Forecast on Columbia Basin Long-Term Water Needs Focus of Workshops

OLYMPIA, Wash. – How much water will be needed to support communities, farms and fish in the Columbia Basin and where it will come from is the focus of a near-final report from the Washington Department of Ecology’s Office of Columbia River.

“The Columbia River Basin Long-Term Water Supply and Demand Forecast” is being developed by Ecology with assistance from Washington State University and Washington Department of Fish and Wildlife. A long-term supply and demand forecast is produced every five years, and is due to the Legislature on Nov. 15, 2011.

A series of public workshops is scheduled for Sept. 7, 8, and 9, 2011, in Richland, Wenatchee and Spokane to share particulars of the report and to garner feedback about the preliminary findings. An online version of a workshop will be available in late September for those who cannot attend a workshop in person.

The workshops will be held:

  • Wednesday, Sept. 7, from 3 to 7 p.m., Tri-Cities West Building Room 131, WSU Tri-Cities, 2710 Crimson Way, Richland
  • Thursday, Sept. 8, from 1 to 5 p.m., WSU Tree Fruit Research and Extension Center, Overley Laboratory Building, 1100 N. Western Ave., Wenatchee
  • Friday, Sept. 9, from 9 a.m. to 1 p.m., WSU Spokane County Extension Office conference rooms B and C, 222 N. Havana, Spokane

“For the first time, we’ll have a comprehensive evaluation of what our water needs will be in the Columbia Basin,” said Derek Sandison, who heads Ecology’s Office of the Columbia River. “This report provides a blueprint for how we invest in water supply projects. It will help tell us where and when more water is needed in Eastern Washington.”

Data collected for the 2011 report employs the latest modeling tools and incorporates factors such as climate change and regional and global economic conditions into forecast calculations. The report also reflects input directly from water users in the basin.

“The report summarizes the likely changes in supply and demand over the next 20 years. Whether your interest is on changes to the Columbia River or its tributaries, inside Washington or in other states and British Columbia, Canada, this report has information that will help you make better water planning decisions,” said Michael Barber, lead scientist and director of WSU’s State of Washington Water Research Center.

The Columbia River Basin is particularly sensitive to small changes in overall temperatures. Reduced snowfall and earlier snowmelt are predicted to influence surface water flows. The report incorporates climate change impacts on future water supplies and demands.

The report also evaluates stream conditions for critical rivers throughout Eastern Washington through a “Columbia River Instream Atlas” developed by the Washington State Department of Fish and Wildlife.

“The Instream Atlas evaluates fish stocks and flow and habitat conditions in eight fish critical basins. It will help the Office of Columbia River and other funding agencies target water supply improvement projects in locations where fish need it most,” said Teresa Scott, Water Resource Policy Coordinator for Department of Fish and Wildlife.

Agriculture is the largest single user of water in Eastern Washington. The combined influences of climate change, economic trends and population growth will result in an increase in the amount of water needed for agricultural irrigation.

The report also predicts that by 2030, diversions for cities and communities in Eastern Washington will increase by approximately 24 percent or an additional 109,000 acre-feet per year, based on expected population growths.

Hydropower use in Eastern Washington is expected to remain fairly stable over the next 20 years, with increases in demand being met through conservation projects and power from other sources.

More information on the forecast is available at