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Beach Nourishment and Protection Committee on Beach Nourishment and Protection Marine Board Commission on Engineering and Technical Systems National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1995
National Academy Press · 2101 Constitution Avenue, NW · Washington, DC 20418 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 panel responsible for the report were chosen for their special competences and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sci- ences, the National Academy of Engineering, and the Institute of Medicine. The program described in this report is supported by cooperative agreement no. 14-35-0001- 30475 between the Minerals Management Service of the U.S. Department of the Interior and the National Academy of Sciences and by interagency cooperative agreement no. DTMA91-94-G-00003 between the Maritime Administration of the U.S. Department of Transportation and the National Academy of Sciences. Library of Congress Cataloging-in-Publication Data Beach nourishment and protection / Committee on Beach Nourishment and Protection, Marine Board, Commission on Engineering and Technical Systems, National Research Council. p. cm. Includes bibliographical references and index. ISBN 0-309-05290-4 (alk. paper) 1. Beach nourishment. 2. Shore protection. I. National Research Council (U.S.). Marine Board. Committee on Beach Nourishment and Protection. TC332.B428 1995 627'.58 dc20 Copyright 1995 by the National Academy of Sciences. All rights reserved. Printed in the United States of America Cover: Anna Maria, Florida, beach nourishment project. Photo courtesy of Aero Photo, St. Petersburg, Florida. 95-46578 CIP
COMMITTEE ON BEACH NOURISHMENT AND PROTECTION RICHARD J. SEYMOUR (Chair), Texas A&M University and Scripps Institution of Oceanography NANCY E. BOCKSTAEL, University of Maryland, College Park THOMAS J. CAMPBELL, Coastal Planning and Engineering, Inc., Boca Raton, Florida ROBERT G. DEAN, NAE, University of Florida, Gainesville PAUL D. KOMAR, Oregon State University, Corvallis ORRIN H. PILKEY, Duke University, Durham, North Carolina ANTHONY P. PRATT, Delaware State Department of Natural Resources and Environmental Control MARTIN R. SNOW, Great Lakes Dredge and Dock Company, Chicago, Illinois ROBERT F. VAN DOLAH, South Carolina Department of Natural Resources J. RICHARD WEGGEL, Drexel University, Philadelphia, Pennsylvania ROBERT L. WIEGEL, NAE, University of California, Berkeley (Emeritus) Liaison Representatives MICHAEL K. BUCKLEY, Federal Emergency Management Agency CHARLES B. CHESNUTT, U.S. Army Corps of Engineers (from September 2, 1994) A. TODD DAVISON, Federal Emergency Management Agency JOHN G. HOUSLEY, U.S. Army Corps of Engineers (until September 2, 1994) NICHOLAS C. KRAUS, U.S. Army Engineer Waterways Experiment Station (until November 1994) DAVID E. McKINNIE, National Oceanic and Atmospheric Administration S. JEFFRESS WILLIAMS, U.S. Geological Survey RANDALL A. WISE, U.S. Army Engineer Waterways Experiment Station (from November 1994) Staff CHARLES A. BOOKMAN, Project Officer (from January 20, 1995) WAYNE YOUNG, Project Officer (until January 20, 1995) DELPHINE D. GLAZE, Administrative Assistant LYNN D. KASPER, Editorial Consultant . . .
MARINE BOARD RICHARD J. SEYMOUR (Chair), Texas A&M University and Scripps Institute of Oceanography BERNARD J. ABRAHAMSSON, University of Wisconsin, Superior JERRY A. ASPLAND, Arco Marine, Inc. ANNE D. AYLWARD, Volpe National Transportation Systems Center MARK Y. BERMAN, Amoco Corporation BROCK B. BERNSTEIN, EcoAnalysis JOHN W. BOYLSTON, Argent Marine Operations, Inc. SARAH CHASIS, Natural Resources Defense Council, Inc. CHRYSSOSTOMOS CHRYSSOSTOMIDIS, Massachusetts Institute of Technology BILIANA CICIN-SAIN, University of Delaware JAMES M. COLEMAN, NAE, Louisiana State University BILLY L. EDGE, Texas A&M University MARTHA GRABOWSKI, LeMoyne College and Rensselaer Polytechnic Institute M. ELISABETH PATE-CORNELL, Stanford University DONALD W. PRITCHARD, NAE, State University of New York at Stony Brook STEPHANIE R. THORNTON, Coastal Resources Center KARL K. TUREKIAN, NAS, Yale University ROD VULOVIC, Sea-Land Service, Inc. E. G. "SKIP" WARD, Shell Offshore, Inc. ALAN G. YOUNG, Fugro-McClelland BV Staff CHARLES A. BOOKMAN, Director DONALD W. PERKINS, Associate Director DORIS C. HOLMES, Staff Associate IV
Acknowledgments The committee gratefully acknowledges the contributions of time and infor- mation provided by: Ms. Cheryl Ryder, Environmental Specialist, Florida Department of Environ mental Protection Dr. Walter Nelson, Florida Institute of Technology Dr. Timothy Kana, President, Coastal Science & Engineering, Inc. Mr. J. Thomas Jarrett, Wilmington District, U.S. Army Corps of Engineers Mr. Millard Dowd, Charleston District, U.S. Army Corps of Engineers Mr. Robert W. Lindner, Baltimore District, U.S. Amy Corps of Engineers Mr. David V. Schmidt, Jacksonville District, U.S. Army Corps of Engineers Mr. Michael Kieslich, Galveston District, U.S. Army Corps of Engineers Mr. Adrian J. Combe, New Orleans District, U.S. Army Corps of Engineers Dr. Donald K. Stauble, Coastal Engineering Research Center, U.S. Army Corps of Engineers Mr. Jeff Gebert, Philadelphia District, U.S. Army Corps of Engineers Ms. Monica Chasten, Philadelphia District, U.S. Army Corps of Engineers Mr. John G. Housley, Headquarters, U.S. Army Corps of Engineers v
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal govern- ment on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of out- standing engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Harold Liebowitz is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineer- ing communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce Alberts and Dr. Harold Liebowitz are chairman and vice-chairman, respectively, of the National Research Council.
Preface BACKGROUND Beaches are essential storm barriers. They protect natural and developed areas and provide valuable recreational resources. But beaches are dynamic, often eroding in winter and accreting in summer, moved by waves, currents, and wind. Many beaches are naturally eroding, their shoreline position moving shore- ward over time. Various strategies are used in an effort to manage shorelines to satisfy socioeconomic needs. Fixed structures, such as seawalls, groins, and shore-parallel breakwaters, have been used for many years to create a barrier between land and sea. But they can interrupt the alongshore flow of sand, exac- erbating erosion problems in some instances and creating new ones in others. Beach nourishment, which involves the addition of sand in designed contours to extend a beach and the nearshore shallows seaward, has grown in acceptance as a shore protection and beach restoration measure in the United States, Europe, and Australia. The use of beach nourishment has encountered strong opposition as well as ardent support. Proponents consider the management of littoral sand resources the preferred solution to shoreline erosion. They view beach nourishment as technically and economically sound when projects are well planned and well executed. Opponents often view beach nourishment as little more than building temporary sand dikes to protect against an advancing sea. Some projects have performed well, and others have not, or they have failed to meet public expecta- tions. The mixed results have stimulated considerable controversy. The technol- ogy has been challenged with respect to perceived inadequacies in project loca . . V11
. . . V111 PREFACE lion, prediction, design, monitoring, cost-benefit analysis, sand placement and distribution, cost-share allocations, and the understanding of complex shore pro- cesses. Contributing to the controversy are perceptions about project perfor- mance that are based on anecdotal information rather than technical performance criteria. Section 309 of the Water Resources Development Act of 1990 (P.L. 101- 640) has stimulated considerable public interest in beach nourishment by raising the question of linking federal participation in the planning, implementation, or maintenance of any beach stabilization or nourishment project with a state's establishment or commitment to a beachfront management program. Further, the requirement for a cost share for shore improvements, based on the Water Re- sources Act of 1986, has raised the stakes for states and municipalities, which now have a much more direct interest in the cost and performance of shoreline projects. Given the overall experience with beach nourishment and the growing inter- est and reliance on it, an assessment was needed to establish an improved techni- cal basis for decision making about the use of beach nourishment in shore stabi- lization and management and in the design of beach nourishment projects in which the federal government is involved. THE NRC STUDY As a result of its deliberations and informal discussions with the U.S. Army Corps of Engineers (USAGE), the Marine Board of the National Research Council's (NRC) Commission on Engineering and Technical Systems detained that an improved technical basis for decision making could be established by exploring the engineering, environmental, economic, and public policy aspects of beach nourishment. Important factors meriting assessment include improvements in the. understanding of shore processes; definition of the appropriate role of beach nourishment in shore management; and enhancements and improvements in predictive capabilities, project monitoring, and performance evaluation. The NRC convened the Committee on Beach Nourishment and Protection under the auspices of the Marine Board. Committee members were selected for their expertise and wide range of experience and viewpoints. The principle guiding the constitution of the commit- tee and its work, consistent with NRC policy, was not to exclude members with potential biases that might accompany expertise vital to the study but to seek balance and fair treatment. Committee members are experts in coastal engineer- ing, coastal geology, economics, ecological preservation and response to coastal change, development of beach areas for both public and private uses, and federal and state coastal land-use planning. Academic, industrial, government, scientific, engineering, and public perspectives are reflected in the committee's composi- tion. Biographies of members are provided in Appendix A.
PREFACE IX The committee was assisted by the Federal Emergency Management Agency, the National Oceanic and Atmospheric Administration, the U.S. Geological Sur- vey, and the USACE, all of which designated liaison representatives. The Miner- als Management Service provided information and commentary useful to the committee. The committee was asked by the NRC to conduct a multidisciplinary assess- ment of the engineering, environmental, economic, and public policy aspects of beach nourishment to provide an improved technical basis for judging the use of beach nourishment and protection technology in shoreline stabilization, erosion control, recreational beach creation, dredged material placement, construction of coastal storm barriers and protection of natural resources. Included in the scope of the study are: · measures of beach nourishment project performance; methods for designing and predicting the engineering performance of beach nourishment projects; . . . . . ~ . . engineering, economic, and env~ronmenta requirements for monitoring the performance of beach nourishment projects and developing project monitoring methodology; the potential for improving beach nourishment projects in conjunction with hard structures and other systems, and appraisal of the technical and policy implications; the potential environmental impacts of beach nourishment; and economic issues, including the costs of design, construction, and mainte- nance and the accuracy of prediction, the costs and benefits of beach nourishment relative to other shoreline management alternatives, and a determination of who benefits and who pays. All elements of the beach nourishment system-the borrowing of fill, the transportation of fill to the placement site, the placement of fill, and the possible integration of beach nourishment with hard structures are within the scope of this study. The committee reviewed available data and literature and conducted site visits to determine the state of practice of beach nourishment. The committee also solicited data and views and met with expert practitioners and researchers in federal, regional, and local government agencies; researchers and practitioners in the coastal engineering community; and members of professional societies. In addition, the committee visited beach nourishment projects in Florida (on both the East and West coasts), Maryland, Delaware, and Southern California, and individual members visited other locations. Case studies of specific projects are cited in Appendix B. Appendixes C through I provide technical descriptions and analyses of prediction, design, economic analysis, construction, environmental considerations, and monitoring.
x PREFACE REPORT ORGANIZATION This report was prepared for policy and project decision makers; members of the coastal and civil engineering communities concerned with beach nourishment and shoreline protection; scientists and engineers concerned with prediction, de- sign, construction, and maintenance of beach nourishment projects; and the gen- eral public. Understanding the role of beach nourishment requires an understand- ing of physical processes as well as their socioeconomic and environmental effects. Chapter 1 introduces the beach nourishment concept, discusses regional dif- ferences in physical processes, and frames the issues associated with project decision making. Chapter 2 identifies and discusses management issues. Chapter 3 discusses the roles and responsibilities of federal agencies relative to shoreline protection and the application of beach nourishment. Chapter 4 describes and assesses the state of practice in design and predic tion. Chapter 5 describes environmental issues, assesses monitoring capabilities and needs, and discusses improvements in the state of practice. Chapter 6 discusses physical, economic, and environmental monitoring in the planning, design, and performance assessment of beach nourishment projects. Chapter 7 presents the committee's conclusions and recommendations.
Contents EXECUTIVE SUMMARY 1 INTRODUCTION The Changing Shore, 14 Physical Elements, 20 References, 25 14 MANAGEMENT STRATEGIES FOR SHORE PROTECTION 27 The Decision Process, 27 Project Formulation and Design, 32 Uncertainties, Risk, and the Measurement of Success, 40 Paying for Beach Nourishment, 43 Economic Issues, 45 Public Support for Beach Nourishment, 53 References, 56 3 THE FEDERAL ROLE IN BEACH NOURISHMENT The U.S. Army Corps of Engineers, 58 The National Oceanic and Atmospheric Administration, 61 The Federal Emergency Management Agency, 62 The U.S. Geological Survey, 68 The Minerals Management Service, 70 Erosion Hazard Reduction Programs of Federal Agencies, 71 Xl 58
. ~ All CONTENTS Accrediting Beach Nourishment Projects to Qualify for Flood Insurance Benefits, 73 Addressing Beach Nourishment in the NFIP, 75 A Strategy for Reducing Coastal Hazards, 79 References, 80 4 BEACH NOURISHMENT PROJECT DESIGN AND PREDICTION 82 The Design Process, 83 Nourishment Objectives and Constraints, 83 Significant Processes in Design, 83 Diversity of Settings for Beach Nourishment, 88 Use of Structures and Other Shore Protection Devices in Conjunction with Beach Nourishment, 89 Limitations of Existing Models and Methods, 93 Prediction, 94 Sand Sources A Consideration in Project Design, 97 Sand Bypassing as a Source, 99 Sand Transfer Equipment and Methods, 101 Erosional Hot Spots, 101 Federal Design Procedures, 102 Postconstruction Design Refinement and Corrective Action, 103 Sand Bypass Systems and Hybrid Systems, 104 Professional Accountability for Design, 104 References, 105 5 ENVIRONMENTAL ISSUES ASSOCIATED WITH BEACH NOURISHMENT Subaerial Beach Habitats, 107 Subtidal Beach Habitats, 112 Borrow Source Areas, 115 Restoration of Abandoned Projects, 120 References, 121 6 MONITORING Overview, 127 Physical Monitoring, 130 Biological Monitoring, 134 Economic Monitoring, 136 References, 139 7 CONCLUSIONS AND RECOMMENDATIONS General Findings, 140 Specific Findings, 141 107 127 140
CONTENTS APPENDIXES A BIOGRAPHICAL SKETCHES B PAPERS PREPARED FOR THIS STUDY . . . Xlll 161 166 PREDICTION OF BEACH NOURISHMENT PERFORMANCE 167 D DESIGN OF BEACH NOURISHMENT PROJECTS E ECONOMIC CONCEPTS AND ISSUES: SOCIAL COSTS AND BENEFITS OF BEACH NOURISHMENT PROJECTS F PROJECT CONSTRUCTION AND SEDIMENT SOURCES, TRANSFER, AND PLACEMENT G PHYSICAL PROCESSES MONITORING 189 251 267 294 H U.S. ARMY CORPS OF ENGINEERS DESIGN CRITERIA 31 1 I EXCERPTS FROM FEDERAL LAWS PERTAINING TO PLACEMENT OF SAND FROM CHANNEL MAINTENANCE PROJECTS ON BEACHES INDEX 314 317
XIV 1-1 Terms Used in This Report, 24 BOXES, TABLES, AND FIGURES Boxes Beach Erosion Following the Breaching of Assateague Island, 30 Indication of Level of Public Understanding, 35 Summary Description of Acts Affecting Beach Nourishment, 44 3-2 3-3 3-1 Federal Disaster Assistance Programs for Shore Protection, 63 Potential Hazard Reduction Contributions of a Beach Nourishment Project, 64 Coastal Floodplain Hazard Zones, 65 6-1 2-1 CONTENTS Management Questions Requiring an Effective Monitoring Regime, 128 Information Needed to Plan a Beach Nourishment Project Based on Quantitative Data, 215 Beach Nourishment Monitoring, Ocean City, Maryland, 297 Beach Nourishment Monitoring, Perdido Key, Florida, 298 Beach Nourishment Monitoring, Hilton Head Island, South Carolina, 300 Beach Nourishment Monitoring, Indian Rocks Beach, Florida, 303 Tables Examples of Major Objectives, Criteria, and Approaches for Evaluating Beach Nourishment Projects and Programs, 42 4-1 Estimated Prediction Capabilities, 96 4-2 Potential Sources of Beach Nourishment Sediment, 99 5-1 ld each Nourishment and Beach Disposal Projects Considered Beneficial to Biota Using the Beach or Adjacent Upland Areas, 111 Biological Monitoring Studies that Examined Intertidal and Nearshore Subtidal Beach Habitats Following Beach Nourishment Projects, 116 Physical and Biological Monitoring Studies that Examined Borrow Areas Used for Beach Nourishment Projects, 119 Beach Nourishment Invariants, 185 D-1 Budget of Littoral Sediments, 235
CONTENTS 4-2 4-3 4-4 4-5 4-6 4-7 C-S C-6 C-7 XV Figures General location and number of USACE major shore protection projects with beach nourishment components in the lower 48 states. There is also a beach nourishment project in Homer, Alaska, 19 Ocean City Inlet, Maryland, ebb-tide shoal, 33 Oceanside, California, beach and bluff, 33 4-1 Sand transport losses and beach profiles associated with a nourished beach, 85 Two placement methods for beach nourishment material, 86 Planviews of various scenarios of nourishment placement and stabilization, 89 Shoreline change at Delray Beach nourishment project, 1974-1990, showing shoreline change outside the project area; nourishments involved 2.78 million m3 of material, 90 Calculated example of beach nourishment project evolution, 91 Estimated ability to predict performance relative to various factors that can affect beach nourishment projects, 95 Schematic of design and advanced-fill nourishment profiles, 103 Three phases of observed sediment transport in the vicinity of nourished projects, 168 Variation of sediment-scale parameter, A, with sediment size and fall velocity, 170 Three generic types of nourished profiles, 171 Variation of nondimensional shoreline advancement, /`yOIW*, with A' and results shown for h*lB = 2.0, 172 Variation of nondimensional shoreline advancement, /\yOIW*, with A' and results shown for h*lB = 4.0, 173 Proportion of material remaining, M, in region placed as a function of the parameter, 175 Calculated planform and volumetric evolutions of an initially rectangular beach nourishment project fronting a seawall. Deep-water waves at 10° to shore normal, 184 Design cross-section transferred seaward, 195 Captiva Island beach nourishment monitoring cross-section, 196 Linear design cross-section sometimes intercepts sandbars, providing an underestimate of design fill, 197
XVI CONTENTS D-4 Captiva Island beach nourishment monitoring cross-section at R 98, 198 D-5 D-6 D-7 The construction template, 204 Nourishment profiles, 205 Sand redistribution in the cross-shore direction to form a more natural profile, 206 D-8 Ocean City, Maryland, project profiles, 207 D-9 Nourishment fill performance at Delray Beach, Florida, 216 D-10 Schematic of Delray Beach mean high water versus design, 217 D-l l Captiva Island project showing designed versus actual berm locations in October 1993, 218 Historic barrier island breaching and inlet creation near Westhampton, Long Island, New York, 221 Extremal Type I (Gumbel) distribution of annual maximum wave height statistics based on hindcast data for Atlantic City, New Jersey, 228 Various economic elements of the probabilistic design procedure for a range of beach berm widths, 232 Annual damages as a function of significant wave height and berm width at the start of a storm, 233 D-16 Annual damages as a function of berm width and incident significant wave height, 234 D-17 Sand sources for Ediz Hook, Washington, spit, 236 D-18 Profile envelopes showing depth of profile changes, 238 D-l9 Veneer beach fill cross-section, Corpus Christi Beach, Corpus Christi, Texas, 239 D-20 Veneer beach fill cross-section, Key West, Florida, 240 D-21 Veneer beach fill cross-section, Grand Isle, Louisiana, 242 F-1 Sand bypassing at Indian River Inlet, Delaware. Jet pump positioned by crane, 271 F-2 Layout of a typical offshore cutter dredge, 276 F-3 Schematic of operation of a trailing-suction hopper dredge, 277 F-4 Effect of grain size on production, 282 Sea sled for measuring beach profiles from the dry beach through the surf zone to depth of closure, 302 Coastal Research Amphibious Buggy (CRAB), a sophisticated mobile survey station used to profile the sea bed from the dune through the surf zone out to a water depth of tom, 302
Beach Nourishment and Protection