Read Full Report

Date: March 31, 2004
Contacts: Bill Kearney, Director of Media Relations
Chris Dobbins, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <>


Flexible Approach to Columbia River Water Withdrawals
Needed to Protect Listed Salmon

WASHINGTON -- If Washington state issues additional permits for water to be diverted from the Columbia River for farm irrigation, it should do so only under the condition that withdrawals can be stopped if river flows become critically low for endangered and threatened salmon, says a new report from the National Academies' National Research Council. Salmon are at increased risk during periods of low flows and high water temperatures, conditions that are most likely to occur during the summer months when demand for water by farmers is greatest, the report says.

"Whether or not to issue additional permits is a decision to be made by the public and policy-makers, but if the withdrawals are allowed, there should be enough flexibility to halt them if river conditions become too severe for the salmon," said Ernest Smerdon, chair of the committee that wrote the report, and retired vice provost and dean, College of Engineering and Mines, University of Arizona, Tucson.

The report was requested by the Washington State Department of Ecology, which asked for an evaluation of the effects of additional water withdrawals of approximately 250,000 acre-feet to 1.3 million acre-feet per year, roughly the volume sought in currently pending applications for additional water withdrawals. An acre-foot is the quantity of irrigation water that would cover an acre to a depth of one foot -- equal to 325,851 gallons.

Over the course of the 20th century, salmon runs on the Columbia River dwindled from around 16 million per year to only 1 million per year. Their numbers have rebounded slightly in recent years, mainly because of favorable conditions in the Pacific Ocean, to which young salmon migrate before returning upstream to spawn.
The committee reviewed many competing scientific hypotheses and models that attempt to explain the effects of various environmental conditions on Columbia River salmon. There is no scientific consensus on which environmental factors pose the greatest threat to salmon, the committee said, but scientific evidence does show that when extremely low flows or excessively high water temperatures occur, pronounced changes in salmon migratory behavior and lower survival rates can be expected. Several dams on the Columbia have slowed the river's velocity and smoothed out much of its natural variability, although its water levels and velocity still fluctuate considerably on a daily, seasonal, and yearly basis, the committee said. It also emphasized that policy-makers must be willing to develop a sound, comprehensive water management plan despite the scientific uncertainties.

Because the Columbia River basin extends across seven states, many Indian reservations, and one Canadian province, the committee urged the jurisdictions involved to convene a forum for documenting and discussing the potential effects of proposed water diversions. Making decisions about diversions on a case-by-case basis without considering the basinwide cumulative effects will contribute to degraded conditions for salmon, the committee said.

Several water management approaches being considered by the state's department of ecology were reviewed by the committee. It recommended against any conversion of current water rights to so-called uninterruptible status -- an approach in which a farmer gives up rights to a certain volume of water in exchange for a guaranteed minimum level of water every year -- because this method would decrease flexibility in times of low flows or high water temperatures. On the other hand, the committee found the department's market-based proposals appealing because the trading of water rights could lessen the need for further water diversions. Regardless of the approaches it chooses, the department of ecology should adopt the principles of adaptive management, where decisions are made and adjusted based on continuous scientific experimentation and monitoring.

The study was sponsored by the Washington State Department of Ecology. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.

Copies of Managing the Columbia River: Instream Flows, Water Withdrawals, and Salmon Survival will be available later this spring from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[ This news release and report are available at ]

Division on Earth and Life Studies

Water Science and Technology Board
Board on Environmental Studies and Toxicology

Committee on Water Resources Management, Instream Flows, and
Salmon Survival in the Columbia River

Ernest T. Smerdon* (chair)
Vice Provost and Dean
College of Engineering and Mines
University of Arizona (retired)

Richard M. Adams
Department of Agricultural and Resource Economics
Oregon State University

Donald W. Chapman
Consulting Biologist
McCall, Idaho

Darrell Fontane
International School for Water Resources, and
Department of Civil Engineering
Colorado State University
Fort Collins

Albert E. Giorgi
President and Senior Fisheries Scientist
BioAnalysts Inc.
Redmond, Wash.

Helen M. Ingram
Drew, Chace, and Erin Warmington Chair in the Social Ecology of Peace and International Cooperation, and
School of Social Ecology
University of California

W. Carter Johnson
Department of Horticulture, Forestry, Landscape, and Parks
South Dakota State University

John J. Magnuson
Director Emeritus
Center for Limnology, and
Professor Emeritus
Department of Zoology
University of Wisconsin

Stuart McKenzie
U.S. Geological Survey (retired)
Gresham, Ore.

Diane M. McKnight
Department of Civil, Environmental, and Architectural Engineering
University of Colorado

Tammy J. Newcomb
Lake Huron Basin Coordinator
Michigan Department of Natural Resources

Kenneth K. Tanji
Professor Emeritus
Department of Land, Air, and Water Resources
University of California

John E. Thorson
Attorney at Law
Oakland, Calif.


Jeffrey W. Jacobs
Study Director

* Member, National Academy of Engineering