SEDIMENTATION CONTROL TO REDUCE MAINTENANCE DREDGING OF NAVIGATIONAL FACILITIES IN ESTUARIES

Report and Symposium Proceedings

Committee on Sedimentation Control To Reduce Maintenance Dredging in Estuaries

Marine Board Commission on Engineering and Technical Systems

National Research Council

National Academy Press
Washington, D.C.,
1987



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings SEDIMENTATION CONTROL TO REDUCE MAINTENANCE DREDGING OF NAVIGATIONAL FACILITIES IN ESTUARIES Report and Symposium Proceedings Committee on Sedimentation Control To Reduce Maintenance Dredging in Estuaries Marine Board Commission on Engineering and Technical Systems National Research Council National Academy Press Washington, D.C., 1987

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings 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 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 Sciences, the National Academy of Engineering, and the Institute of Medicine. The views expressed in the individual papers in the Proceedings are those of the authors. They are not necessarily endorsed by the National Research Council, nor the agencies that sponsored and participated in the Symposium. 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 government on scientific and technical matters. Dr. Frank Press 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 outstanding 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 program aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M.White 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. Samuel O.Thier is president of the Institute of medicine. The National Research Council was established 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 of 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 engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Frank Press and Dr. Robert M.White are chairman and vice chairman, respectively, of the National Research Council. The program described in this report is supported by Contract No. 14–12–0001–30228 between the Minerals Management Service and the National Academy of Sciences. Limited copies are available from Marine Board Commission on Engineering and Technical Systems National Research Council 2101 Constitution Avenue, NW Washington, DC 20418. Printed in the United States of America

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings COMMITTEE ON SEDIMENTATION CONTROL TO REDUCE MAINTENANCE DREDGING OF NAVIGATIONAL FACILITIES IN ESTUARIES CHAIRMAN Ray B.Krone Department of Civil Engineering University of California Davis, California Scott A.Jenkins Center for Coastal Studies Scripps Institution of Oceanography La Jolla, California Ashish J.Mehta Coastal and Oceanographic Engineering Department University of Florida Gainesville, Florida Charles R.Roberts Chief Engineer Port of Oakland Oakland, California Hsieh Wen Shen Department of Civil Engineering University of California Berkeley, California Henry B.Simmons U.S. Army Corps of Engineers (Retired) Vicksburg, Mississippi Leonard Van Houten L.E.Van Houten and Associates Greenwich, Connecticut Government Liaison James A.Bailard U.S. Navy Civil Engineering Laboratory Charles W.Hummer, Jr. U.S. Army Corps of Engineers Dredging Division Paul G.Teleki U.S. Geological Survey Staff Martin J.Finerty, Jr., Program Officer Janet J.Crooks, Senior Secretary Delphine D.Glaze, Word Processor

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings MARINE BOARD of the COMMISSION ON ENGINEERING AND TECHNICAL SYSTEMS William C.Webster, Chairman University of California Berkeley, California Richard T.Soper, Vice Chairman American Bureau of Shipping Paramus, New Jersey Roger D. Anderson Cox’s Wholesale Seafood, Inc. Tampa, Florida Kenneth A.Blenkarn Amoco Production Company (Retired) Tulsa, Oklahoma Donald F. Boesch Louisiana Universities Marine Consortium Chauvin, Louisiana C.Russell Bryan U.S. Navy (Retired) St. Leonard, Maryland F.Pat Dunn Shell Oil Company Houston, Texas John Halkyard Offshore Technology Corporation Escondido, California Eugene H.Harlow Soros Associates Consulting Engineers New York, New York Charles D.Hollister Woods Hole Oceanographic Institution Woods Hole, Massachusetts Peter Jaquith Bath Iron Works Bath, Maine Kenneth S.Kamlet A.T. Kearney, Inc. Alexandria, Virginia Don E.Kash University of Oklahoma Norman, Oklahoma Warren Leback Puerto Rico Marine Management, Inc. Elizabeth, New Jersey Ernest L.Perry Port of Los Angeles (Retired) Sun City, Arizona Richard J.Seymour Scripps Institution of Oceanography La Jolla, California Sidney Wallace U.S. Coast Guard (Retired) Reston, Virginia STAFF Charles A.Bookman, Director Donald W.Perkins, Associate Director Richard W.Rumke, Senior Program Officer Martin J.Finerty, Program Officer (resigned January 21, 1987) Celia Chen, Program Officer C.Lincoln Crane, Program Officer Doris C.Holmes, Adm. Associate Aurore Bleck, Senior Secretary Janet J.Crooks, Senior Secretary Joyce B.Somerville, Adm. Secretary

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings CONTENTS Preface   vii Executive Summary   ix PART I.  REPORT OF THE COMMITTEE ON SEDIMENTATION CONTROL TO REDUCE MAINTENANCE DREDGING OF NAVIGATIONAL FACILITIES IN ESTUARIES   1     Introduction   2     Conclusions and Recommendations   4     Overview of Symposium Technical Sessions   8     Session A:  Sediment Sources and Transport Processes   8     Session B:  Existing Facility Modifications   12     Session C:  Optimizing Dredging Procedures   15     Session D:  Dredged Material Disposal Considerations   17     Session E:  New Facility Design Considerations   21 PART II.  PROCEEDINGS OF THE SYMPOSIUM   25     Opening Remarks— R.B.Krone   26     Keynote Address— RAdm. J.R.Ives, U.S.N.   28 Session A:  Sediment Sources and Transport Processes   31     Sources of Estuarine Sediment and Their Coagulation R.J.Gibbs   32     Cohesive Sediment Transport Processes A.J.Mehta   53     Field Measure of Cohesive Sediment Behavior in Estuaries R.Kirby   77     Numerical Modeling of Estuarine Hydrodynamics and Dispersion of Cohesive Sediments Y.P.Sheng   94     Modeling Estuarine Sediment Transport Processes A.McAnally   118

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings Session B:  Modifying Existing Facilities   127     Reducing Sedimentation Rates in Harbor Facilities R.B.Krone   128     Controlling Sedimentation in Harbor Berthing Areas Using Scour Jet Array Systems J.A.Bailard   141     Passive Remedial Sedimentation Control in Parallel Berths and Channels S.A.Jenkins   153 Session C:  Optimizing Dredging Procedures   177     Characteristics of Estuarine Dredging Equipment T.Richardson   178     Overdredging to Reduce Dredging Frequency M.Trawle   188     Environmental Considerations During Dredging Operations J.Lunz   198     Hydrographic Surveying E.D.Hart   221     Case History: Savannah Harbor H.B.Simmons   232 Session D:  Dredged Material Disposal Considerations   239     Landfill Problems in San Francisco Bay F.Boerger   240     Problems Associated With Upland Disposal of Dredged Material from Tampa Bay W.K.Fehring   245     Selection of Sites for Open-Water Disposal W.E.Pequegnat   256     Equipment Effects W.R.Murden   269 Session E:  New Facility Design Considerations   277     Planning Considerations for Ports in Cohesive Sediments E.J.Schmeltz   278     Sedimentation Considerations in Designing or Modifying Ports J.Korsgaard   289     New Facility Design Issues as Considered by Marine Terminals Users C.L.Crane and R.B.Harley   300     New Facility Design Considerations: Resources for Formulating a Database G.Pickering   313     Budget of Sediments for Estuarine Harbors D.L.Inman and S.A.Jenkins   328 APPENDIX A:  Committee Membership and Expertise   338 APPENDIX B:  Participants   340

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings PREFACE The filling in of river channels, harbors, and estuaries by river-borne sediments is a relentless process, and one that brings with it a high cost to society. Keeping channels and harbors navigable for commerce and defense can require constant dredging, or some means of otherwise diverting sediment or keeping it moving away from channels and harbors. The price tag for this activity in the United States is about a half billion dollars a year—and it is increasing. In response to a request by the U.S. Navy to assess what is known about sedimentation processes—transport, flocculation, settling, shoaling, and erosion—and ways to lessen the financial burden of maintaining navigable waters, the Marine Board of the National Research Council initiated this study. Reducing the sediments associated with navigational facilities, especially access channels and berths around piers, is an issue of serious national importance. Yet the principal effects of sedimentation are manageable, even though the choice of techniques may be complicated by existing facilities, competing design objectives, and environmental considerations. STUDY SCOPE AND METHODS In 1985 the Marine Board agreed to a request of the U.S. Naval Facilities Engineering Command to appraise sedimentation control technology and practices to reduce maintenance dredging of navigational facilities in estuaries. A committee representing a broad spectrum of expertise was appointed and directed to assess the state of knowledge of sedimentation processes and its application to the problem of maintaining adequate water depths in ports. (See Appendix A for members’ expertise.) The committee was asked to consider three issues: The state of knowledge of sediment types, transport, circulation patterns, and rates of deposition in estuaries and tidal inlets to support the design and installation of navigational facilities for minimal maintenance dredging. The state of technology and practice in sediment management techniques and mitigation systems.

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings Actions needed to improve the state of knowledge, technology, and practice in the management of sedimentation. During its initial discussions, the committee recognized that assessment of management techniques and mitigating systems had to include review of maintenance dredging management and techniques, because in existing harbors improved maintenance dredging techniques may be the only practical means for reducing costs and maximizing readiness. Furthermore, even if facilities are modified to achieve minimum maintenance dredging, periodic dredging may be required and should be accomplished using the most effective technology. The three issues were viewed from overall sediment management and technical perspectives, recognizing that a huge investment may be required in order for existing and new facilities to accommodate deeper draft vessels in the future. The committee convened a symposium that included leading practicing engineers and academicians to obtain pertinent information. (Symposium participants are listed in Appendix B.) Part I of this report presents a synopsis of the papers presented at the symposium, it also contains the committee’s conclusions and recommendations, which are based on the information presented at the symposium and on the experience of the committee members. While the committee’s conclusions and recommendations are not the product of a more comprehensive technical assessment than that presented herein, the committee believes its advice has a high level of validity. Part II is a record of the symposium proceedings. Although the committee recognizes that the papers in these proceedings may contain some duplication of material, they nevertheless offer a wealth of information for federal, state, and port decision makers. ACKNOWLEDGMENTS The committee gratefully acknowledges the generous contribution of time and information provided by the government liaison representatives and their agencies, and the many individuals who participated in the data gathering process. Special thanks are extended to all symposium, participants, both speakers who presented papers and participants who contributed to a stimulating and productive exchange of information. Our appreciation is also extended to the U.S. Army Corps of Engineers and the U.S. Naval Facilities Engineering Command for identifying this project as an issue of national importance to be addressed by the Marine Board.

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings EXECUTIVE SUMMARY Every year in the United States about 497 million yd3 of material are dredged by the U.S. Army Corps of Engineers and private operators to create and maintain navigable waterways and harbors. Without such activity, the natural processes of sediment deposition and shoaling would make many waterways and port facilities impassable by most large commercial and defense vessels. The process of keeping these waters passable is an expensive one—approximately $500 million dollars annually (in 1986 dollars). In addition to the financial cost of dredging, the disposal of dredged material has become more difficult with the passage of laws to protect the marine environment and the consequent dwindling supply of suitable places to put it. Thus, consideration of alternatives to dredging has become an issue with serious implications for this nation’s maritime trade and naval installations. This report addresses the state of knowledge about sediment sources and transport processes; dredging procedures, equipment, and dredged material disposal; and considerations for modifying existing facilities and designing new ones to reduce maintenance dredging. The committee members concluded that despite aspects of sediment transport common to many locations, each harbor, channel, and turning basin is unique, and design or modification to reduce deposition rates be the subject of site-specific study. Three options can be investigated— stopping the sediment before it reaches the site, keeping the material in suspension as it pases through the site diverting the sediment flow away from the site. In its assessment of sedimentation processes the committee concluded that present knowledge can be applied to many existing facilities to reduce sedimentation rates, but that modifying or relocating facilities can be costly. They recommended that sedimentation and sediment management should be considered in the process of selecting sites for new facilities and in planning, design, construction, and operation. Successful application of current knowledge will require field studies. More and better hydrographic data are important for advanced planning.

OCR for page R1
Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries: Report and Symposium Proceedings The committee noted that increasingly restrictive environmental regulations and dwindling disposal sites are putting greater pressures on dredging activities. They therefore recommend that the Corps of Engineers, together with the Environmental Protection Agency and interested agencies, develop long-range plans for managing dredged material disposal for all coastal and estuarine navigation facilities in the United States. Consideration of environmental effects—as well as beneficial uses of dredged materials, such as beach nourishment—are important aspects of such a planning process. Finally, the committee recommends additional research in the areas of estuarine sediment transport processes, development of new sedimentation control methods, and development of design capabilities—such as numerical models—of sediment transport. The cost of a research and development effort, the committee noted, would be a minute fraction of the nation’s dredging bill and would be an investment repaid in cost savings and environmental protection.