2006 Columbia River Legislative Report - Columbia River Water Supply Inventory and Long-Term Water Supply and Demand Forecast

Columbia River Legislative Report

On Feb. 14, 2006, the Legislature passed a bill creating a new framework for managing water resources in the Columbia River basin.  The legislation requires the Washington State Department of Ecology to complete an inventory of the Columbia River’s water supply and to forecast future water supply and demand requirements.

The report consists of two parts.  The first, the Columbia River Water Supply Inventory, lists the conservation and storage projects available for acquiring water for instream uses like ensuring adequate streamflows for fish and out-of-stream uses such as for farming and drinking water.  The Columbia River Water Management Program will use this report to evaluate and rank projects for funding.  The Supply Inventory Report will be updated annually.  The second portion, the Long-Term Water Supply and Demand Forecast, looks at increased water demands due to population growth and the effect crop changes and global warming may have on water supply and demand.

As required by the legislation, Ecology will update the water supply inventory annually and the long-term water supply and demand forecast every five years.  These reports will help the State to manage the river more efficiently.

View individual chapters of the document:


Ecology selected a consultant group led by Golder Associates in conjunction with Anchor Environmental and Adolfson Associates to assist in the preparation of the report.  The State Conservation Commission and local conservation districts were also involved, all with the goal of developing a comprehensive database of all known conservation project opportunities in the greater Columbia basin in Eastern Washington.  The database includes information on each project, the amount of water that can be conserved, the cost of the project and other relevant information.

Additionally, Ecology coordinated with Washington State University (WSU) to provide expertise on long-term crop demand forecasting for the Columbia River basin.  The evaluation provided by WSU was incorporated by Golder into the framework of the larger report. A draft report was made available for public comment from October 15 to November 8, 2006.  Open houses were held during the public comment period in Colville, Kennewick, Moses Lake and Wenatchee.  The final report was issued on November 15, 2006.