsh would bemaintained with maintenance material. This strategy is expected to create andpreserve major amounts of marsh.

18. Constrict breaches between MRGOand Lake Borgne with created marshes . The rock needed to contain the createdmarsh would be placed so as to reducethe cross section of Bayous Dupre andYscloskey. This constriction wouldreduce the salinity in Lake Borgne andthe Biloxi Marshes. This strategy wouldimprove the area slightly for oysters, butwetland benefits have not yet beenestimated.

19. Construct a sill at Seabrook . During most summers, a large area ofLake Pontchartrain has very littledissolved oxygen at the bottom. Thisanoxic area is caused by salinitystratification due to the MRGO. Thisanoxic condition could be solved byconstructing a sill at Seabrook. Thisstrategy would improve fisheries in LakePontchartrain.

Sequencing of Regional Strategies

Near Term (1-5 years)

In the near term, easily constructedstrategies should be implemented. Also,any strategies that are a necessary firststep for other strategies should be built.

The possible benefits of the MississippiRiver diversion at Blind River should beanalyzed quickly because the cypressswamps west of Lake Maurepas aresome of the most severely stressed in thebasin. If the diversion is found to befeasible, the diversion-related floodprotection must first be provided. Thisdiversion and its outfall managementshould be closely monitored to verify itseffectiveness.

Removing the pins from the BonnetCarré Spillway when waters are high is avery easily implemented strategy andshould be started as soon asauthorization can be acquired. Pumpingfrom the Jefferson Parish drainage canalsinto La Branche Wetlands should bestarted in the near term and monitored tosee if this strategy is appropriate foradditional areas. The small diversionfrom the Mississippi River into LaBranche Wetlands should be built.

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Continued use and management of theexisting Violet siphon is recommendeduntil the larger project is built. Criticallyeroding shorelines of Lakes Borgne andPontchartrain, such as those along theshorelines of the East Manchac LandBridge and the East Orleans LandBridge, should be maintained, as shouldthe eastern shoreline of Biloxi Marshes.

Construction of a sill at Seabrook shouldbe accomplished in the near future. Dedicated delivery of sediment shouldbe initiated in several units.

The north bank of the MRGO should bestabilized as soon as possible. Negotiations to purchase the oysterleases in the lobes of Lake Borgneshould be initiated. Then, when theUSACE needs new sites for beneficialuse of dredged material, these areas willbe available. Planning for theMillennium Port or alternatives shouldbe expedited. Potential benefits,including public safety, of closing theMRGO should be evaluated.

Dialogue should be initiated with theU.S. Fish and Wildlife Service todetermine the appropriateness of aspecific change in the wildernessdesignation for Breton National WildlifeRefuge that would allow restoration ofthe Chandeleur Islands after severedamage such as that from HurricaneGeorges in 1998.

Intermediate Term (6-15 years)

If the diversion at Blind River proveseffective in restoring swamps, theReserve Relief Canal diversion should bebuilt. If land loss appears to be

increasing on the Eastern Orleans LandBridge, restoration should be initiated.Studies should be initiated on the 2,000-5,000 cfs diversion proposed for theViolet Canal. Plans should be made forthe eventual closure of the MRGO with asill or gate at La Loutre.

Long Term (16-50 years)

The MRGO should be closed to deep-draft navigation. The wetland sustainingdiversion at Violet should be built.Possibilities for other freshwaterdiversions from the Mississippi Riverinto swamps should be sought if theprevious ones have proved effective.

Local and Common Strategies

There are some important local andcommon strategies in Region 1.Shoreline integrity could be maintainedin all mapping units (Fig. 7-3) aroundLakes Maurepas, Pontchartrain, andBorgne. Vegetative plantings of cypressand/or marsh grass could occur in nearlyall units. Dedicated dredging from LakesMaurepas, Pontchartrain, and Borgnecould be used to create marsh on theWest and East Manchac Land Bridges,in La Branche Wetlands, the EastOrleans Land Bridge, in South LakeBorgne and along the south shore ofLake Pontchartrain near Lincoln Beach.

Beneficial use of dredged material fromthe Tangipahoa bar channel could occur.Dredged material from the MRGO couldbe used to create marsh in South LakeBorgne, the Biloxi Marshes, and EloiBay.

Eloi Bay

Amite/BlindL ake

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St. John TheBaptist Eas t Area

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Region 1 Mapping Unit B oundaries10 0 10 20 Mile s

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Figure 7-3. R egion 1 m apping units.

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Submerged aquatic vegetation could berestored in Lakes Pontchartrain andMaurepas, in ponds on the East OrleansLand Bridge and in Chandeleur Sound. Wave breaks and rubble mounds couldmaintain shoreline integrity and improvefisheries habitat in Lake Pontchartrain. In Lake Borgne and the Biloxi Marshes,reef zones could enhance oysterproduction. Hydrologic restoration couldbe accomplished on the Manchac LandBridges East and West, the North Shoremarshes, the La Branche Wetlands, EastOrleans Land Bridge, Bayou Sauvage,the Central Wetlands, South LakeBorgne, the Biloxi Marshes, and EloiBay. See Appendix C for more detailson these local and common strategies.


Background

Region 2 includes the Breton Sound,Barataria Basin, and the MississippiRiver Birdsfoot Delta. It stretches fromthe MRGO on the east, to BayouLafourche on the west, to the MississippiRiver on the north and the Gulf ofMexico on the south. It covers all or partof the following parishes: St. Bernard,Plaquemines, Jefferson, Lafourche, St.Charles, St. James, St. John the Baptist,and Assumption.

It is an area with great habitat diversity.Extensive bottomland hardwood forests(90,000 acres) lie adjacent to theMississippi River and Bayou Lafourche.Over 146,000 acres of cypress-tupeloswamps cover the upper Barataria Basin.South of the swamps, vast marshesextend to the Gulf of Mexico in theMississippi Delta, Barataria and Breton

Basins (220,100 acres of fresh marshes,nearly 73,000 acres of intermediatemarshes, 214,500 acres of brackishmarshes, and 151,100 acres of salinemarshes). The fresh marshes are foundin the north, with a band of intermediatemarsh lying southward. The centralportion of the basins contain brackishmarshes; saline marshes fringe the Gulfof Mexico and Breton Sound. Thesouthern end of the Barataria Basin isbounded by a series of barrier headlands,islands and shorelines.

Habitat Objectives

Habitat objectives for the year 2050 werefirst suggested by parish governmentsand representatives of local coastal zoneadvisory committees. Then, as theRegional Planning Team developedstrategies, the habitat objectives wererevised to correlate with the strategies. These revised objectives were approvedby parishes. Because several largediversions into the Barataria Basin areproposed, the habitat objectives includefresh marsh extending south of LittleLake and across the basin through theMyrtle Grove unit (Figs. 7-4, 7-5).

Another objective is a new strip of freshmarsh parallel to the Mississippi Riverfrom West Point a la Hache to Veniceand near the river in American Bay. Aband of intermediate marsh gulfward ofthe fresh marsh with brackish marsh toits south is also desired. The onlyremaining saline marsh would be nearBarataria Bay. The barrier islands andshorelines would be restored. Regionalinterested parties prefer the MississippiRiver Birdsfoot Delta to remain as it isnow.

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Restore Swamps

1. Construct small diversions withoutfall management . A possible strategyto preserve the stressed upper basinswamps is to construct several smallsediment-rich diversions from theMississippi River. The outfall of thediversions should be managed to spreadthe water across the swamp, keep thewater moving and prevent ponding. Thenutrients and small amounts of sedimentbrought in by the river should slightlyincrease productivity and verticalaccretion in the swamps. This strategy isprojected to preserve a minor amount ofswamp habitat.

2. Restore natural drainage patterns .Another strategy consists of restoringnatural drainage by gapping spoil banksand plugging canals where these actionswould not cause adverse effects. Itwould be implemented in swamps whereit is not possible to provide freshwaterdiversions. It would be less effective inpreventing swamp loss than the previousstrategy which brought in fresh water.

3. Prevent diversion-related floodingand remove diverted waters from theupper basin . To add water to theswamps, flood protection must beprovided for developed areas, anddrainage improvements must be made sothe water can exit the upper basin. Localforced drainage should be provided atthe wetland/nonwetland interface so theswamps are separated from thedeveloped regions. Environmentallysound pumping plans should be

developed so storm water is filteredthrough the swamps. U.S. Highway 90should be raised and sufficient flap-gatedculverts should be installed so thatrainfall and the additional river watercould drain south by gravity.

Restore and Sustain Marshes

4. Use existing locks to divertMississippi River water . The existinglocks on the Mississippi River (Algiersand Empire) could be used to divert asmuch water as possible. At the presenttime, the USACE is releasing fresh waterthrough the Algiers Lock whenever thestage is low on the marsh side. Theexisting Harvey Lock cannot be used forsmall diversions, but when a replacementlock is needed for navigation, it shouldbe also designed so that small diversionswould be feasible. Implementation ofthis strategy is projected to preserve amoderate amount of marsh by 2050.

5. Manage outfall of existingdiversions. The siphons at Naomi andWest Pointe a la Hache already haveBreaux Act outfall management plans. These 20-year plans could be continuedthrough 2050. The authorized outfallmanagement plan at Caernarvon shouldbe implemented. A plan should bedeveloped for the Davis Pond diversion. This strategy is estimated to moderatelyreduce marsh loss by 2050.

6. Enrich existing diversions withsediment . This enrichment is difficult toengineer at the siphons because extrasediment could cause clogging. Thisconcept should be pursued at DavisPond and Caernarvon. Additional

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sediment is expected to preserve a minoramount of marsh by 2050.

7. Continue building and maintainingdelta splays. The Mississippi River iscreating marsh naturally on the eastbank, south of Bohemia and in theBirdsfoot Delta. The natural delta on theeast bank should be maintained. TheBreaux Act program of building andmaintaining delta splays in the BirdsfootDelta should be continued through 2050.This strategy is projected to create amoderate amount of new land.

8. Construct most effective smalldiversions . Several small diversionsfrom the Mississippi River have beensuggested as Breaux Act projects or arebeing studied in the Mississippi RiverSediment, Nutrient, and FreshwaterRedistribution Study. The most effectiveof these small diversions should beplanned and built (Upper Oak River,Amoretta, east and west of Empire). Theabove-mentioned diversions areprojected to prevent a moderate amountof marsh loss by 2050.

9. Construct sediment trap in theMississippi River south of Venice . Toreduce maintenance dredging inSouthwest Pass, the USACE is studyingthe possibility of a sediment trap southof Venice. Material that would normallybe dredged and “ocean dumped” couldbe used beneficially. The trap would bepumped out by a dustpan dredge andsignificant amounts of marsh areprojected to be created in the BirdsfootDelta.

10. Construct a delta-buildingdiversion in Myrtle Grove/Naomi area(15,000 cfs) . A delta-building diversionfrom the Mississippi River should bebuilt in the vicinity of Myrtle Grove orNaomi. Such a diversion is estimated tohave significant benefits by creating landand preventing loss in the central basinby 2050.

11. Construct delta-building diversionin Bastion Bay (about 15,000 cfs) . Adelta-building diversion of about 15,000cfs into Bastion Bay would create landand significantly reduce land loss in thevicinity. This strategy must addressoyster lease issues. The strategy wouldalso partially fill the borrow pit left fromthe construction of the New Orleans-to-Venice hurricane protection levee. Localinterested parties are concerned that thispit is increasing marsh loss and causingincreased salinities in the developed area.

12. Construct delta-building diversioninto Benny’s Bay (about 50,000 cfs) . Avery large diversion in the BirdsfootDelta between Main Pass and BaptisteCollette Bayou is projected to create asubstantial amount of land and reducefuture marsh loss.

13. Construct a delta-buildingdiversion into American Bay (20,000 to100,000 cfs) . This strategy is projectedto create/preserve a moderate amount ofland with a small diversion and asignificant amount with the largediversion. This strategy must addressoyster lease issues.

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14. Construct delta-building diversionthrough controlled crevasses intoQuarantine Bay. This strategy consistsof breaching the natural levee betweenBayou Lamoque and Fort St. Phillip toallow about 40,000 cfs to enterQuarantine Bay. Most of the sedimentwould be kept in Quarantine Bay by alow levee from California Point to SableIsland. This diversion is projected tocreate a significant amount of marsh andreduce loss in the vicinity. This strategyshould not significantly impact oysters.

15. Prevent the loss of bedload intodeep gulf waters off the ContinentalShelf by relocating the MississippiRiver Navigation Channel.One of the most significant ecologicalproblems in coastal Louisiana is the lossof major amounts of Mississippi Riversediments, including the bedload, intodeep gulf waters. This strategy woulddissociate riverine processes andnavigation and thus allow the MississippiRiver sediments to build and nourishmarshes. Navigation would be handledby a new channel exiting to the east orwest (but not north of Venice) with atleast a double set of locks. The strategyis expected to create a significant amountof land in the long term.

16. Dedicated dredging to create marshnear Louisiana Highway 1 . Thisstrategy would protect the vulnerablehighway with a 1,000-acre band ofmarsh in the Caminada Bay unit.

17. Dedicated delivery of sediment formarsh building in Caminada Bay. Themarshes adjacent to the southern end ofBayou Lafourche are deteriorating

rapidly and are far from any riverinesediment. One possible solutioninvolves pumping material from offshoreto the deteriorating marsh-pond complexto create significant areas of marshadjacent to Bayou Lafourche. Thisstrategy would not be self-sustaining, butit is projected to result in creating amoderate amount of marsh by 2050.

18. Construct a large conveyancechannel parallel to Bayou Lafourche todivert approximately 30,000 cfs tocreate a delta lobe in and near LittleLake. The potentially most effectivealternative for rebuilding this collapsedwetland system is to initiate a newsubdelta in the area. The subdelta couldbe accomplished by building aconveyance channel about one-third thesize of the Wax Lake Outlet that wouldleave the Mississippi River south ofDonaldsonville and parallel BayouLafourche at the Forty Arpent line(Gagliano and van Beek 1993; Gaglianoand van Beek 1998).

One branch of the channel would crossBayou Lafourche north of the GulfIntracoastal Waterway and build a deltain the Bully Camp area of Region 3. Theother branch would stay on the east sideof the bayou and nourish marshes orbuild a delta in and near Little Lake. Small diversions from the conveyancechannel could be directed into wetlandsin the northern portion of the basin. Themain conveyance channel could be usedas a floodway when the MississippiRiver is high.

After consolidation, material dredgedfrom the channel might provide a base

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for a new State Highway 1. Anypossible navigation features of thisstrategy must not impede the land-building capacity of the diversion.

This strategy is projected to createsignificant amounts of marsh in the LittleLake mapping unit, reduce marsh lossover the entire western portion of theBarataria Basin, and help preserveswamp in the upper basin.

19. Gap spoil banks and plug canals inlower bay marshes. Where determinedto be appropriate and feasible, spoilbanks would be gapped and canalsplugged to maximize sedimentdeposition in marshes adjacent to thebays in the lower portions of Breton andBarataria Basins. This strategy isestimated to prevent a minor amount ofloss.


20. Construct wave absorbers at theheads of bays . Low breakwaters wouldbe built at the heads of bays, asdescribed in the Barrier ShorelineFeasibility Study, to protect fringingmarshes. The possibility of continuingthese wave absorbers across thesouthern rim of the LakeWashington/Grand Ecaille unit and alsoacross the mouth of the Breton Basinwould also be considered. This strategyis projected to preserve a major amountof marsh.

21. Construct reef zones across bays.Reef zones would be constructed acrossbays. This strategy has no mappablemarsh benefits but would enhanceestuarine fisheries habitat.

Restore and Maintain Barrier Islands and Barrier Shorelines

22. Restore/maintain barrierheadlands, islands, and shorelines . TheFourchon headland, barrier islands, andbarrier shoreline are among the mostrapidly retreating shorelines in theregion. These areas would be restoredby the most cost-effective of the sandalternatives from the Barrier Shoreline Feasibility Study. This strategy isprojected to create moderate amounts ofmarsh and beach habitat by 2050. Additional unmappable benefits wouldbe gained by protecting, restoring, orcreating wooded areas critical forneotropical migrants.

23. Extend and maintain barriershoreline from Sandy Point toSouthwest Pass . The PlaqueminesParish Council has requested that thebarrier shoreline be extended fromSandy Point to Southwest Pass. Materialfrom the sediment trap (see Strategy 9)could possibly be used to build such ashoreline.

Maintain Critical Landforms - (CentralBasin Land Bridge)

24. Build entire Breaux Act land bridgeshore protection project . The southernportion of the Perot/Rigolettes unit mustbe kept intact to protect the marshesfarther north. This project should bebuilt and maintained through 2050. It isexpected to preserve a moderate amountof marsh by 2050.

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25. Preserve bay and lake shorelineintegrity on the land bridge . Thesouthern shores of Little Lake are indanger of breaching into interior marsh,and the Gulf Intracoastal Waterway isabout to breach into Lake Salvador onthe south shore of the lake. Theseshorelines should be stabilized. Thisstrategy is projected to prevent the lossof a moderate amount of marsh.

26. Dedicated dredging to create marshon the land bridge . This strategyconsists of dedicated dredging to createabout 1,000 acres of marsh north of theBayou L’Ours ridge to help stabilize theland bridge.

27. Build the Bayou Lafourche siphonand pump project, if cost effective . Thepossibility of a small pumped diversiondown Bayou Lafourche is being studied. The waters could be directed into theClovelly area to preserve a minoramount of land bridge marshes.



Authority should immediately beobtained to create a strip of marshadjacent to Highway 1. The USACE isinitiating a Reconnaissance Report forthe area from Donaldsonville to the Gulfof Mexico. This report will focus onflood control, wetland conservation andrestoration, wildlife and fish, andnavigation. Those responsible forimplementing the Coast 2050 programshould maintain close coordination withthis effort so the upper basin swampscan be restored as quickly as possible.

When the Barrier Shoreline FeasibilityStudy is finalized, authority should bequickly sought to construct therecommended alternative. The barrierheadlands, islands, and shoreline shouldbe restored as soon as possible. Waveabsorbers should be built to preservemarshes at the heads of bays.

Construction of a full Breaux Act landbridge project should be a high priority. Authority should be sought to stabilizethe southern shorelines of Lake Salvadorand Little Lake. Consideration shouldbe given to a dedicated dredging projectnear the Bayou L’Ours ridge underBreaux Act authority. If the BayouLafourche Pumping project is costeffective, it should be built.

The relocation of the Mississippi Rivernavigation channel to allow betterutilization of river sediments to createmarsh should be analyzed. Studiesshould be started immediately todetermine methods to prevent loss ofmassive amounts of sediments off theContinental Shelf.

The marshes in lower Barataria Basin areno longer sustainable without a massiveinfusion of sediment from theMississippi River. The Breton Basin andBirdsfoot Delta offer opportunities fordelta building diversions. The RegionalPlanning Team reached consensus onthe following sequenced set of strategiesto utilize the river.

C The 50,000-cfs authorized BreauxAct diversion at West Bay in theBirdsfoot Delta should be built assoon as possible.

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C Short studies should be done todetermine the feasibility of using theexisting locks to divert river waterand enriching existing diversionswith sediment. These strategiescould be accomplished by theUSACE under an existing authoritysuch as Section 1135.

C Outfall management plans should bedeveloped for the Davis PondDiversion, possibly under the BreauxAct.

C The most effective small diversionsshould be considered as priority listprojects for the Breaux Act.

Once the USACE completes theMississippi River Sediment, Nutrient,and Freshwater Redistribution FeasibilityStudy, consideration should be given toimmediately implementing the sedimenttrap concept and constructing a delta-building diversion in the MyrtleGrove/Naomi area. Monitoring theMyrtle Grove Diversion would provideinformation to aid in planning the nextdiversion.

There are several considerations involvedin these diversions: oyster lease issues,land rights issues in terms of who ownsmineral rights on the new land, and thepossibility of increased maintenancedredging in the Mississippi River. Timing is another important consideration; one way to create anartificial delta would be to pulse largeamounts of water into the area every fewyears.

Restoration of the barrier islands andriver diversions act synergistically andare critical to the long-term sustainabilityof the estuarine ecosystem.

The only way to prevent the loss of thesouthwestern portion of the BaratariaBasin adjacent to Bayou Lafourche is byimporting massive amounts of sediment,either by dedicated dredging or by aconveyance channel from theMississippi River parallel to BayouLafourche. A feasibility study should beinitiated in the near term. Planning andconstruction phases would be verycomplicated because of the large projectarea and its expected impacts to existinguses such as land-based transportation,navigation, agriculture, drainage systems,harvest of estuarine species, and floodprotection systems. While planningcould begin in the near term, diversionimplementation would likely be in thelong term.


The Regional Planning Team agreed thatthe following delta-building diversionsshould be built in sequence once theMyrtle Grove Diversion is complete:Bastion Bay from Buras, Benny’s Bay,and Quarantine and American Bays.


The conveyance channel from theMississippi River into the Little Lakearea should be built, if feasible. TheBreaux Act delta-splay project and thesiphon outfall management projectsshould be continued from years 21-50.

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During the regional meetings, somediversion scenarios were suggested thatwere not sequenced by the RegionalPlanning Team: major diversions atAmoretta and American Bay. The teampreferred that these strategies beconsidered only after all other strategieshad been built or rejected as infeasible.


Local strategies for Region 2 mappingunits (Fig. 7-6) include restoringhydrology in the Myrtle Grove area byvarious methods. The depth of SouthPass could be limited to that necessaryfor navigation, and more flow should beencouraged to exit through Pass àLoutre. A small freshwater diversionwith outfall management could be builtat Homeplace. Grand Pass could beenriched with sediment from theMississippi River. Whenever theopportunity arises, the hurricaneprotection levee borrow canal that runsfrom near Venice to Empire could befilled to create marsh. Wave absorberscould be placed along the barriershoreline. Either the Empire jetties couldbe removed or a sand bypass systembuilt.

There are several common, coastwidestrategies that could be adopted. Herbivory control could occur in theBaker, Cataouatche/Salvador, desAllemends, Naomi, and Perot/Rigolettesunits. Maintaining shoreline integrity isespecially important around CaminadaBay and Lake Cataouatche. Vegetativeplantings could be considered.

The banks of the Gulf IntracoastalWaterway, the Barataria Bay Waterway,and the Southwest Louisiana Canal

could be stabilized. The pumpsconnected with the Larose-to-GoldenMeadow hurricane protection projectcould be relocated or redirected to placeoutfall into the marsh instead of canals. The function of the Bayou Barataria andBayou L’Ours ridges could bemaintained. The oak ridges on thebarrier islands and shoreline could bereestablished. Dredged material from theBarataria Bay Waterway and fromSouth, Baptiste Collette, Grand and TigerPasses could be used to create marsh. Efforts should be made to beneficiallyuse more material from the MississippiRiver. Material could be dredged fromoffshore to build marsh in Barataria Bay,behind the barrier islands, and inBaptiste Collette, Pass a Loutre and EastBay units. Material from South Passcould be used to create a barrier toprotect marshes along Southwest Pass. For a detailed matrix of local andcommon strategies by mapping unit, see Appendix D.


Background

Region 3 encompasses the Terrebonne,Atchafalaya, and the Teche-VermilionBasins. The region extends from BayouLafourche on the east, to FreshwaterBayou Canal on the west, and north tothe boundary of coastal wetlands asdefined in the Louisiana CoastalWetlands Conservation Plan (La. Dept.of Natural Resources 1997). It covers allor part of the following parishes:Lafourche, Terrebonne, Assumption,Iberville, St. Martin, Iberia, St. Mary,Lafayette, and Vermilion.

St. CharlesWe st Area Je ffe rson

W est A rea

LakeLeary

BaratariaBarr ier Sh ore lines

Cataoua tche /Salvador

Lake W ash./Grande Ecail le

C heniereRonqu ille

De sAlle man ds

S t.Jam esW est A rea

Asum ptionEast A re a

Pe rot,Rig olet tes

W est Po inta la Hache

Plaque mine sArea

Ba ra ta riaBarr ier Is lan ds

Ba ker

Nao miGh eensClove lly

Ea stBa y

F our chon

W estBay

Pa ss aLo utre

Cae rn arvo n

Cub itsGa p

Lake Boeuf

Ba st ia nBay

GrandL iard

Lit t leLake

Am ericanBa y

BretonSou nd

Cam inadaBa y

JeanLaf itte

MyrtleGrove

Bara ta riaBay

JeanLou is Robin

River a uxChene s

Ba ptisteC ollet te

Or leansW est Area

Ascens ionW est A rea

Lafou rcheEast A rea

St. John Th eBaptis t We st Are a

Region 2 M apping Unit B oundaries

10 0 10 20 M iles

N

EW

S

Figure 7-6. R egion 2 m apping units .

102

103

This region covers 1,107,900 acres ofvegetated wetlands. The region containsapproximately 368,550 acres of cypressand bottomland forest. South of theforested wetlands lie 298,300 acres offresh marsh, 92,700 acres of intermediatemarsh, 240,700 acres of brackish marsh,and 140,200 acres of saline marsh.

The Region is divided into three basins(Terrebonne, Atchafalaya, and Teche-Vermilion). Terrebonne Basin is dividedinto four distinct subbasins. The VerretSubbasin is north of Bayous Boeuf andBlack and west of Bayous Terrebonneand Lafourche. It contains forestedwetlands and large lakes. The FieldsSubbasin lies north and east of BayouTerrebonne and north of Bayou Blue,and its wetlands are fresh marshes. ThePenchant Subbasin is south of BayousBoeuf and Black, east of the AtchafalayaRiver and Bay, west of Bayou Du Large,and includes Point au Fer Island. Penchant’s major habitats range fromlarge areas of highly organic freshfloating marshes to more mineralbrackish marshes. The TimbalierSubbasin is south of Bayous Terrebonneand Blue, east of Bayou DuLarge andwest of Bayou Lafourche. Timbalier’smajor habitat types range from organicfresh marshes through saline marshes tobarrier islands. The Atchafalaya Basinincludes Atchafalaya Bay and thenorthern marshes. The Teche-VermilionBasin extends from Point Chevreuil toFreshwater Bayou Canal and includesthe fresh to brackish East and West CoteBlanche Bays, Vermilion Bay, and thesurrounding marshes.

Habitat Objectives

Habitat objectives for the year 2050 werefirst suggested by parish governmentsand representatives of local coastal zoneadvisory committees. Then, as theRegional Planning Team developedstrategies, the habitat objectives wererevised to correlate with the strategies. These revised objectives were approvedby the parishes. Generally, parishgovernments and the public in Region 3would like to maintain present habitats inareas above the Gulf IntracoastalWaterway and revert to past habitats inareas below the Gulf IntracoastalWaterway (Figs. 7-7, 7-8).


Restore Swamps

1. Improve hydrology and drainage inthe Verret Subbasin . Implementation ofa flood protection feature from theUSACE Lower Atchafalaya RiverReevaluation Study would alleviate theproblems associated with chronic andexcessive backwater flooding that islargely due to Atchafalaya Riverinfluence. This feature, known as the“Barrier Plan,” would block waterexchange from south to north at U.S.Highway 90 between Morgan City andHouma. Pumps would be installed to remove excess water from the VerretSubbasin. The effect of this action onfloating marshes in the PenchantSubbasin is uncertain at this time, but thewater should be distributed so as not toimpact these wetlands. Additionalmeasures, such as introducing

106

supplemental water from theAtchafalaya River or the MississippiRiver to the Verret Subbasin duringdrought conditions to address waterquality needs, would be considered. Implementation of this strategy wouldbenefit about 200,000 acres of forestedwetlands and prevent most futureswamp loss. The strategy would protectthe affected communities, industries, andagricultural lands from flooding.

Restore and Sustain Marshes

2. Maximize land building inAtchafalaya Bay . This strategy entailsimplementing a delta management planin Atchafalaya Bay to maximize landbuilding. One feature would be toseparate navigation from the deltadevelopment zone, thereby allowingmore efficient delta growth and reducednavigation channel maintenance. Another element of the strategy wouldbe to train a delta lobe to extend towardFour League Bay to protect nearbymainland marshes from storm surgesand to increase the amount of sedimentavailable for transit into the marshesfrom storms. The delta managementplan would attempt to contain landbuilding sediments in Atchafalaya Bayrather than filling bays to the west. Thisstrategy would maintain the processesthat preserve the mainland wetlands inthe Atchafalaya outlets area. Thisstrategy is anticipated to createsubstantial amounts of marsh by 2050.

3. Lower water levels in upper Penchantmarshes . Wetland stress in the upperPenchant Subbasin is associated withexcessive flooding from the Atchafalaya

River and the Verret Subbasin. Modifying water flow patterns todistribute the fresh water to otherwetland areas, especially the lowerPenchant marshes, would relieve theexcessive flooding. Reducing waterlevels would reduce wetland losses inupper Penchant.

4. Increase transfer of AtchafalayaRiver water to lower Penchant tidalmarshes . Tidal marshes adjacent to FourLeague Bay are strongly influenced byAtchafalaya River flows. These marshesare generally healthy whereas marshesfarther east receive less Atchafalayainfluence and are experiencing higherrates of loss. This strategy wouldimplement measures to distribute moreAtchafalaya flow to the tidal marshes inthe vicinity of Lake Mechant and CaillouLake. Wetland losses are anticipated tobe reduced by the increased flow offresh water and nutrients.

5. Enhance Atchafalaya River waterinfluence to central Terrebonnemarshes (Bayou Dularge to BayouTerrebonne). Implementation of thisstrategy would expand the zone ofbeneficial influence by modifying waterflow patterns to distribute Atchafalayaflow farther east and to adjust the northto south drainage in the area’swatersheds as necessary to maximizewetland benefits. Wetland losses areexpected to be reduced by the increasedflow of fresh water and nutrients.

6. Establish multipurpose control ofHouma Navigation Canal . A lock orgate on the Houma Navigation Canal is afeature in the ongoing Morganza-to-the-

107

Gulf Study that could aid inaccomplishing the strategy for enhancingcentral Terrebonne marshes. The lockand connecting levees could allow moreefficient use of Atchafalaya River waterand sediment flow, aid in maintainingsalinity regimes favorable to areawetlands, and provide hurricaneprotection to residents of TerrebonneParish. More fresh water and less saltwater north of the lock are anticipated toreduce wetland losses.

7. Stabilize banks of navigationchannels for water conveyance . TheAvoca Cutoff Channel, Bayou Chene,the Gulf Intracoastal Waterway (betweenthe Atchafalaya River and BayouLafourche), and the Houma NavigationCanal would function as majorconveyance channels for Atchafalayaflow distribution. Some of the bankshave deteriorated. To perform aconveyance function, the deterioratedchannel banks would need to be rebuiltand stabilized. This strategy actssynergistically with Strategies 3 through6 above (lowering water levels in theupper Penchant marshes, increasing flowto lower Penchant tidal marshes,enhancing Atchafalaya influence tocentral Terrebonne marshes, andestablishing multipurpose control of theHouma Navigation Canal). Takentogether, these five strategies areanticipated to preserve a substantialamount of marsh through 2050.

8. Dedicated delivery of sediment formarsh building by any feasible means . This strategy could be used to rebuildwetlands on a small scale at sites acrossthe region. Sediment could be

transported by pipeline, barge, or truckwhen and where shown to be feasible. For instance, this strategy might be usedto build a substantial amount of marsh inthe lower Timbalier Basin.

9. Build land in upper TimbalierSubbasin by sediment diversion fromthe Mississippi River via a conveyancechannel. The extremely high land loss inthe Timbalier Subbasin is indicative of acollapsed wetland system. Highsubsidence rates, inadequate sedimentsupply, altered hydrology, and increasedtidal exchange rates are largelyresponsible for this condition.

Potentially, the most effective alternativefor rebuilding this wetland system maybe to initiate a new subdelta buildingprocess in the area (Gagliano and VanBeek 1993; Gagliano 1994, 1998;Gagliano and Van Beek 1998). Thissubdelta could be accomplished bydiverting flows from the MississippiRiver, south and east of Donaldsonville,through a conveyance channel parallel tothe developed Bayou Lafourche ridge. The diversion would be about 30,000 cfs,approximately one-third the size of theWax Lake Outlet. A branch of thechannel, carrying about half of the water,would cross Bayou Lafourche belowThibodaux and end in the Bully Camparea. Any project-related navigationfeatures must not impede or interferewith the land building capacity of thechannel. This strategy is anticipated tocreate substantial amounts of land andreduce loss in the Bully Camp andTerrebonne marshes.

108


10. Maintain shoreline integrity andstabilize critical areas of Teche-Vermilion Bay systems including thegulf shorelines . Shoreline erosion is amajor cause of land loss in theTeche-Vermilion Basin. Relative toother coastal basins, interior wetland lossrates are low. By maintaining theshoreline integrity, this strategy isanticipated to preserve a moderateamount of marsh.

11. Maintain shoreline integrity ofmarshes adjacent to Caillou,Terrebonne, and Timbalier Bays . Theirregular shorelines of the bays in theTimbalier Subbasin are retreating rapidly. Interior wetland loss rates are very highin this subbasin. Interior wetlands wouldbenefit from measures that would absorberosive wave energies and would aid inmaintaining favorable hydrologicalconditions. This strategy is anticipatedto preserve a moderate amount of marsh.

Restore Barrier Islands and GulfShorelines

12. Restore and maintain the IsleDernieres and Timbalier barrier islandchains . The Timbalier and IslesDernieres barrier island chains haveseverely eroded. This strategy wouldrestore the island chains to a conditionsuitable for maintaining the integrity ofthe estuarine system. The BarrierShoreline Feasibility Study has evaluatedalternative restoration measures, costs,and benefits of restoring the islandchains. This strategy is anticipated to

create moderate amounts of marsh andbarrier beaches.

Special Concerns and Opportunities: Resolve Vermilion-Cote Blanche Bays

Salinity and Turbidity

The Teche-Vermilion Basin is stronglyinfluenced by the Atchafalaya River.River flow is transported westward intothe basin by the Gulf IntracoastalWaterway, by exchange betweenAtchafalaya Bay and East Cote BlancheBay, and by a diversion from theAtchafalaya into Bayou Teche and theVermilion River. While this influencebenefits wetlands and satisfies someagricultural irrigation needs, there areconcerns about its adverse effects onnavigation and estuarine fisheries.Managing the river’s influence to sustainthe basin’s wetlands is a general strategy. Several measures that address aspects ofthis strategy are being evaluated in theUSACE Lower Atchafalaya RiverReevaluation Study. The followingspecific strategies include other measuresthat address basin needs.

13. Optimize Gulf IntracoastalWaterway flows into marshes andminimize direct flow into bays . Withthis strategy, Gulf Intracoastal Waterwayflows would be routed through wetlandareas before draining into the bays. Sediments and nutrients would beretained in the wetlands, and bay watertemperatures would be increased. Thisstrategy is anticipated to preserve amoderate amount of marsh.

109

14. Maintain Vermilion, East and WestCote Blanche Bays as brackish . Whilethis strategy could be viewed as anobjective, the sensitivity surrounding thisissue required the statement be made astrategy. No specific measures havebeen identified to implement thisstrategy. The main expectation is toachieve the objective when planningother measures in the region that couldaffect bay salinities. Benefits for thisstrategy have not been estimated.

15. Reduce sedimentation in bays . Measures identified to implementStrategies 2, 13, and 16 (maximizing landbuilding in Atchafalaya Bay, optimizingGulf Intracoastal Waterway flows intomarshes and minimizing direct flow intobays, and creating an artificial reefcomplex) would aid in accomplishingthis strategy. Other measures to reduceAtchafalaya River influence to thesebays are being evaluated in the USACELower Atchafalaya River ReevaluationStudy. Benefits for this strategy have notbeen estimated.

16. Create an artificial reef complexincluding one from Point Chevreuiltoward Marsh Island . An artificial reefwould be constructed along thealignment of the natural reef that wasmined earlier this century. Expectationsare that the reef would restore somesemblance of the former hydrology inEast Cote Blanche Bay and adjacentwetlands. The reef would also enhancefisheries through reduction of turbidityand bay infilling. This strategy has nomeasurable marsh benefits.



This category includes strategies thatrequire implementation prior to otherrestoration strategies because adversehydrologic impacts could result fromreversing the order. The urgency offlood protection must also beconsidered.

Improved hydrology and drainage in theVerret Subbasin in the near term wouldbe required before Atchafalaya Riverresources could be optimized forwetland restoration in the Atchafalaya orTerrebonne Basins in the intermediateterm.

In the Terrebonne wetlands, dedicateddelivery of sediment would be animportant strategy to maintainabandoned distributary ridges such asthe natural levees of Bayous Lafourche,Pointe Au Chien, and Terrebonne. Furthermore, this strategy could be usedto enhance flood protection by buildingwetlands adjacent to levees. Thisstrategy could be implementedindependently of, or concurrently with,other restoration or flood protectionmeasures.

The potentially most effective way toprevent loss in the Timbalier Subbasin isby importing massive amounts ofsediment to create a new subdelta. Afeasibility study should be initiated todetermine if a conveyance channelparallel to Bayou Lafourche is the mosteffective strategy. Planning andconstruction phases would be verycomplicated because of the large project

110

area and its expected impacts to existinguses such as land-based transportation,navigation, agriculture, drainage systems,harvest of estuarine species, and floodprotection systems. A network of floodprotection systems would be necessaryand would extend from the MississippiRiver to the lower reaches of BayousLafourche, Terrebonne, and Pointe AuChien. Some flood protection systemsare in place and others are presentlybeing planned. While planning couldbegin in the near term, diversionimplementation would likely be in theintermediate to long term.

Barrier island restoration in theTerrebonne Basin and protection of theRainey Marsh gulf shoreline could beimplemented in the near term, before theislands and shoreline deteriorate further. These restoration measures could beimplemented independently of otherstrategies and would enhance theeffectiveness of other restorationstrategies such as maintaining shorelineintegrity and building a new delta lobe inthe Timbalier Subbasin.

The strategies to maintain bay shorelineintegrity in the Teche-Vermilion andTerrebonne Basins could beimplemented independently of otherstrategies. Shoreline integritymaintenance is not limited to one pointin time in a 50-year period, butmaintenance as needed over the entireperiod. Thus, its logical place insequencing is at the beginning of the50-year period. These strategies canenhance other strategies or be enhancedby other strategies. For example, thededicated delivery of sediment strategycould be a construction alternative for

shoreline protection. The shorelinemaintenance strategies would help toachieve the strategy to reducesedimentation in Cote Blanche andVermilion Bays.

The four strategies developed to addressconcerns over Atchafalaya Riverinfluence in the Teche-Vermilion Basinshould be implemented in the near term,as river influence is expected to increaseover time. These strategies would notconflict with other restoration strategies. Maximizing land building in AtchafalayaBay in the intermediate term could beplanned and implemented to facilitatethe strategic objectives of sedimentreduction and maintenance of a brackishsalinity regime in the bays of the Teche-Vermilion Basin.


This category includes strategies thatrequire prior implementation ofnear-term strategies that would protectother wetlands and developed areas fromincreased water levels.

The first strategy in this category is tomaximize land building in AtchafalayaBasin, primarily in Atchafalaya Bay. Accomplishment of this strategy wouldlikely result in higher water levels inTerrebonne wetlands, thereby increasingriver influence in that area.

Several regional strategies are interrelatedhydrologically and involve optimizingAtchafalaya River influence to westernand central Terrebonne wetlands. Bankstabilization along waterways would benecessary to improve their efficiencyconveying Atchafalaya River water to

111

central Terrebonne. Once in the centralmarshes, the water could be optimallydistributed to wetlands in the vicinity ofthe Houma Navigation Canal, LakeBoudreaux, and lower Bayou La Cache. Establishing multipurpose control of theHouma Navigation Canal would greatlyfacilitate the management potential ofriver influence in the canal area.

Bank stabilization is also a precursor tolowering water levels between theAtchafalaya River and the centralTerrebonne wetlands. Water levels canbe lowered in the weakly tidal, freshupper watershed area by distributingexcess water across the ridges to thetidal, brackish lower watershed area. These strategies incorporate majorhydrologic components of a watershedplan for the western and centralTerrebonne wetlands.

Long-Term (16-50 years)

If determined to be feasible, the BayouLafourche conveyance channel would bebuilt in the intermediate or long term.


There are only three local strategies inRegion 3. In all mapping units (Fig. 7-9)with hurricane or protection levees, thelocal strategy is to protect againsthurricanes and flooding by maintainingan apron of marshes outside the levees. In the Wax Lake Wetlands unit, the localstrategy is to maintain the Wax Lakedistributaries, for example Hog Bayou. Another Breaux Act project, the JawsTerracing Project, should be maintainedthrough the year 2050.

There are several common, coastwidestrategies that could be adopted inRegion 3. Banks of navigation channelssuch as the Houma Navigation Canaland the Gulf Intracoastal Waterwaycould be stabilized in all mapping unitsthat contain such channels (St. LouisCanal, Terrebonne, Pelto Marshes, Fieldsand Devil’s Swamps, HNC Wetlands,Avoca, Gulf Intracoastal Waterway,Penchant, Mechant de Cade, Wax LakeWetlands, North Wax Lake Wetlands,Atchafalaya Marshes, Rainey Marsh,Cote Blanche Wetlands, and VermilionBay Marsh). In addition, materialdredged during maintenance of thesenavigation channels could be usedbeneficially in nearly every unit.

Bay, lake, and gulf shoreline integritycould be protected wherever these areeroding, and critical areas could bestabilized in an area that includes overtwo-thirds of the mapping units.

Establishing and protecting ridgefunctions are important in all units withsuch ridges (North and South BullyCamp, St. Louis Canal, Montegut,Terrebonne Marshes, Boudreaux,Caillou, Avoca, Penchant, Mechant deCade, Rainey Marsh, Big Woods, CoteBlanche Wetlands, and Vermilion BayMarsh). In the Verret Wetlands and Fields Swamps, a strategy of routingpump outfall through the wetlands couldbe adopted. For a detailed list of localand common strategies by mapping unit,see Appendix E.

Reg ion 3 Ma pp in g U nit Bou nda ries

10 0 10 20 M iles

N

EW

S

Figur e 7-9. R egion 3 mapping units .

AvocaSavoie

Montegut

Penchant

BigWoods

B ou d

reau

x

MarshIsland

Pointau Fer

RaineyMarsh

Devil's Swamp

PeltoMarshes

PigeonSwamps

St. MaryArea

VermilionBay

FourleagueBay

Mechant/de Cade

VerretWetlands

Chacahoula SwampsVermilionBay Marsh

AssumptionWest Area

AtchafalayaSubdelta

E. CoteBlanche

Bay

Isles DernieresShorelines

Black Bayou WetlandsLafourche West Area

St. Louis Canal

TerrebonneMarshes

South

Bul

lyCa

m p M

ars h

North Houma ShipCanal Wetlands

Fields Swamp

North BullyCamp Marsh

Terrebonne Area

Timbalier IslandShorelines

Caillou Marshes

GIWW

Atcha fa laya

Marshes

Wax LakeWetlands

Wax LakeOutlet Subdelta

NorthWax LakeWetlands

Cote BlancheWetlands

West CoteBlanche Bay

St. MaryArea

112

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Background

Region 4 extends from the western bankof the Freshwater Bayou Canalwestward to the Louisiana/Texas borderin Sabine Lake, and from the marshareas just north of the Gulf IntracoastalWaterway south to the Gulf of Mexicoin Vermilion, Cameron, and CalcasieuParishes. Region 4 comprisesapproximately 1,307,000 acres of marsh,open water, and chenier habitats. Marshtypes and their associated acreage acrossthe region are: 354,600 acres (45%) offresh marsh, 171,700 acres (23%) ofintermediate marsh, 198,600 acres (27%)of brackish marsh, and 33,200 acres (5%)of saline marsh.

Region 4 consists of two basins: theMermentau and the Calcasieu-Sabine. The Mermentau Basin extends fromFreshwater Bayou Canal westward toHighway 27 and is divided into twosubbasins along an east-west line in thevicinity of the Pecan Island and GrandChenier ridges. North of this line is theLakes Subbasin, whose natural drainagehas been interrupted by many canals andthe placement of several water controlstructures. The subbasin now functionsalmost like a large freshwaterimpoundment. Areas immediately to thenorth of the region are used primarily forrice and crawfish farming. TheMermentau River, which runs diagonally(NE to SW) across the basin, suppliesfresh water to the basin. Two large lakes,Grand and White Lakes, are located inthe Lakes Subbasin. The ChenierSubbasin lies between the Gulf of

Mexico and the Pecan Island/GrandChenier ridge complex. Drainage canoccur eastward to Freshwater BayouCanal, southward to the Gulf of Mexico,and westward to the Mermentau Riverand Ship Channel.

The Calcasieu-Sabine Basin is a shallowcoastal wetland system with freshwaterinput at the north end and a north-southcirculation pattern through Calcasieu andSabine Lakes and some east-west watermovement which occurs through theGulf Intracoastal Waterway and interiormarsh canals (e.g., North Line Canal andSouth Canal on Sabine National WildlifeRefuge). Both lakes are connected toimportant shipping corridors and areused for recreational purposes as well. As in the Mermentau Basin, managedwetlands are a significant feature of thearea, with structures in the Cameron-Creole Watershed, the Sabine NationalWildlife Refuge, and on privately ownedlands.

Habitat Objectives

The Region 4 Habitat Objectives for theyear 2050 were developed by theObjectives Development Teamconsisting of parish governmentrepresentatives and the local coastaladvisory committees of Vermilion,Cameron, and Calcasieu Parishes. Generally, the habitat objectives mapproduced by the ObjectivesDevelopment Team reflected a reductionof the salinities of the marsh habitats inthe western and southern areas ofRegion 4 (Figs. 7-10, 7-11). The LakesSubbasin is presently composed of freshto intermediate marsh. The habitat

116

objective for this area is to convert mostof the area to fresh marsh. The objectivefor the Chenier Subbasin is to convertthe existing saline and brackish marshesto brackish and intermediate marshes bythe year 2050. The objective for theCalcasieu-Sabine Basin is to createfresher conditions by the year 2050.


Because of the socioeconomic demandsand opportunities which exist in thisregion, it is not realistic to return to“natural” conditions by taking actionssuch as restoring Calcasieu Pass orSabine Pass to their pre-1900 conditions,filling in the Gulf Intracoastal Waterway,or filling in the myriad of smaller canals. In a manner which accommodates,better uses, and improves existinginfrastructure, the goals of the regionalstrategies for Region 4 are: (1) toeliminate adverse hydrologic conditions,including elevated water levels andextreme salinity spikes, and (2) toreestablish or maintain the integrity ofmajor natural landforms.

Restore and Sustain Wetlands

1. Operate locks to evacuate excesswater from the Lakes Subbasin . Bylowering water levels in a timely manner,inundation-related plant stresses couldbe relieved and lake shoreline erosioncould be reduced. In recent years, thisstrategy has been partially implementedwith some success. Continued andadditional benefits could be derived byconsistently operating structures 24hours per day at all five control points

(Calcasieu Lock, Leland Bowman Lock,Schooner Bayou Control Structure,Catfish Point Control Structure, andFreshwater Bayou Lock). Operationshould strive to reduce the duration ofmarsh inundation during and afterperiods of high rainfall, achieve waterelevations which are conducive to marshvigor and health inside the lock system,and allow free outflow of water wheninside water levels exceed target waterlevels and a drainage differential exists. This strategy is expected to preserve amoderate amount of marsh by 2050.

2. Operate existing Calcasieu Lockspecifically to evacuate excess water,after building a new lock on a parallelchannel specifically for navigation. TheCalcasieu Lock site is thought to be thebest of the existing sites for theevacuation of excess water. The newlock would allow water evacuation andnavigation to function independently andwithout conflict. Operation goals wouldbe as stated above. This strategy isanticipated to preserve a moderateamount of marsh by 2050 by loweringwater levels.

3. Manage watershed to reduce rapidinflows into the Lakes Subbasin . Drainage improvements in theMermentau River watershed allow water,particularly during and after high rainfallevents, to reach the Lakes Subbasin veryquickly, causing elevated water levels. Without impeding drainage fromexisting developed or agricultural lands,this strategy would slow the flow ofwater, perhaps through incentiveprograms, catch basins, or stream

*These strategies apply whether the TTWP is implemented or not, but are an absolute must if the TTWP isimplemented. 117

restoration. This strategy is expected topreserve a moderate amount of marsh by2050.

4. Move water from north to southacross Highway 82 with associateddrainage improvements south ofHighway 82 . This strategy is two-fold:to evacuate excess water from the LakesSubbasin, and to provide freshwater tothe Chenier Subbasin. Water could bemoved from north to south with a seriesof gravity drainage structures and/orpumps along Highway 82. Aprerequisite for such structures or pumpswould be to improve drainage south ofHighway 82, perhaps establishing a flow-through system. This strategy isanticipated to preserve a major amountof marsh by 2050.

5. Restore the connection of theoriginal Mermentau River to the Gulf ofMexico and constrict the width anddepth of the Mermentau Ship Channelto its authorized dimensions . Thepurpose of this strategy is also two-fold:to allow better drainage of wetlandslocated along the lower 5 to 7 miles ofthe original Mermentau River, and toreduce the intrusion of salt water up theMermentau Ship Channel. This strategyis anticipated to preserve a minoramount of marsh by 2050.

6. Dedicated dredging of sediment forwetland creation. This strategy consistsof dredging material from channels orlakes to create marsh in rapidly erodingunits such as Lacassine; Cameron CreoleWatershed; Sweet and Willow Lakes;Big, Brown, and Black Lakes; and SouthPecan Island. This strategy is projected

to create a moderate amount of marsh.

7. Maintain Atchafalaya River waterand sediment inflow through the GulfIntracoastal Waterway . Presently,marshes in the Mermentau Basin seemto be deriving benefit from the flow ofAtchafalaya River water and sedimentthrough the Gulf Intracoastal Waterway. The purpose of this strategy is todiscourage any curtailment of such flowthrough the Gulf Intracoastal Waterway.

Salinity Control in the Calcasieu Basin

8. Salinity control of the Calcasieu ShipChannel between the Gulf of Mexicoand Calcasieu Lake . Salinity controlcould be established by installing a gate,lock, or other saltwater barrier. Theprimary goal of this strategy is to reducepeak salinities, probably limited to aseasonal basis. During nonpeaksalinities, navigation would beunaffected. Should such control beestablished, perhaps the need formaintenance and/or intensive operationof lakeside control structures could bereduced in the future. This strategy isexpected to preserve a major amount ofmarsh by 2050.

Salinity Control of the Sabine Basin *

9. Maintain Sabine River inflow . Theprimary focus of this strategy is todiscourage implementation of the Trans-Texas Water Plan (TTWP) via proactiveparticipation, including projection offuture conditions, education regardingadverse effects, direct opposition toTTWP if appropriate, and development

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of measures to mitigate the TTWP. 10. Salinity control at Sabine Pass . Salinity control could be established byinstalling a gate, lock, or other saltwaterbarrier in Sabine Pass. The primary goalof this strategy is to reduce peaksalinities, probably limited to a seasonalbasis. During nonpeak salinities,navigation would be unaffected. Thisstrategy is expected to preserve asubstantial amount of marsh by 2050 byreducing salinities.

11. Salinity reduction of Sabine Lake atthe Causeway . Salinity reduction couldbe accomplished by a sill type structurethat would allow small to medium boatnavigation. Large boat navigation(barges, ships, etc.) through the Sabine-Neches Waterway would be unaffected. This strategy is anticipated to preserve amoderate amount of marsh by 2050.

12. Salinity control on the eastshoreline of Sabine Lake . The primarygoal of this strategy is to reduce thepenetration of peak salinities into theinterior marshes. This strategy isexpected to preserve a major amount ofmarsh by 2050.

13. Salinity Control in the GulfIntracoastal Waterway east of SabineRiver. The primary goal of this strategyis to reduce the flow of high salinitywater eastward from Sabine River,through the Gulf Intracoastal Waterway,and into the interior marshes. Thisstrategy is anticipated to preserve amoderate amount of marsh by 2050.


14. Stabilize Grand Lake and WhiteLake shorelines . These two very largelakes are experiencing significantshoreline erosion. In many areas thehistoric shoreline rim is completely lost,exposing interior organic soil marshes tohigh wave energy. Shorelinestabilization should address the ongoingdirect loss as well as increasing rates ofloss for interior marshes which otherwisewould be exposed to wave energy. Thisstrategy is expected to preserve a majoramount of marsh by 2050.

15. Stabilize Gulf of Mexico shoreline inthe vicinity of Rockefeller Refuge . Witha shoreline retreat rate of 35 feet peryear, shoreline stabilization is necessaryto address the direct loss of wetlands.This strategy is anticipated to preserve amajor amount of marsh.

16. Stabilize Gulf of Mexico shorelinefrom Calcasieu Pass to Johnson’sBayou. In addition to the long-termthreat to interior wetlands posed bypotential shoreline breaches andsaltwater intrusion, there is an immediatethreat to sections of Highway 82 whichwould be addressed with this strategy ofholding the shoreline in its currentposition. This strategy is expected topreserve a moderate amount of marsh by2050.

17. Maintain Atchafalaya Rivermudstream in the Gulf of Mexico . Presently, certain reaches of the GulfMexico shoreline in Region 4 areprograding because of the Atchafalaya

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River mudstream (see Fig. 3-5b). Thepurpose of this strategy is to discourageany curtailment of such a stream in theGulf of Mexico.

18. Restore long-shore sediment flowacross the mouth of Calcasieu Pass. Jetties installed for reducingsedimentation within the Calcasieu ShipChannel have interrupted long-shoresediment transport along the Gulf ofMexico shoreline. Sediment bypassmechanisms would help reduceshoreline retreat west of the CalcasieuShip Channel, and could beimplemented as part of Strategy 16above. This strategy is anticipated topreserve a minor amount of marsh by2050.

19. Restore long-shore sediment flowacross the mouth of Mermentau ShipChannel. Jetties installed for thepurpose of reducing sedimentationwithin the Mermentau Ship Channelhave interrupted long-shore sedimenttransport along the Gulf of Mexicoshoreline. Sediment bypass mechanismswould help reduce shoreline retreat westof the Mermentau Ship Channel. Thisstrategy is likely to preserve a minoramount of marsh by 2050.

20. Prevent the coalescence of GrandLake and White Lake . Individually,Grand Lake and White Lake arepresently very large and are experiencingsignificant shoreline erosion. If allowedto coalesce, the fetch and probablyerosion rates will increase tremendously.Additionally, if the lakes coalesce, watercirculation patterns throughout the LakesSubbasin will likely be altered and wind-induced water stacking will likely

exacerbate marsh inundation, leading toincreased interior marsh loss. Thisstrategy is expected to preserve a majoramount of marsh by 2050.

21. Prevent the coalescence of GrandLake and the Gulf IntracoastalWaterway. If Grand Lake and the GulfIntracoastal Waterway are allowed tocoalesce, the north bank of the waterwaywill be exposed to the fetch of GrandLake and water circulation patternsthroughout the Lakes Subbasin willlikely be altered. This strategy isanticipated to preserve a minor amountof marsh by 2050.


Near Term (1 to 5 years)

There are four regional strategies thatsimply call for using existinginfrastructure or discouraging futurehuman activities that may adverselyaffect wetlands. Implementation ofthese strategies by the appropriateentities should be pursued immediately.They include: operating locks toevacuate excess water from the LakesSubbasin, maintaining Atchafalayasediment inflow through the GulfIntracoastal Waterway, maintainingSabine River inflow, and maintainingAtchafalaya water and sediment streamin the Gulf of Mexico. Although notidentified as a regional strategy, initiationof the Hydrologic Investigation of theChenier Plain, funded by the BreauxAct, should proceed immediately so thatthe resulting information can be used todesign specific projects called for inother strategies.

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Additional strategies recommended forthe near term include those for whichthere is a considerable body ofknowledge; existing, “on-the-ground”projects which can be used to aid in thedesign of specific projects; and thosewhich address an immediate threat towetlands or critical infrastructure. Thesestrategies include: moving water fromnorth to south across Highway 82 withassociated drainage improvements southof Highway 82, salinity control on theeast shoreline of Sabine Lake, stabilizingGrand Lake and White Lake shorelines,stabilizing the Gulf of Mexico shorelinein the vicinity of Rockefeller Refuge,stabilizing the Gulf of Mexico Shorelinefrom Calcasieu Pass to Johnson’sBayou, restoring long-shore sedimentflow across the mouths of CalcasieuPass and the Mermentau Ship Channel,preventing the coalescence of GrandLake and White Lake, preventing thecoalescence of Grand Lake and the GulfIntracoastal Waterway, and dedicateddredging for wetland creation.

Intermediate Term (6 to 15 years)

Strategies recommended forimplementation in the intermediate termare those for which the existing body ofknowledge is insufficient to confirm themerit, and/or determine the feasibilityand optimal design. All of thesestrategies would benefit from theinformation gathered via the HydrologicInvestigation of the Chenier Plain. Furthermore, these strategies wouldrequire close coordination withinterested user groups. This group ofstrategies includes: operating the existingCalcasieu Lock specifically to evacuate

excess water after building a newnavigation lock on a parallel channel,managing the watershed to reduce rapidinflows into the Lakes Subbasin,restoring the connection of the originalMermentau River to the Gulf of Mexicoand constricting the width and depth ofthe Mermentau Ship Channel to itsauthorized dimensions; and salinityreduction of Sabine Lake at theCauseway.


Because of their magnitude, the need forfeasibility analyses, and the potentialeffect on navigation and other uses, thefollowing strategies are recommendedfor implementation in the long term:salinity control of the Calcasieu ShipChannel between the Gulf of Mexicoand Calcasieu Lake, salinity control atSabine Pass, and salinity control in theGulf Intracoastal Waterway east of theSabine River. If salinity control atSabine Pass is feasible and receivesfunding, salinity control on the GulfIntracoastal Waterway would probablynot be necessary.


Hydrologic restoration is a local strategyrecommended for nearly all of theRegion 4 mapping units (Fig. 7-12). Local hydrologic restoration strategiesinvolve the use of dams or water controlstructures to restore the alteredhydrology in the various units.

These strategies would reduce saltwaterintrusion or water levels and/or restoretidal flow and fisheries access to the

Amoco

Cameron

Big Burn

Big L ake

GumCove

MudLak e

BigMarsh

Hog Bayou

Lac assine

Oak Grove

West Cove

Blac kLake

BrownLake

GrandLake

White Lak e

BlackBayou

PerryRidge

Rockefeller

ClearMarais

L itt lePecan

MiddleM arsh

SecondBayou

WillowBayou

Loc ustIsland

North Grand Lake

S. WhiteLake

CalcasieuLake

LowerMud Lake

SabinePool #3

GrandLake East

S. PecanIsland

ChoupiqueIs land

S. E. Sabine

Sweet/W illowLakes

GrandChenier Ridge

Johnson'sBayou Ridge

S. W.Gum Cove

W. BlackLake

Martin Beac hShip Canal Shore

East Johnson'sBayou

HackberryRidge

HogIslandGully

SabineLake

WestJohnson's Bayou

Sabine LakeRidges

N. W hiteLake

Litt lePrairie

Cameron-Prairie

Cameron-Creole

Watershed

Grand/WhiteLake Land

Bridge

Regio n 4 Ma pp ing U nit Boun dar ies

10 0 10 20 M ile s

N

EW

S

Figure 7-12 . R egion 4 m app ing units .

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marshes. Freshwater introductionstrategies are found in Little Pecan,South Pecan Island and Hog Bayou,where there is a need for, and a sourceof, freshwater to counteract the effects ofincreased saltwater intrusion (Fig. 7-11). Maintaining drainage infrastructure is alocal strategy for the Cameron unit. Maintaining “perched” marshes, wherefresher marshes have formed on dredgedmaterial sites, is a strategy unique to theChoupique Island unit. Generalshoreline stabilization is a widespreadcommon strategy for nearly everyRegion 4 mapping unit.

Terracing and vegetative plantings arecommon strategies that can be applied toany of the 50 Region 4 mapping unitsthat contain substantial areas of shallowopen water. This technique has alreadybeen applied on two wildlife refuges. The soil conditions in Region 4 aregenerally more conducive to terracingwhen compared to other regions. Maintain ridge function is anothercommon strategy that is applicable tothose mapping units with existing ridgesor cheniers. Vegetative planting, apartfrom terracing, is a common strategywhich can be applied to any mappingunits which are composed of shallowwater with little wave action.

Dedicated dredging has beenrecommended for the Grand and WhiteLakes Land Bridge and South PecanIsland mapping units, but it can beapplied to any mapping unit in Region 4which has critical shallow open waterareas which are in danger of opening intolarger lake or bay systems.

Beneficial use of dredged material is astrategy which can be applied to anyRegion 4 mapping unit which is adjacentto a major navigation channel such asthe Calcasieu or Sabine Ship Channels,or Freshwater Bayou Canal. The GulfIntracoastal Waterway crosses the entireregion and is found in 20 of the region’s50 mapping units. Bank stabilizationalong the Gulf Intracoastal Waterway isa necessary common strategy.

Herbivory control is a common strategythat can be applied to problem areas inRegion 4, including the Middle Marsh,East Johnson’s Bayou, and SecondBayou mapping units. For a detailedmatrix of local and common strategiesby mapping unit, see Appendix F.

Costs and Benefits ofRegional Ecosystem

Strategies

Region 1 Benefits

Implementing the regional ecosystemstrategies would achieve the overarchinggoal of Coast 2050: sustaining a coastalecosystem that supports and protects theeconomy and culture of southernLouisiana and contributes greatly to theeconomy and well-being of the nation. Implementing all of the regionalstrategies proposed for the LakePontchartrain Basin is estimated toprevent approximately 74% of the marshloss across the entire region by 2050,thereby saving 33,500 acres of marsh. The benefits of local and commonstrategies have not been estimated, but itcan be assumed that implementation ofsome of these strategies could reduceloss slightly more.

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Implementation of the regional strategieswould have restored the highestpracticable acreage, given the constraintsplaced on Mississippi River diversionsby local interests. Vertical accretion inthis basin would come mainly fromsmall river diversions that providenutrients. The marshes that would bepreserved would have the functions andvalues of natural ecosystems. Many ofthe strategies will provide multiple-usebenefits such as providing marsh toprotect the New Orleans metropolitanarea.

A good estuarine gradient will beachieved in Region 1, and there will beextensive habitat diversity. There will beessentially no barriers to exchange ofenergy and materials between thewetlands and the estuary.

Region 2 Benefits

Implementing the regional strategieswould achieve the overarching goal ofCoast 2050: sustaining a coastalecosystem that supports and protects theeconomy and culture of southernLouisiana and contributes greatly to theeconomy and well-being of the nation. By 2050, it is projected that there wouldbe 189,900 additional acres of marshcompared to what would exist withoutthe strategies. Not only would no netloss be achieved in the region, but therewould be a 51% gain by the year 2050. The highest practicable acreage wouldhave been restored.

The marshes created and preserved bythese strategies would have the functionsand values of the natural ecosystem.

Several of the strategies such as theBayou Lafourche conveyance channeland river diversions in PlaqueminesParish, if feasible, would providemultiple-use benefits. The hurricaneprotection levees parallel to BayouLafourche and in Plaquemines Parishwill be protected by adjacent marsh. Louisiana Highway 1 will have a strip ofprotective marsh to its east.

The ecosystem objective of verticalaccumulation would be achieved byusing the Mississippi River nutrients andsediments to increase vegetative plantgrowth and to create and preserve marsh. Extensive use of Mississippi River waterwould accentuate vertical accumulationbut reduce the estuarine gradient bylimiting future areas of saline marsh. This tradeoff is necessary to makeopportunistic use of the nutrients andsediments of this river. Sequentialoperation of future diversions mightreduce the adverse salinity impacts. Theregion would still have habitat diversityfrom bottomland hardwoods andswamps in the upper end throughextensive marshes to barrier islands andshorelines near the gulf. There would beextensive exchange of energy andmaterials between the wetlands and theestuary.

Because of deteriorating marshconditions, fisheries will diminishdramatically well before 2050 if noaction is taken. While the proposedstrategies may produce short-termadverse impacts to fisheries, suchstrategies are needed to prevent long-term significant decline or collapse infisheries production. Short-term

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fisheries impacts would need to beaddressed to render river-orientedstrategies acceptable.

Region 3 Benefits

Implementing the regional strategieswould achieve the overarching goal ofCoast 2050: sustaining a coastalecosystem that supports and protects theeconomy and culture of southernLouisiana and contributes greatly to theeconomy and well-being of the nation. By 2050, there would be 119,600additional acres of marsh and 46,700additional acres of swamp compared towhat would exist without the strategies. No net loss would be achieved inswamps and 91% of the predicted marshloss would have prevented. The highestpracticable acreage would have beenrestored.

The marshes created and preserved bythese strategies would have the functionsand values of the natural ecosystem. Several of the strategies such as theBayou Lafourche conveyance channelwould provide multiple-use benefits tocommunities and infrastructure. Theecosystem objective of verticalaccumulation would be achieved byusing water and sediment from theAtchafalaya and Mississippi Rivers andby protecting the self-sustainingwetlands in the Teche-Vermilion systemfrom bay and lake shoreline erosion.

The extensive use of Atchafalaya andMississippi River waters wouldaccentuate vertical accumulation butreduce the estuarine gradient by limitingfuture areas of saline marsh. This

tradeoff is necessary to makeopportunistic use of the nutrients andsediments of these two rivers. Theregion would still have extensive habitatdiversity from bottomland hardwoodsand swamps in the upper end throughextensive marshes to barrier islands nearthe gulf. There would be extensiveexchange of energy and materialsbetween the wetlands and the estuary. There is a possibility that this exchangecould have adverse impacts on floatingmarsh.

Region 4 Benefits

Implementing the regional strategieswould achieve the overarching goal ofCoast 2050: sustaining a coastalecosystem that supports and protects theeconomy and culture of southernLouisiana and contributes greatly to theeconomy and well-being of the nation.

The major strategies in the MermentauBasin involve removing water from theLakes Subbasin. These strategies areprojected to reduce future loss by 57% inthis basin, resulting in an additional34,730 acres being present in 2050 whencompared to no additional restorationefforts. In the Calcasieu-Sabine Basin,major strategies involve controllingsalinity. If the TTWP is notimplemented, and salinity control isimplemented along the lake shore in thenear term and at Sabine Pass in the longterm, the regional strategies are projectedto reduce the Calcasieu-Sabine Basinloss by 61%, resulting in an additional24,810 acres being present in 2050. Ifthe TTWP is implemented, regionalstrategies are projected to reduce marsh

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loss by only 31% in the Calcasieu-Sabine Basin.

In this region, there is no significantsource of sediments. Thus, verticalaccumulation must be achievedpredominately by the organic productionwhich could take place if excess watercan be removed and salinity can becontrolled. This salinity control wouldallow simulation of the historic estuarinegradient and maintain large areas as freshand intermediate marsh. While theprojected exchange and interface inRegion 4 may be less than in otherregions, a healthy ecosystem whichmore closely resembles the historiccondition and produces the highestpracticable acreage would likely exist ifthese strategies were implemented. Water management actions should striveto allow, to the greatest extentpracticable but without negative impactsto the ecosystem, detrital exchange andaquatic organism movement so as tooptimize functions and values. Theregional strategies will provide multiple-use benefits by preserving a band ofmarsh adjacent to highways anddeveloped areas.

Costs

The costs of the regional ecosystemstrategies have been roughly estimated. The total dollar figure is generally thepresent value of construction costs. Maintenance costs are included wheremaintaining the landform is a vital part ofthe strategy. Monitoring costs are notincluded. No estimates have been madefor local or common strategies. Theapproximate cost of implementing all the

regional ecosystem strategies across theentire coast is approximately $14 billion.

Benefits of RegionalStrategies

to Communities at Risk

As described earlier (Chapter 6), the veryexistence of many small coastalcommunities is threatened by marshloss. The regional strategies describedabove would significantly improve thefuture of these communities.

South Lafourche Corridor

If the strategies in Region 2 and Region 3are implemented, the South LafourcheCorridor is expected to have more marshadjacent to it in 2050 than it does today. Land can be built immediately withdredged material to protect La. Highway1. Wave absorbers and preservation ofthe land bridge will reduce loss to theeast of the corridor. Then, once theBayou Lafourche Conveyance Channelis constructed, it will build deltas thatwrap around both sides of the corridor. The regional strategies are anticipated toallow the preservation of this vitalcorridor.

New Orleans Metropolitan Area

If the strategies in Regions 1 and 2 areimplemented, the New Orleansmetropolitan area will have more marshadjacent to it than it does today. Ifnothing is done, 25% of the marsheswest of the area will be gone by 2050. Ifthe strategies are implemented, it isestimated that there will be no net loss in

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the La Branche area. There are presentlyextensive marshes stretching east fromthe metropolitan area to ChandeleurSound. If no more marshes are restored,41 square miles of these marshes will begone by 2050. If the Region 1 strategiesare implemented, it is anticipated thatonly 20 square miles of marsh will havebeen lost by 2050. Marshes to the southof the area also offer protection. Ifnothing is done, 19 square miles justsouth of the metropolitan area will belost by 2050. If the Region 2 strategiesare implemented, only nine square milesare expected to be lost. These regionalstrategies will provide significantprotection to the New Orleansmetropolitan area by preserving a marshbuffer that should reduce hurricanedamage.

Yscloskey

The regional strategies are expected toprevent some loss of marsh to the northand east of the community— only 21square miles will be lost instead of 34.Stabilizing the north bank of MRGO andthe shoreline of Lake Borgne shouldprovide most of these benefits. Thereare essentially no regional strategies forthe marshes to the south, so there wouldstill be nearly ten square miles lost. Common strategies such as beneficialuse of dredged material could, however,restore marshes in this area and helpmaintain Yscloskey as a viablecommunity.

Cocodrie

The regional strategies for Region 3 areanticipated to preserve significant

amounts of marsh in the vicinity ofCocodrie. Instead of 55% of themarshes to the north being gone by2050, only 16% would be lost. To theeast, instead of 64% of the marshesbecoming open water, only 32% wouldbe lost. The strategies do little for themarshes to the west, so there would stillbe about 35% lost. The strategies thatprovide most of the benefits are movingAtchafalaya River water to the lowertidal marshes, stabilizing the banks of theHouma Navigation Canal, and building acontrol structure in the canal. Once theBayou Lafourche Conveyance Channelis built, it will provide significant benefitsto the marshes to the east of Cocodrie. These strategies will contribute thecontinued existence of Cocodrie.

Holly Beach/Constance Beach

Regional strategies in Region 4 areexpected to help reduce marsh loss northof these communities and will helpprotect La. Highway 82. Stabilizing thegulf shoreline and restoring longshoresediment flow across the mouth ofCalcasieu Pass will protect thecommunities from direct attack by thegulf. These strategies should helppreserve these beach communities.

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CHAPTER 8

INSTITUTIONAL ISSUES

A priority in the Coast 2050 planningprocess has been to address institutionalissues, which are issues arising fromactions such as government funding andregulation. There are literally dozens ifnot hundreds of Federal, State, and localprograms that can have an impact onwetlands. In the past, the efforts made toalign these programs toward commongoals have not been comprehensive, norhave they been uniformly effective. Directing government decisions to acommon end is an essential step ineffective restoration.

Breaux Act Coordination

Consistency among certain uses ofcoastal Louisiana’s resources is arequirement addressed in the Breaux ActSection 303(d). Section 303(d)(1)requires that, “In implementing,maintaining, modifying, or rehabilitatingnavigation, flood control or irrigationprojects, other than emergency actions,under other authorities, the Secretary,U.S. Army Corps of Engineers [USACE]in consultation with the Director (U.S.Fish and Wildlife Service) and theAdministrator [USEPA], shall ensurethat such actions are consistent with thepurposes of the restoration plansubmitted pursuant to this section”(“plan” refers to the Louisiana CoastalWetlands Restoration Plan of 1993 orsubsequent revisions of that plan).

The purpose as referenced in Section303(b)(2), is as follows: “The purpose ofthe restoration plan is to develop acomprehensive approach to restore andprevent the loss of coastal wetlands inLouisiana. Such a plan shall coordinateand integrate coastal wetlands restorationprojects in a manner that will ensure thelong-term conservation of the coastalwetlands of Louisiana.”

Breaux Act Consistency Requirements(P.L. 101-646, Sec. 303(d)(1))

No procedural guidance yet exists forcarrying out the 303(d)(1) consistencyrequirement. Plans are underway in theNew Orleans District of the USACE todevelop interim procedural guidance inconsultation with U.S. Fish and WildlifeService and the U.S. EnvironmentalProtection Agency. While this guidanceis being implemented within the NewOrleans District, the District will workwith the Mississippi Valley Division toensure that any USACE activity thatwould have an effect on Louisiana’scoastal wetlands is consistent with303(d)(1). As a minimum, actionscovered under this requirement includeplanning, constructing, maintaining,modifying, and rehabilitating any USACEproject whose purpose is navigation,flood control, or irrigation. Examplesinclude maintenance of existingnavigation projects such as the GulfIntracoastal Waterway or the Mississippi

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River Gulf Outlet. Ongoing planningunder the Lower Atchafalaya BasinReevaluation Feasibility Study presents aprime example for application of theSection 303 (d)(1) consistencyrequirement because of overlap in thissystem between management of floodflows and coastal wetland restoration. This consistency requirement also appliesto any of the above-described actions ifthe project pertains to navigation, floodcontrol, or irrigation within or affectingLouisiana’s coastal wetlands.

Breaux Act Restoration Plan/CoastalZone Provision (P.L. 101-646, Sec.

303(d)(2))

Existing procedures of the CoastalManagement Division used inimplementing Coastal Zone ManagementAct Federal Consistency would beavailable to the State for reviewing allfederal actions after the Coast 2050 Planis incorporated into the State’s CoastalZone Management Program.

Pursuant to 16 U.S.C. 3952(d)(2), theGovernor of the State of Louisiana canrequest, and the Secretary of Commerceshall approve, the restoration plandescribed at P.L. 101-646 Section 303(b)as an amendment to the State’s federallyapproved coastal zone managementprogram. Upon receiving this approval,the restoration plan would then beincorporated into the Louisiana CoastalResources Program (LCRP) and allenforceable policies and mechanisms ofthe State’s coastal zone managementprogram would be applicable underprovisions of the Coastal ZoneManagement Act, 16 U.S.C. Section

1456. This document, Coast 2050:Toward a Sustainable CoastalLouisiana, represents such a restorationplan.

The Governor’s request is to be madethrough the Secretary of Commerce andprocessed in accordance with the rulesand procedures pertaining toamendments to federally approvedcoastal zone management plans at 36CFR 923.80-84. Such a request has beenmade by the Governor of Louisiana incorrespondence dated November 28,1995 (Appendix A).

Once incorporated into the LCRP,activities of Federal agencies would bereviewed for consistency with therestoration plan pursuant to the FederalConsistency authority granted to theState by 16 U.S.C. 1456. This reviewwould be conducted by using the currentreview procedures of the LouisianaDepartment of Natural Resources,Coastal Management Division.

Breaux Act Conservation Plan Implementation Requirements

(P.L. 101-646, Sec. 304)

In November 1997, the State ofLouisiana received federal approval of itsCoastal Wetlands Conservation Plan, inaccordance with Section 304 of theBreaux Act. This document details theState’s ongoing efforts to achieve a “no-net-loss” of wetlands from all futuredevelopment. The plan is based largelyon public education, mitigation ofunavoidable losses, and implementationof State-funded restoration projects andprograms. An advanced data

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management system has been implementedto improve the State’s ability to trackwetland losses that occur throughdevelopment as well as to track the results ofmitigation implementation. Within 2 years,or by mid-2000, the approving Federalagencies must report to Congress whetherthe plan’s implementation has achieved the“no-net-loss” goal. The State was granted areduction from 25% to 15% cost shareobligation on the Breaux Act constructionprojects upon approval of the plan inDecember 1997.

Losses of wetlands resulting from ongoingdevelopment present both ecological andregulatory complications. Both the USACENew Orleans District and the State ofLouisiana Department of Natural Resources(DNR) carry out regulatory programs aimedat minimizing wetland losses andcompensating for unavoidable wetlandlosses. Both agencies have evolving datamanagement systems to track developmentin wetlands and mitigation actions to offsetunavoidable losses. It is therefore importantthat both agencies coordinate their activitiesand share pertinent aspects of thisinformation with the Coast 2050 Planimplementation process.

During the development of the LouisianaCoastal Wetlands Conservation Plan, DNRreported on development-related activities inwetlands, based on an account of the numberof permits issued and resulting acreage ofwetlands disturbed. The 15-year accountingperiod that started in 1980 showed adominance of oil and gas activity in terms ofpermit numbers. It is important to considerthe acreage of wetlands affected by eachpermit. For instance, levee construction orresidential subdivision development mayimpact many more acres under one permit

than the average impact per oil/gas permit. Over the reporting period, DNR reported anaverage annual impact to wetlands of 893acres based on USACE information. It wasnoted, however, that the USACE regulatesthese wetland losses and requirescompensatory mitigation in many cases. It isestimated that about 200 lost acres per yearare unmitigated. It is important to recognizethat little field data exist to verify theseestimates. Through DNR’s implementationof its Coastal Wetlands Conservation Plan,more exact tracking of wetland losses andgains related to development will beconducted. Reevaluation of the estimatedlosses shown above will occur annually andmitigation adjustments will be made asnecessary. For more information aboutnumbers of permits by activity type, seeAppendices C-F.

Beneficial Use of Dredged Material

One activity that is often associated with theState’s consistency program (although notexclusively so) is the beneficial use ofmaterial dredged to maintain navigationchannels. Sediment represents one of themost important resources for buildingwetlands. Dredging activities in Louisiana,including maintenance of Federal navigationchannels and permitted activities inLouisiana’s coastal zone, account for theremoval and redeposition of 90 to 120million cubic yards of sediment annually. Current Federal policy, physical andchemical characteristics of the dredgedmaterial, logistics, and economics limit thebeneficial use of this sediment to createand/or restore wetlands. The increasedbeneficial use of this dredged materialresource must be an integral part of the planto reduce Louisiana’s yearly coastal landloss.

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If one assumes a standard water depth of 5feet with an allowance of one foot forsubsidence/compaction, and a usable volumeof material at 40 million cubic yards, onecould possibly create about 6 square miles ofsubaerial wetlands each year. Theapproximate annual loss of wetlands inLouisiana is 30 square miles per year. Thus,the potential for the beneficial use ofdredged material to address Louisiana’scoastal land loss is significant.

Beneficial use of dredged material resources,as envisioned within the context of the Coast2050 initiative, can take on any of severalforms. Beneficial use is any use whichwould protect, enhance, or provide aplatform for the restoration of vegetatedwetlands. Such uses could include theimpacting of some vegetated wetlands if thelong-term result is the protection or net gainof vegetated wetlands.

Over the last decade there have beennumerous examples of beneficial use ofdredged material. The current status of thiseffort is described in Appendices C-F(Dredging Histories for Federally MaintainedNavigation Channels). The USACE and theState of Louisiana have used dredgedmaterial resources to create over 7,000 acresof subaerial land which has becomevegetated wetlands. This usage has occurredin conjunction with maintenance dredging offederally maintained navigation channels, aswell as through jointly funded effortsutilizing USACE authorities (e.g., Section204) matched by the state.

It has been the USACE’s practice that, aslong as the effort to achieve beneficial use iswithin the project’s base plan or Federalstandard cost, the USACE can and will makebeneficial use of dredge material resources.

If, however, the cost exceeds the Federalstandard or base plan, beneficial use will notbe made unless additional funding from someother authority and/or source can be foundto cover those costs which exceed the baseplan costs.

Through its legislature, Louisiana has statedits policy with respect to beneficial use ofdredged material resources inR.S.49:214.32(F):

“the Secretary (of DNR) shall insure thatwhenever a proposed use or activityrequires that dredging or disposal of fivehundred thousand cubic yards or more ofany water bottom or wetland within thecoastal zone, the dredged material shallbe used for the beneficial purposes ofwetland protection, creation,enhancement or combinations thereof...”

Examples of additional sources of authorityand funding for beneficial use include otherUSACE authorities, such as Section 204,Section 1135, Section 115, or nonfederalfunds which are provided by local sponsors,including states, local government, portauthorities, etc.

There are a number of strategies that, whenused either singly or in concert, could lead tothe beneficial use of more of this materialresource. Some of these strategies are listedbelow.

C Seek additional Congressional authorityand funds to allow USACE to performmore beneficial use during navigationchannel maintenance.

C Seek Congressional assistance to have“Federal Standard/Base Plan” fundingformula changed to include beneficialuse.

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C Seek Congressional/State authorizationand/or funding for USACE to constructwetlands using dredged materialresources.

C Seek funding through the Louisiana StateWetlands Authority and/or Breaux Actfor a yearly supplement to fund beneficialuse projects, either in concert withUSACE supplemental funding, or as an“add-on” to maintenance events fundedwith state/Breaux Act funds.

C Seek Clean Water Action Plan supportfor increased beneficial use as a means ofachieving a portion of the 100,000acres/year increase in wetlands that itcalls for by the year 2005.

C Seek additional funding for the USACEso that the materials currently beingplaced in ocean dredged material disposalsites can be used beneficially and thenseek de-designation of all those sites.

C Seek additional funding and authority torequire “compensatory” mitigation fordredged material not used beneficiallyfrom maintenance of Federal navigationchannels and permitted activities in theLouisiana coastal zone.

Programmatic Strategies

During the course of the Coast 2050planning initiative, many ideas weresuggested by the Regional Planning Teamsand the public that are programmatic ratherthan physical in nature. These concepts werecarried through the entire process in a similarfashion as the regional and mapping unitstrategies. They are presented below asrecommendations that have the potential toimprove implementation efficiency of

authorized restoration projects, improveeffectiveness of future restoration efforts,improve the coordination among existingenvironmental resource programs, or resultin actions that may benefit coastal wetlandsin other ways.

Coastwide Programmatic Recommendations

Coordinate mitigation with restoration planobjectives and priorities

During the permitting process, whencompensatory mitigation for unavoidableimpacts to coastal resources is beingnegotiated, regulatory authorities should, ifwithin statutory limits, make certain thatmitigation plans are consistent withrestoration plan objectives. Compensatorymitigation projects have far-reachingpotential for wetland creation, enhancement,and protection efforts in the coastal zone,and this strategy is designed to capture thispotential.

Provide appropriate relocation costs andadequate flood control for impacts related

to wetland restoration projects

This strategy is to ensure that wetlandrestoration projects include, at the outset,provisions to adequately mitigate forpotential damages that may be incurred as aresult of that project. Flooding impacts,both primary and secondary, from wetlandrestoration projects should be anticipated inthe design phases of those projects. Projectsshould include specific, detailed provisions toaddress those impacts. For example, if ariver diversion is likely to result in flooding,avoidance of damages or compensation forproperty damages should be included as acost of the project. If appropriate, oyster

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lease issues should be addressed inaccordance with Louisiana’s laws andregulations (R.S. 56:432.1 et seq., and LAC43:I§850-858).

Expedite permitting of coastal restoration projects

Despite efforts to streamline permitting ofregulated activities in jurisdictional wetlands,securing the necessary authorizations can betime-consuming, even for those projects thatare considered beneficial. Development ofadditional Federal and State general permitsor perhaps special exemptions would reducepermitting time and allow beneficial projectsto be implemented in a timely manner.

Impose and enforce wake limits in areaswhere bank erosion caused

by wakes is severe

This strategy is designed to reduce boatwakes, thereby decreasing wave energy andreducing erosion on shorelines and banks. The strategy is to work with enforcementagents and post speed limits on portions ofwaterways most susceptible to erosion.

Implement best management practices toimprove wetlands and associated aquatic

habitats and address other water quality issues

This strategy would entail the coordinationwith other State and Federal agencies suchas Department of Environmental Quality,Department of Transportation andDevelopment, Natural ResourcesConservation Service, Soil and WaterConservation Commission, LouisianaDepartment of Wildlife and Fisheries andU.S. Environmental Protection Agency toimplement best management techniques for

such practices as forestry, agriculture,marinas, urban development, and hydrologicmodification.

Improve land rights acquisition procedures

This strategy involves working withlandowners to secure rights to buildrestoration projects or to increase acreage ofwetland habitats through donations, Federaland State incentive programs, easements,etc.

Increase wetlands though incentive-based programs

Marsh and swamp acreage could beincreased by converting unused agriculturefields, pastures, and grazing areas to theiroriginal wetland habitats through such effortsas the Wetland Reserve Program, which isadministered by the Natural ResourcesConservation Service.

Identify funding sources that match the scaleneeded to adequately address the coastal

land loss problems in Louisiana

This strategy involves determining additionallevels of funding required to adequatelyoffset Louisiana’s coastal land loss and toimplement appropriate actions to secure suchfunds.

Prevent the negative effects of shell dredging

Shell dredging should be administered insuch a way that environmental damages,including but not limited to wetland effects,are avoided or mitigated.

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Mitigate water hyacinth problems to reduce marsh erosion

Water hyacinth is an exotic plant that, underoptimal growth conditions, can form floatingmats of vegetation that can weigh many tons. When these huge rafts are blown or carriedby currents against or onto a bank ofemergent wetland vegetation, severe damageand ensuing erosion may be sustained. Ininstances where water hyacinth may be animportant factor in erosion rates, stepsshould be taken to prevent associatedproblems from occurring.

Develop and support a comprehensivebarrier shoreline/island initiative to expedite

appropriate actions such as mitigation ofdamages and restoration

of these critical areas

Barrier shorelines, headlands, and barrierislands are important for a number ofreasons. Therefore, consideration should begiven to the formation of an initiative thatfocuses on problems, potential solutions, andother issues related to these areas.

Regional and Mapping Unit Programmatic Recommendations

Region 1

In the Lake Pontchartrain mapping unit (Fig.7-3), water quality improvements weresuggested, particularly as related to sewerdischarge. Three related concerns were alsovoiced: the desirability of a continued drillingmoratorium, a continued ban on shelldredging, and improved management of fillmaterial (Appendix C).

The Region 1 Regional Planning Team alsosuggested that in the Lake Borgne, Biloxi

Marshes, and Eloi Bay mapping units,restrictions should be placed on oysterharvesting in the near-shore zone, so thatextensive reefs might become established inthese areas and protect the shorelines fromerosion, provide shell hash to the system, andimprove water quality.

The Regional Planning Team identifiedseveral tracts where opportunities may existfor the inclusion of additional lands protectedas special status areas. These were areas inLake Maurepas and Manchac Land BridgeWest mapping units to be considered asNational Estuarine Research Reserves; theManchac Land Bridge East to be consideredas an extension of the Joyce and ManchacWildlife Management Areas; and theLaBranche Wetlands unit was recommendedas an addition to the Bayou SauvageNational Wildlife Refuge.

The Tchefuncte River mouth was identifiedas an area where drainage and developmentof marsh lands should be reduced, while thePearl River Mouth was suggested as an areawhere dredging should be restricted. In theNorth Shore Marshes, flood controlmeasures were recommended to becoordinated with the Coast 2050 restorationstrategies. In addition, a 36-foot draft limitwas proposed for the Mississippi River GulfOutlet.

Region 2

In the Baker and Des Allemands mappingunits (Fig. 7-6), the Regional Planning Teamrecommended that selective harvesting oftrees planted in mitigation banks be allowed. In the Lake Washington/Grand Ecaille andBastion Bay mapping units, the RegionalPlanning Team recommended that theproblem of salinity intrusion be studied,

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particularly the possibility of intrusion via thehurricane protection levee borrow canal(Appendix D).

Barrier island restoration and protection wasan issue that was deemed to warrantprogrammatic consideration, e.g., therestriction of sand mining on islands andridges in the Fourchon mapping unit. InCaminada Bay, it was suggested thatalternative sources of sediment, such as redmud, compost, etc., be considered forrestoration purposes.

Region 3

Several programmatic strategies originatingin Region 3 were moved into the coastwidestrategy section due to their widespreadapplicability, i.e., those dealing with shelldredging effects, river water studies, waterhyacinth, and a barrier island/shorelineinitiative.

In addition, the Regional Planning Teamproposed a far-reaching recommendation toestablish multipurpose control of the HoumaNavigation Canal, including freshwater andsediment retention and distribution, salinitycontrol, hurricane protection, and navigationfacilitation. In the wetland area immediatelyadjacent to the Houma Navigation Canal, itwas recommended that there be a wake limitestablished and enforced, that floodprotection be established on both sides of thecanal, and that the Falgout Canal project’swater management plan be amended. TheField’s Swamp mapping unit (Fig. 7-9) wasanother area where wake limits weresuggested (Appendix E).

In the Timbalier Island Shorelines and IslesDernieres Shorelines units, the RegionalPlanning Team suggested that new dredging

of canals be eliminated, directional drilling beutilized to prevent new developmentfootprints on the islands, and that mitigationefforts should be directed at restoring theislands.

In Mechant-de Cade, water quality andwastewater management wererecommended. In Big Woods, the RegionalPlanning Team advocated the protection ofthe groundwater recharge area betweenPerry and Big Woods from salinity intrusion. In the St. Louis Canal unit, flood protectionwas cited as a recommendation, and in theDevil’s Swamp mapping unit, leveemaintenance and water quality improvementwere recommended.

Region 4

In Region 4, the Regional Planning Teamidentified a number of programmaticrecommendations, many of which are relatedto existing hydrologic and salinity problems,or additional problems considered likelyshould the proposed Trans-Texas Water Planbecome a reality. In general, these strategiesinvolve funding and undertaking a study orstudies that would provide the neededinformation to accurately anticipate thepotential effects of a Trans-Texas Water Planscenario and to develop contingency plansthat would mitigate these effects should theTrans-Texas Water Plan happen. Information is needed concerning the effectson year-round salinity patterns under variousconditions, including drought; and todetermine the ramifications of this onwetland loss and conversion rates, andresulting consequences on fish, wildlife,water supply, and other resources. Thosemapping units (Fig. 7-12) the RegionalPlanning Team suggested may be mostvulnerable to such adverse impacts are Black

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Bayou, Perry Ridge, South West Gum Cove,Sabine Lake, Sabine Lake Ridge, SoutheastSabine, Willow Bayou, and West Johnson’sBayou (Appendix F).

Another major theme in Region 4 is tomaintain the Grand Lake, White Lake, andSouth White Lake mapping units as low-salinity, fresh-to-intermediate ecosystems, inwhich water levels and hydroperiods wouldbe controlled so as to reduce wetland lossresulting from extended flooding episodes,while at the same time protecting fresh watersupplies for agriculture. These areas wouldprovide limited estuarine access, andfisheries parameters would be monitored atkey locations.

Other programmatic strategies include:addressing the severe bullwhip mortalityproblem in the East Johnson’s Bayou andSecond Bayou mapping units, maintainingridge functions at Johnson’s Bayou Ridge,and restricting sand mining at the GrandChenier Ridge mapping unit. In the LittlePrairie mapping unit, it was suggested thatthe “wiggles” on the Gulf IntracoastalWaterway be straightened out so as toimprove navigation safety and therebyreduce the chances of accident-relatedadverse impacts to wetlands and dependentresources. In Sabine Lake, the RegionalPlanning Team suggested that pollution bereduced by “best management practices.”

Compensation Issues

Abating the loss of wetland functions andvalues in the future may result in somelimited near-term negative impacts. Thesenegative impacts, to the extent they occur,are most likely to be experienced by peopleusing the wetlands for income generation. Though the negative impacts associated with

any given project may be temporary, withduration being related to that period neededfor adjustment to the transition, the issue ofcompensation may arise. Compensation isan issue with the potential to alter projectselection, construction, and operation. Consequently, a policy on compensationshould be developed. This policy wouldinclude whether or not compensation shouldbe extended to commercial harvesters otherthan those addressed in the currentlyproposed Oyster Lease Relocation Program.

Insight can be found by reviewing instancesof public direct and indirect support ofcommercial harvesters. Indirect supportoccurs via incentive programs. At least twoprograms in Louisiana involve indirectincentives. The first, Act 164 (R.S. 47:297),was enacted to provide a tax credit againstindividual income tax for Louisiana gasolineand special fuel taxes paid for operating orpropelling any commercial fishing boat. Thesecond indirect incentive entitles commercialfishermen to receive a Louisiana State salestax exemption certificate from theDepartment of Revenue and Taxation (R.S.47:305.20). Both programs require thatcommercial fishing must be the exemptioncertificate holder’s primary source ofincome. Though not related to a specificrestoration project, such mechanisms couldbe a means of compensation. That is, a statepolicy of compensation would not have to beproject specific. The policy could use theestablished programs in recognition of thestatewide approach to restoring wetlands. Parts of the sales tax exemption removed inprior years could be restored. Qualification(licenses) and documentation (tax returns)programs need not be created as they are inplace and familiar to agencies processingapplications.

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Other Louisiana programs such as theCommercial Fisherman’s Gear CompensationProgram involve direct payments. Damageto fishing gear and boats is compensatedfrom a state-administered fund. To beeligible, applicants must receive 50% ormore of their income from commercialfishing.

Compensation programs at the Federalgovernment level are most often associatedwith natural disaster recovery efforts. Anexample is the Hurricane Andrew DisasterPayments Program to oyster lease holdersand other commercial fishermen. Compensation after natural disasters isfocused on returning the affected businessesto operation. Oyster leaseholders receivedfunds from the U.S. Department ofAgriculture’s Agricultural Conservation andStabilization Service headquartered inAlexandria, Louisiana. This programincluded payments to leaseholders ascompensation for the loss of oysters andremoval of debris from oyster reefs.Payments were made after leaseholders metqualification conditions related to the extentof losses. Among the relevant aspects of thisprogram was the establishment of a thresholdbelow which no payments were received. That is, damage had to first be demonstratedand then judged to be above the thresholdprior to payment.

The program for other commercial fishermendid not attract many applicants in Louisiana. Other gulf states experienced a similar lowapplication and subsequent approval rate. The excess funds were distributed to fisheryagencies in gulf states for use in programsthat could beneficially impact commercialfishermen. The most noteworthy Louisianaprogram is the use of the Federal funds bythe Department of Natural Resources to

identify and remove bottom obstructionsdeemed hazardous to both navigation andfishing gear use. This indirect approach maybe suitable for restoration projects ifgovernmental policy includes compensation. It may not be obstruction removal in the caseof public projects but the activities couldinclude: (1) improved navigation aids, (2)improved access via launching ramps, and(3) improved aquatic weed control.

Both Federal and State agencies haveexperience in developing and administeringpayment programs with varied purposes forthe commercial fishing industry. Whether ornot there are prospects of measurabledamage and an obligation to abate impacts isa matter for government to determine. Experience with past programs does notsuggest a specific program. There arecomponents of such programs that must bediscussed if programs are authorized,including:

C Establishing a single statewide programor developing programs for each projectthat meets compensation justificationcriteria,

C Identifying effects to be compensated,

C Establishing qualifications for thoseeligible,

C Identifying project impact areas, i.e., theaffected area parallel of the Oyster Lease Relocation Program,

C Establishing criteria for documentinglosses,

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C Establishing agency procedures andcosts associated with verification ofclaims,

• Establishing the open season period inwhich applications are received,

C Establishing the length of time in whichdamage should be compensated, and

C Establishing the source and estimate theamount of funds necessary for directpayment compensation.

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CHAPTER 9

SCIENCE AND TECHNOLOGY

One of the challenges of implementing aplan as ambitious as Coast 2050 is theintegration of the latest science andtechnology into the detailed planning andengineering phases of the resultingprojects. Often, the planning phases ofmajor landscape projects across thecountry take many years, during whichtime new information becomes availableand the fundamental rationale of theproject is called into question. Thetechnical and scientific problemsidentified during a lengthyimplementation process can be minimizedby ensuring that appropriate research isaccomplished and integrated into theplanning process and project design. TheBreaux Act restoration effort has madestrides towards this goal by incorporatinguniversity scientists into some aspects ofproject selection (e.g., benefits analyses)and planning (e.g., modeling andfeasibility studies), and by allocatingfunds for monitoring for the life ofconstructed projects. As implementationof ecosystem scale managementstrategies begins, outstanding scientificand technical questions should beaddressed and monitoring data andrestoration-oriented research resultsshould be used in adaptive managementand project planning decisions.

The Coast 2050 Plan is based on thecurrent state of knowledge ofLouisiana’s complex coastal ecosystems. The technical aspects of this plan owe

much to the efforts of coastalresearchers, technical agency personnel,coastal land managers, and other localparticipants, but we need to enhance ourcapabilities to both manage coastalsystems (technology) and to predictenvironmental response to those actions(science).

Research Needs and ImprovedUnderstanding

To fully achieve the ecosystem goals setforth in this plan, a better understandingof ecological and biogeomorphicprocesses and functions is needed.Critical questions still need answers, suchas— What is the effect on ecosystemsustainability of a seasonal river diversionthat increases the annual range ofsalinities within the receiving basin? Howimportant to coastal marshes is nutrientinput alone vs. freshwater and sedimentdelivery from the river? How does thisvary with marsh type?

Clearly, there are still many restorationissues in coastal Louisiana that cannot beresolved without additional research. Theresearch must then be integrated into therefinement of the strategies and therevision of the plan. Particular areasneeding more research are:

C Relative contribution of drainageimprovements, nutrients and

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sediment supply in ameliorating thedegradation of cypress-tupeloforests.

C Genesis of and factors controllingsustainability, sensitivity andresilience of floating marshes.

C Water quality impacts of MississippiRiver water diversions throughcoastal wetlands, including thepotential effects of nutrients onhypoxia in the gulf and in inshorereceiving areas. Many workers haveargued that diversions of MississippiRiver water through coastal wetlandswill result in lower nutrient levels inthe gulf, and less potential forhypoxia to develop. In contrast,some suggest that diversions into thecoastal basins with restricted watermovement may result in an inshorehypoxia problem.

C Factors controlling long-termvertical accumulation andsustainability of the marshsurface— the role of storms, theinteractions between sedimentdeposition, organic matteraccumulation and vertical accretion,and the associated variability acrossmarsh types and coastalphysiographic settings.

• Short-term and long-term effects ofcoastal restoration projects onfisheries and wildlife production anddistribution, and the relative meritsof the different project types andfeatures employed to these resources.

Improved Technologies

Restoration Technology

Developments in restoration technologyare required if the Coast 2050 Plan is tomove forward. The plan recognizes thatthe resources of fresh water andsediments are critical to the sustainabilityof the coastal ecosystem. Managingnatural flows and directing sediment toareas of need means manipulating amajor river system on an unprecedentedscale. The engineering design ofstructures, channels and gates mustadvance to facilitate the control of theriver’s resources to meet the ecosystemneeds. For areas where fresh waterand/or sediment are not available,however, additional techniques formaximizing vertical accumulationthrough organic matter production needto be developed.

Another area requiring attention is thestudy of the use of alternative marshcreation materials, such as fiber rolls,waste fill material, vegetative earthreinforcement mats, biodegradable woodfiber erosion control blankets,biodegradable erosion control mats, sodreinforcement fabrics, etc. Hardstructures such as gobi-blocks, siltfences, and geotextile sheets, whichmight hold dredged soil in place to allowfor vegetative plantings or naturalrevegetation, also need to beinvestigated. The effectiveness of thesemeasures in different physical andecological settings should be determinedand the information disseminated to allinvolved in restoration work.

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Predictive Tools

To effectively use existing knowledgeand gain the increased understandingnecessary to deal with the issuesdescribed above, it is essential thatappropriate predictive tools aredeveloped. The tools include numericalmodeling approaches to predictingpatterns of water level, salinity, andsediment distribution. Hydrologicmodels, which specifically encompassflows across marsh surfaces and throughchannels and structures, must bedeveloped. Ecological models mustaddress marsh accretion (mineral andorganic), nutrient budgets, and soilbiogeochemical processes.

Information Needs and Database Development

The Breaux Act has one of the bestdeveloped monitoring programsnationwide for wetland projects. Monitoring funds are routinely allocatedfor the life of constructed projects andmonitoring plans for each project aredeveloped to include statistical designsand the use of reference areas. Becauseof funding constraints, these monitoringefforts are limited to the environmentalparameters expected to be affected bythe projects and are confined to the areaimmediately affected by a project and anadjacent reference area if a suitable onecan be located. As more projects areundertaken, monitoring databases forsome essential variables such as waterlevel and salinity data will coverextensive areas of the coast. Thesecollective data will provide a good starting point to assess the cumulative

spatial and temporal impacts of thenumerous Breaux Act projects on theentire ecosystem.

The implementation of the Coast 2050Plan must encompass monitoring at theecosystem scale, including spatially andtemporally linked coastwide data forattributes such as water levels, currents,salinities and suspended sediments, to aidin planning and to fully assess the rate ofprogress toward the goal of a sustainablecoast. The concept of a coastwidemonitoring program is being explored byFederal and State agencies; establishmentof such a program should be a highpriority. Analysis of this coastwide datashould provide a better understanding ofsystem processes.

A more immediate need is to gathercurrent and accurate bathymetry of waterbodies and topography of marshes andswamps. In the Barataria-TerrebonneNational Estuary Program area, thedetermination of surface elevations hasproved to be a useful planning tool, butthe lack of detailed bathymetry remainsproblematic. A coastwide bathymetryand topography survey is essential toproject, watershed, and ecosystemplanning.

Fundamental databases that describe thecontemporary environment should bedeveloped in a manner that allowsuniversity scientists, agency personnel,land managers, and local interests toaccess and use available information. Such databases should provide access to:(1) coastwide data for attributes such aswater levels, currents, salinities andsuspended sediments, (2) project-specificmonitoring data and evaluations, (3)

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GIS-based information regarding thecurrent status of our coastal systems,especially the bathymetry of water bodiesand topography of marshes and swamps,and the current, ever changing, land-water configuration of our coast, and (4)GIS-based information regardinginfrastructure so that landscaperestoration planners can readilydetermine the location of oil and gaspipelines, roads, levees, etc.

Integration of Science andTechnology— Examples

Three feasibility studies currentlyunderway have already demonstrated thevalue of combining talents in research,engineering, and planning to develop theinformation essential to major publicworks programs. The Barrier ShorelineFeasibility Study, Phase 1, and theMississippi River Sediment, Nutrient andFreshwater Redistribution Study wereboth funded by the Breaux Act in 1996 inresponse to a call from the Governor ofthe State of Louisiana for theexamination of system-scale restorationstrategies. In addition, the USACE inresponse to flood control problemswithin the Atchafalaya Basin and coastalcommunities has funded the LowerAtchafalaya River Reevaluation Study. These studies represent a step forwardfor coastal restoration planning inLouisiana because they:

C Include input from active researchers,

C Use predictive modeling approachesto understanding process dynamics,and

C Examine how restoration strategiescan result in benefits outside theimmediate project area.

In addition, the Lower Atchafalaya RiverReevaluation Study has involved datacollection which has greatly increasedour understanding of delta building andmarsh rejuvenation using fresh water andsuspended sediment. It is essential thatsuch approaches be pursued as the Coast2050 ecosystem scale strategies arerefined by feasibility analyses intoprojects.

The Coast 2050 Science andTechnology Challenge

Participants in the Coast 2050 planningprocess have enough understanding ofcoastal Louisiana and its problems todevelop the strategies presented in thisplan and know that the strategies canaddress some important issues. Thechallenge is to fill in the gaps ofinformation, understanding, andtechnology so that the presentedstrategies can provide their potentialbenefit to the coast. To meet thatchallenge, (1) mechanisms to fund acoordinated program of coastalinvestigations to understand the longerterm dynamics of the system must bedeveloped, (2) research anddemonstrations that specifically advancerestoration technology must beconducted, (3) usable databases must bedeveloped, and (4) mechanisms tointegrate research results into theplanning and design of restorationprojects must be developed.

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CHAPTER 10

REALIZING THE GOAL:PRINCIPLES FOR IMPLEMENTING

THE COAST 2050 PLAN

Development of a detailed agenda forimplementing the Coast 2050 Plan is thenext important step in the Coast 2050Program. The implementation programwill be designed in 1999 and will bebased on the principles set forth below. To move forward in the campaign toensure sustainability of Louisiana’svaluable coastal resources, challengesthat presently delay project constructionmust be embraced and solved.

Some important issues will emerge asdetailed planning is undertaken. TheBreaux Act process and the ongoingefforts of the State of Louisiana andprivate landowners to restore the coasthave already shown that there are someissues that need immediate attention.Some of these problems have beenhighlighted here. It has not thus far beenthe goal of the Coast 2050 planningeffort to resolve these issues; rather, thepurpose here is to point to the actionitems most critical to successfulimplementation of the Coast 2050ecosystem strategies.

Measures of Success

Short Term

In the short-term, the success of theCoast 2050 Plan will be measured by twothings. The first is the extent to which alarge number of strategic restoration

projects are quickly planned, implementedand operated effectively. The second isthe extent to which regulatory andinfrastructure programs are quickly andeffectively aligned toward the Coast 2050restoration goals.

Action Items:

C Ensure that existing Breaux Act fundsare directed towards strategiesincluded in the Coast 2050 Plan. TheBreaux Act Task Force has alreadytaken steps in this direction byensuring that the next Priority ProjectList considers Coast 2050 strategies.

C Initiate review of regulatory programsto determine specific modificationsneeded to enhance implementation ofCoast 2050 strategies.

Long Term

The Coast 2050 Plan seeks to provide themaximum productive acreage andproductivity from the coastal ecosystem. In the long-term, success will be measuredby the quantity, diversity, and quality ofwetland acreage, and the resulting benefitsfrom various services to Louisiana and thenation. These benefits include protectionagainst storms and floods, production offisheries and wildlife resources, protectionof water supply and wastewaterassimilation capacity, and support to

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activities such as oil and gasdevelopment, navigation, andecotourism.

Action Item:

C Develop a coordinated approach toevaluation of ecosystem value andrestoration including, but not limitedto, wetland acreage, measures ofsecondary productivity, biodiversityindices, and population/infrastructuredevelopment.

These measures— strategic projects,regulatory reform, and wetlandsbenefits— will be the focus of theimplementation effort.

Scale of Success

The strategies set forth in this planconstitute the nation’s (and world’s)largest and most ambitious program ofecosystem restoration. One measure ofthe scale of this undertaking is tocompare the investment that is nowbeing made in coastal restoration to theamount of funds needed to accomplishCoast 2050.

Construction aspects of the Coast 2050Plan would likely require spending $14billion or more over the next 30 years. The current Breaux Act program investsless than 10% of that amount, which is aprimary reason why it can achieve onlylimited and localized restoration benefits. Thus, Coast 2050 envisions at least atenfold increase in the effort that willbe made to restore Louisiana’s coastalwetlands.

The large increase in effort is requiredbecause the current program will addressonly 22% of the land loss problems. Thestrategies put forth in Coast 2050 arelarger, more ambitious, more productive,and more costly than projects that can befunded under the current program. Thecost increase also reflects the fact thatmost small, inexpensive projects thatcontribute to restoration have alreadybeen funded. The implementation effortmust emphasize steps needed to putlarge, strategic projects on the ground.

Action Items:

C Identify potential fundingmechanisms for key ecosystemstrategies and embark uponpreliminary reconnaissance studies toprovide the information required bythose mechanisms.

C Quantify the resources and identifythe source of cost-share funds andservices.

Ingredients for Success

Coastal Louisiana is on the verge ofecosystem collapse. With that collapsecomes an immeasurable cost to humancommunities and the national economy.Thus, the implementation plan mustprovide a fast track to substantialaccomplishments, if we expect to reachthe overarching goal of a sustainedcoastal ecosystem that supports andprotects the regional and nationaleconomy. There are four essentialfoundation blocks for successfulrestoration. Getting each in place quicklywill be the primary objective of theimplementation program.

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Commitment

Coast 2050 cannot succeed unless thereis a public will to achieve large-scalerestoration. The Breaux Act programwas born from a fundamentalcommitment on the part of Louisianacitizens and their representatives thatcoastal restoration is among the highestof society’s priorities. A substantiallyenlarged program will require these samecitizens and representatives to renew andexpand their commitment. Thecommitment must be shared at thenational level.

Action Item:

C The State of Louisiana must show itslegislative and fiscal commitment toecosystem sustainability andchallenge the Federal government torespond.

Knowledge

The unprecedented scale of action that isenvisioned by the Coast 2050 Plan willtest our ability to understand, predict,and manage the effects of restorationactions on coastal ecosystems. It will beimperative to support the Plan throughan extensive program that acquires dataon coastal resources and processes, thatinterprets these data through state-of-the-art hydrologic and ecologicalmodels, that develops safety net featuresto address risks and unintendedconsequences, and that applies theresults of our knowledge throughadaptive management of restorationprojects and activities.

Action Item:

C The State and its Federal partners mustdemonstrate their commitment bydirectly supporting programs to increasethe knowledge base, develop thepredictive tools, and make thetechnological advances necessary toimplement Coast 2050 strategies.

Process

Decisions on specific Coast 2050 actionswill require a planning and implementationprocess that has extensive publicinvolvement and effective incorporation ofpublic values. This process must integratethe restoration program into the entirefabric of coastal activities and must ensurethat restoration is accomplished withimpacts on coastal communities and thecoastal economy that are acceptable, or thatare dealt with equitably throughcompensation and other programs.

Action Item:

C Impediments to the implementation ofrestoration projects such asdetermination of land ownership,resolution of surface-mineral rightsconflicts, compensation for damagesand access to public resources must bemore efficiently addressed.

Resources

Finally and perhaps most fundamentally,implementing Coast 2050 will require alarge increase in resources directed atcoastal restoration. These include fundingthat is at least 10 times greater than nowavailable to put the key strategies on theground and the personnel needed to plan,develop, build, and manage large-scaleprojects and to streamline regulatoryprograms. Without such funding, the

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coast will be lost.

Urgency of the Coast 2050 Plan

Action must be fast. The Coast 2050Plan was developed over 18 months andinvolved hundreds of people. Thecommitment of the public to this plan isbased on the expectation that it willmake a difference in the coastal

landscape before it is too late. Lessonslearned in this process need to be used tomake future planning andimplementation efforts more effective. Allelements of the Coast 2050 Plan cannotbe implemented within five or even tenyears, and a detailed implementation planstill needs to be developed. However,there are many issues which local, State,and Federal interests can addressimmediately. Without the commitment totake these first steps, the Louisianacoastal ecosystem will collapse. Theneed for action is clear. The time foraction is now.

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Documents

Coast 2050: Toward a Sustainable Coastal Louisiana...Coast 2050: Toward a Sustainable Coastal Louisiana, The Appendices. Suggested citation: Louisiana Coastal Wetlands Conservation