The Columbia Plateau Regional Aquifer System (CPRAS) covers over 50,000 square miles of eastern Oregon and Washington and western Idaho. The primary aquifers are basalts of the Columbia River Basalt Group and overlying basin-fill sediments. Ground-water availability issues in the basin include: 1) widespread water-level declines caused by pumping, 2) reduction in base flow to rivers and associated effects on temperature and water quality, and 3) effects of global climate change on recharge, base flow, and ground-water availability.
The USGS has begun a study of the Columbia Plateau Regional Aquifer System with the broad goals of: 1) characterizing the hydrologic status of the system, 2) identifying trends in ground-water storage and use, and 3) quantifying ground-water availability.
This project started in October 2007 and is scheduled to be completed in four years. More information on the research questions being addressed by the study and major elements of the approach can be found by following the links on the left. As the project progresses, more information, including data and links to publications will be posted on this site.