MITIGATING SHORE EROSION ALONG SHELTERED COASTS
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This study was supported by a contract between the National Academy of Sciences and the following entities: purchase order no. 2W-0373-NANX from the Environmental Protection Agency, purchase order numbers W19HQ-04-P-0132 and W912HQ-05-P-0064 from the U.S. Army Corps of Engineers, contract numbers 04-891 and 05-927 from the Cooperative Institute for Coastal and Estuarine Environmental Technology, and purchase order no. FC133CO5SE6428 from the NOAA Coastal Services Center. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
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COMMITTEE ON MITIGATING SHORE EROSION ALONG SHELTERED COASTS
JEFF BENOIT, Chair,
SRA International, Arlington, Virginia
C. SCOTT HARDAWAY, JR.,
College of William and Mary, Virginia Institute of Marine Science, Gloucester Point
DEBRA HERNANDEZ,
Hernandez and Company, Isle of Palms, South Carolina
ROBERT HOLMAN,
Oregon State University, College of Oceanic Atmospheric Sciences, Corvallis
EVAMARIA KOCH,
University of Maryland, Center for Environmental Science, Horn Point Laboratory, Cambridge
NEIL McLELLAN,
Shiner Moseley and Associates, Houston, Texas
SUSAN PETERSON,
Teal Partners, Rochester, Massachusetts
DENISE REED,
University of New Orleans, Department of Geology and Geophysics, New Orleans, Louisiana
DANIEL SUMAN,
University of Miami, Rosenstiel School of Marine and Atmospheric Science, Miami, Florida
Staff
SUSAN ROBERTS, Study Director
AMANDA BABSON,
Christine Mirzayan Science and Technology Policy Graduate Fellow
SARAH CAPOTE, Senior Program Assistant
OCEAN STUDIES BOARD
SHIRLEY A. POMPONI, Chair,
Harbor Branch Oceanographic Institution, Fort Pierce, Florida
LEE G. ANDERSON,
University of Delaware, Newark
JOHN A. ARMSTRONG, IBM Corporation (retired),
Amherst, Massachusetts
WHITLOW AU,
University of Hawaii at Manoa
ROBERT G. BEA,
University of California, Berkeley
ROBERT DUCE,
Texas A&M University, College Station
MARY (MISSY) H. FEELEY,
ExxonMobil Exploration Company, Houston, Texas
HOLLY GREENING,
Tampa Bay National Estuary Program, St. Petersburg, Florida
DEBRA HERNANDEZ,
Hernandez and Company, Isle of Palms, South Carolina
CYNTHIA M. JONES,
Old Dominion University, Norfolk, Virginia
WILLIAM A. KUPERMAN,
Scripps Institution of Oceanography, La Jolla, California
FRANK E. MULLER-KARGER,
University of South Florida, St. Petersburg
JOAN OLTMAN-SHAY,
NorthWest Research Associates, Inc., Bellevue, Washington
ROBERT T. PAINE,
University of Washington, Seattle
S. GEORGE H. PHILANDER,
Princeton University, New Jersey
RAYMOND W. SCHMITT,
Woods Hole Oceanographic Institution, Massachusetts
DANIEL SUMAN,
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Florida
ANNE M. TREHU,
Oregon State University, Corvallis
Staff
SUSAN ROBERTS, Director
FRANK HALL, Program Officer
SUSAN PARK, Associate Program Officer
ANDREAS SOHRE, Financial Associate
SHIREL SMITH, Administrative Coordinator
JODI BOSTROM, Research Associate
NANCY CAPUTO, Research Associate
SARAH CAPOTE, Senior Program Assistant
Preface
Sheltered coasts, and the bodies of water they surround, are increasingly popular places for people to live, work, and recreate. This is partially due to a preference for a serene setting that is afforded some protection from the full fury of coastal storms. The same sheltered nature of these areas also creates some of the most biologically productive and ecologically valuable resources of the coastal region. But sheltered coasts are indeed subject to erosion and sea level rise, and suffer chronic land loss as a result. The common response by landowners to the loss of their increasingly valuable land has been to “harden” the shoreline by construction of fixed structures such as bulkheads, revetments, or groins. This response can easily create a “bathtub” effect and fundamentally change the character of the coastal environment; in some cases actually worsening the erosion and inundation, and in most cases causing a loss or shift in ecological values. As a better understanding is gained of the physical and ecological impacts of hardening the shoreline, new approaches are being developed for managing eroding sheltered shorelines. This report reviews options available to mitigate erosion of sheltered coasts; explores why certain decisions are made regarding the choice of erosion mitigation options; provides critical information about the consequences or altering sheltered shorelines; and, provides recommendations about how to better inform decisions in the future.
Integrating broad societal and ecological considerations into erosion mitigation strategies is a continuing challenge. Practitioners are slowly moving in that direction and are encouraged to continue on that course. We suggest that more focused research on sheltered coasts, and long-term regional planning early in the process, are key solutions to this chronic issue.
These findings would not have been possible without the hard work, collective action, and perseverance of this committee. I would like to thank my colleagues on the committee for their efforts. Some members are knowledgeable practitioners with hands-on experience working with landowners on the design or permitting of erosion mitigation strategies; others are among the leading researchers in the field of estuarine ecology. I have been honored to serve with such an eminent group and to learn from their wisdom. More importantly, it was a pleasure to get to know them and work alongside them all.
The committee and I gratefully acknowledge and thank the staff of the Ocean Studies Board for their tireless support. Dr. Susan Roberts served as project director for the majority of the project after Dr. Dan Walker was called on for service to another committee. Dan was invaluable for getting us off to a well thought out start and assisting with preparation of the final report. Frank Hall and Susan Park provided valuable assistance during the review process of this report. Sarah Capote was always there for us and provided critical research and logistical support. Amanda Babson also conducted helpful research for the workshop during her internship with the Board.
We hope that the conclusions and recommendations of this report provide meaningful advice to state and federal agencies, local communities, and landowners to guide a new management approach in the planning, design, and construction of erosion mitigation strategies for sheltered coasts.
Jeffrey R. Benoit, Chair
Acknowledgments
This report was greatly enhanced by participants at the two meetings held as part of this study. The committee would like first to acknowledge the efforts of those who gave presentations at the meetings. These talks helped set the stage for fruitful discussions in the closed sessions that followed.
ROBERT BRUMBAUGH, U.S. Army Corps of Engineers
BETH BRYANT, University of Washington, School of Marine Affairs
CHARLES CHESTNUTT, U.S. Army Corps of Engineers
SCOTT DOUGLASS, University of South Alabama
KATHLEEN KUNZ, U.S. Army Corps of Engineers
ROBIN LEWIS, Lewis Environmental Services, Inc.
DAN MILLER, New York State Department of Environmental Conservation, Hudson River National Estuarine Research Reserve
DOUG MYERS, Puget Sound Action Team
KAREN NOOK, U.S. Army Corps of Engineers
NEVILLE REYNOLDS, Vanasse Hangen Brustlin, Inc.
SPENCER ROGERS, North Carolina Sea Grant
HUGH SHIPMAN, Washington Department of Ecology
JAY TANSKI, New York Sea Grant
JOHN TEAL, Teal Partners and Woods Hole Oceanographic Institution
JIM TITUS, Environmental Protection Agency
DWIGHT TRUEBLOOD, National Oceanic and Atmospheric Administration
DON WARD, U.S. Army Corps of Engineers
PHIL WILLIAMS, Phillip Williams Associates, Ltd.
The committee is also grateful to Hugh Shipman, Washington Department of Ecology, and Jeff Parsons, University of Washington, for organizing the committee field trip in the Seattle area. Assistance with conceptual diagrams in Chapter 4 was provided by the Integration and Application Network (ian.umces. edu), University of Maryland Center for Environmental Science.
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for the participation in their review of this report:
BERNARD O. BAUER, University of British Columbia-Okanagan, Kelowna, Canada
MARK BRINSON, East Carolina University, Greenville, North Carolina
ROBERT DALRYMPLE, Johns Hopkins University, Baltimore, Maryland
MARGOT GARCIA, Tucson, Arizona
JORDAN LORAN, Maryland Department of Natural Resources, Annapolis
HUGH SHIPMAN, Washington Department of Ecology, Bellevue
CLIFF TRUITT, Coastal Technology Corporation, Sarasota, Florida
S. JEFFRESS WILLIAMS, U.S. Geological Survey, Woods Hole, Massachusetts
Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by Norbert Psuty, Rutgers University. Appointed by the National Research Council, the reviewers were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.