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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.
Support for this project was provided by the U.S. Bureau of Land Management under Contract No. PAA007017, U.S. Bureau of Reclamation under Contract No. 99-FG-81-0-0154, the U.S. Department of Agriculture Natural Resources Conservation Service and Forest Service under Contract No. 68-3A75-0-170, the National Science Foundation under Contract No. DEB-9909095, the U.S. Environmental Protection Agency under Contract No. CR 826316-01-0, and the U.S. Geological Survey under Contract No. 98HQSA0429.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the U.S. Government.
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THE NATIONAL ACADEMIES
National Academy of Sciences
National Academy of Engineering
Institute of Medicine
National Research Council
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. Bruce M. 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 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 programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. A. Wulf is president of the National Academy of Engineering.
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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 engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. Wm. A. Wulf are chairman and vice chairman, respectively, of the National Research Council.
COMMITTEE ON RIPARIAN ZONE FUNCTIONING AND STRATEGIES FOR MANAGEMENT
MARK M. BRINSON, Chair,
East Carolina University, Greenville, North Carolina
LAWRENCE J. MacDONNELL, Vice Chair,
Porzak, Browning & Bushong, Boulder, Colorado
DOUGLAS J. AUSTEN,
Illinois Department of Natural Resources, Springfield
ROBERT L. BESCHTA,
Oregon State University, Corvallis
THEO A. DILLAHA,
Virginia Polytechnic Institute and State University, Blacksburg
DEBRA L. DONAHUE,
University of Wyoming, Laramie
STANLEY V. GREGORY,
Oregon State University, Corvallis
JUDSON W. HARVEY,
U.S. Geological Survey, Reston, Virginia
MANUEL C. MOLLES, Jr.,
University of New Mexico, Albuquerque
ELIZABETH I. ROGERS,
White Water Associates, Inc., Amasa, Michigan
JACK A. STANFORD,
University of Montana, Polson
LAURA J. EHLERS, Study Director
ANITA A. HALL, Senior Project Assistant
WATER SCIENCE AND TECHNOLOGY BOARD
RICHARD G. LUTHY, Chair,
Stanford University, Stanford, California
JOAN B. ROSE, Vice Chair,
University of South Florida, St. Petersburg
RICHELLE M. ALLEN-KING,
Washington State University, Pullman
GREGORY B. BAECHER,
University of Maryland, College Park
KENNETH R. BRADBURY,
Wisconsin Geological and Natural History Survey, Madison
CH2M Hill, Boston, Massachusetts
University of Minnesota, Minneapolis
Pacific Institute for Studies in Development, Environment, and Security, Oakland, California
STEVEN P. GLOSS,
U.S. Geological Survey, Flagstaff, Arizona
JOHN LETEY, Jr.,
University of California, Riverside
DIANE M. McKNIGHT,
University of Colorado, Boulder
CHRISTINE L. MOE,
Emory University, Atlanta, Georgia
RUTHERFORD H. PLATT,
University of Massachusetts, Amherst
JERALD L. SCHNOOR,
University of Iowa, Iowa City
Virginia Polytechnic Institute and State University, Blacksburg
R. RHODES TRUSSELL,
Montgomery Watson, Pasadena, California
STEPHEN D. PARKER, Director
LAURA J. EHLERS, Senior Staff Officer
JEFFREY W. JACOBS, Senior Staff Officer
WILLIAM S. LOGAN, Senior Staff Officer
MARK C. GIBSON, Staff Officer
M. JEANNE AQUILINO, Administrative Associate
ELLEN A. DE GUZMAN, Research Associate
PATRICIA JONES KERSHAW, Study/Research Associate
ANITA A. HALL, Administrative Assistant
ANIKE L. JOHNSON, Project Assistant
JON Q. SANDERS, Project Assistant
BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
GORDON ORIANS, Chair,
University of Washington, Seattle
JOHN DOULL, Vice Chair,
University of Kansas Medical Center, Kansas City
University of Texas, Austin
INGRID C. BURKE,
Colorado State University, Fort Collins
Johns Hopkins University, Baltimore, Maryland
WILLIAM L. CHAMEIDES,
Georgia Institute of Technology, Atlanta
CHRISTOPHER B. FIELD,
Carnegie Institute of Washington, Stanford, California
J. PAUL GILMAN,
Celera Genomics, Rockville, Maryland
DANIEL S. GREENBAUM,
Health Effects Institute, Cambridge, Massachusetts
BRUCE D. HAMMOCK,
University of California, Davis
Lovelace Respiratory Research Institute, Albuquerque, New Mexico
American Chemistry Council, Arlington, Virginia
Michigan State University, East Lansing
JAMES H. JOHNSON,
Howard University, Washington, D.C.
JAMES F. KITCHELL,
University of Wisconsin, Madison
University of Ottawa, Ottawa, Ontario
JAMES A. MACMAHON,
Utah State University, Logan
WILLEM F. PASSCHIER,
Health Council of the Netherlands, The Hague
Pace University School of Law, White Plains, New York
LOUISE M. RYAN,
Harvard University, Boston, Massachusetts
University of California, Berkeley
Natural Resources Defense Council, New York, New York
JAMES J. REISA, Director
DAVID J. POLICANSKY, Associate Director and Senior Program Director for Applied Ecology
RAYMOND A. WASSEL, Senior Program Director for Environmental Sciences and Engineering
KULBIR BAKSHI, Program Director for the Committee on Toxicology
ROBERTA M. WEDGE, Program Director for Risk Analysis
K. JOHN HOLMES, Senior Staff Officer
RUTH E. CROSSGROVE, Managing Editor
Lands next to water are fundamental to the livelihood of many species of plants and animals, including humans. Birds and other wildlife aggregate in riparian areas, often in great abundance. At the same time, society values riparian areas for production of food and fiber, access to transportation, opportunities for recreation, and natural scenic beauty. This report examines the structure and functioning of riparian areas, how they have been altered by human activity, their legal status, and their potential for management and restoration.
The committee assembled to write this report represents diverse backgrounds, among them various aspects of ecology, hydrology, environmental engineering, and water resources law and policy. Further, committee members come from different geographical areas and have had varied research and management experiences. The group met five times over a period of two years.
This study is an outgrowth of the National Research Council (NRC) report Wetlands: Characteristics and Boundaries. The 1995 study recognized that floodplains of rivers in very different climates had similar functions, but that only those in humid climates were wet enough to be designated as wetlands. It became apparent that wetlands were being defined by the presence of a minimum amount of soil saturation necessary to select for plants capable of tolerating oxygen deficiency in the rooting zone—a definition that excludes many riparian areas. Riparian areas on the other hand are primarily defined by their position as those lands bordering streams, rivers, and lakes. (And there is no justifiable reason to exclude shorelines of estuaries and marine coasts.) Although wetlands and riparian areas provide many of the same environmental functions, the differences between their definitions are reflected in vastly different levels of protection.
The current legal and regulatory status of riparian areas is amazingly diverse. There are significant differences in how riparian areas are treated depending on whether they are publicly or privately owned; whether they are under federal, state, or local jurisdiction; and whether the land is agricultural, silvicultural, rangeland, or urban. This is in stark contrast to the situation with wetlands where a federal presence has provided some stability to local practices for more than two decades.
Largely because of the geographic diversity of riparian areas, it is unrealistic to expect that one approach for restoration, or a handful of legal strategies, can resolve the multitude of problems and issues that face riparian areas. In spite of that, many of the recommendations in this report are derived from the fundamental principle that riparian areas are driven by hydrology, and that hydrologic alterations are among the most pernicious impacts.
For a variety of reasons, the committee did not specifically treat economic issues, although several guest speakers provided economic perspectives and analyses. The costs and benefits of managing and protecting riparian areas weighed heavily in our deliberations. This is especially evident in the section on legal and social issues, both inherently economic topics.
Any study of this scope should be comprehensive and regionally balanced. However, much of the imagery generated during riparian discussions at a national level had the western states as a backdrop. Further, the topics of dry-land irrigation, water law, and livestock grazing on public lands are strongly associated with the term “riparian.” Although these same topics apply in other regions of the country, they are nowhere as obvious (and in need of attention) than in the American West where so much land is held in the public trust. Where federal policies have caused problems, in most cases federal policies must be invoked to fix them.
The committee would like to thank those who participated in its deliberations. Presentations from sponsoring organizations were made by Joe Williams, John Meagher, and Steve Schmelling from the U.S. Environmental Protection Agency; Gail Mallard and Jonathan Friedman from the U.S. Geological Survey; Mitch Flanagan, Dennis Thompson, and Dave Seery from USDA Natural Resources Conservation Service; Don Prichard from the Bureau of Land Management; and Jerry Christner and Jim Sedell from the U.S. Forest Service. Invited presenters also included Anne Hairston-Strang from the Maryland Department of Natural Resources; Juliet Stromberg and Robert Ohmart from Arizona State University; Patrick McCarthy from The Nature Conservancy; David Kovacic and John Braden from the University of Illinois at Urbana; Joe Colletti from Iowa State University; Mike Dosskey from the U.S. Forest Service National Agroforestry Center; and Chuck Elliot and Dennis Peters from the U.S. Fish and Wildlife Service.
The committee was fortunate to have taken several field trips in conjunction with committee meetings. The following individuals are thanked for their partici-
pation in organizing and guiding these trips: Robert Parmenter, Cliff Dahm, and James Gosz from the University of New Mexico; Richard Schultz, Tom Isenhart, and Bill Simpkins from Iowa State University; Jerry Hatfield and Dana Dinnes of the U.S. Agricultural Research Service; Wayne Elmore of the Bureau of Land Management; Susan Holzman of the U.S. Forest Service; and John Anderson, retired.
Committee members are grateful to the leadership provided by Laura Ehlers of the National Research Council in serving as the institutional memory of the committee, organizing committee meetings, and synthesizing, coordinating, and editing the report. Anita Hall was instrumental in creating problem-free arrangements for our meetings.
More formally, the report has been reviewed by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the authors and the NRC in making the 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 reviews and draft manuscripts remain confidential to protect the integrity of the deliberative process. We thank the following individuals for their participation in the review of this report: Robert Adler, University of Utah College of Law; Paul Barten, University of Massachusetts Amherst; Nancy Grimm, Arizona State University; Clayton Marlow, Montana State University; Robert Naiman, University of Washington; Brian Richter, The Nature Conservancy; Richard Schultz, Iowa State University; and Juliet Stromberg, Arizona State University.
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 Wilford Gardner, University of California at Berkeley. Appointed by the NRC, he was 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 NRC.
Mark M. Brinson, Chair