USGS Washington Water Science Center
|U.S. Department of the Interior
U.S. Geological Survey
Release: February 23, 2006
John J. Vaccaro,
[Note: The report can be viewed on the Web at http://pubs.usgs.gov/sir/2007/5007 .]
Irrigation of croplands in the Yakima River Basin has increased ground-water recharge by about 30 percent since before development began in the basin, according to a new report published today by the U.S. Geological Survey (USGS).
Produced in cooperation with the Bureau of Reclamation, the Washington State Department of Ecology, and the Yakama Nation, the report provides estimates of average annual recharge for predevelopment and current conditions. It is the fifth in a series of reports from an eight-year cooperative study of the ground-water resources of the Yakima River Basin.
Scientists estimated recharge to the Yakima River Basin aquifer system for predevelopment (natural) and current (1995-2004) land-use and land-cover conditions, using two different computer models.
For predevelopment conditions, the average annual recharge was estimated at about 11.9 inches, or about 3.9 million acre-feet, for the entire basin. Most of the recharge occurs in the uplands, where recharge is as high as 34 inches. Only about 0.4 inches occurs in the semiarid to arid lowland areas.
For current conditions, the average annual recharge was estimated at about 15.6 inches, or about 5.3 million acre-feet for the entire basin. The increase in recharge from predevelopment conditions is the result of irrigation water not taken up by crops. In some areas, for example, the annual quantity of irrigation was more than five times the annual precipitation.
"These estimates provide a spatial distribution of recharge used in computer models we are developing to better understand the ground-water flow system of the Yakima River Basin and to test water management strategies," said John Vaccaro, USGS hydrologist and lead author of the report.
The report, "Estimates of ground-water recharge to the Yakima River Basin Aquifer System, Washington, for predevelopment and current land-use and land-cover conditions," by J.J. Vaccaro and T.D. Olsen, is published as U.S. Geological Survey Scientific Investigations Report 2007-5007. The report can be viewed on the Web at http://pubs.usgs.gov/sir/2007/5007//. A related report, "A deep percolation model for estimating ground-water recharge: Documentation of modules for the Modular Modeling System of the U.S. Geological Survey," by J.J. Vaccaro, is published as U.S. Geological Survey Scientific Investigations Report 2006-5318 and can be viewed on the Web at http://pubs.usgs.gov/sir/2006/5318/. Copies can be purchased from the U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225-0286, telephone 303-202-4200.
USGS provides science for a changing world. For more information visit https://www.usgs.gov/ .