OLYMPIA - The future water requirements of the Columbia Basin communities, farms and fish are the focus of a draft report soon to be released 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 with assistance from Washington State University and Washington Department of Fish and Wildlife (WDFW).
A long-term supply and demand forecast is required by law every five years and is due to the Legislature on Nov. 15. The public comment period will run from the publication of the draft on Sept. 6 until Oct. 7.
A series of public workshops is scheduled for September in Richland, Wenatchee and Spokane to share the report and to garner feedback about the preliminary findings. An online workshop will be available in late September for those who cannot attend a workshop in person. The Richland workshop will be held Wednesday, Sept. 7, from 3 to 7 p.m. in the Tri-Cities West Building in Richland.
"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," said Derek Sandison, who heads Ecology's Office of the Columbia River.
Data collected for the 2011 report employs the latest modeling tools and incorporates factors such as climate change and 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... 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 also evaluates fish stocks and flow and habitat conditions for critical rivers throughout Eastern Washington through an "instream atlas" developed by WDFW. The atlas will help agencies "target water supply improvement projects in locations where fish need it most," said Teresa Scott, Water Resource Policy Coordinator for WDFW.
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 http://www.ecy.wa.gov/programs/wr/cwp/wsu_supply-demand.html.