USGS Washington Water Science Center
|U.S. Department of the Interior
U.S. Geological Survey
Release: March 21, 2011
[Editors: A video podcast about the project is on-line at http://gallery.usgs.gov/videos/350 .]
TACOMA, Wash. -- Scientists have developed a three-dimensional depiction of the geology of the Columbia Plateau that will aid water resource managers coping with declining groundwater levels, development, and climate change in the region, according to a report published by the U.S. Geological Survey.
Groundwater is a critical resource for the nearly 1.3 million people in the region, as well as providing irrigation water for the region’s estimated $6 billion-per-year agriculture. A recent USGS study showed that groundwater levels of the Columbia Plateau have declined over the past 25 years in about 80 percent of the nearly 500 wells measured in the study.
To help resource managers in the region, in 2007, the USGS Groundwater Resources Program began a study of the Columbia Plateau Regional Aquifer System to answer key questions about widespread water-level declines, reductions in groundwater flow into rivers, and the as-yet unknown effects of a changing climate on groundwater resources.
As part of the study, USGS scientists built a three-dimensional geologic model--a computer model of geologic units--to define the overall aquifer system in the Columbia Plateau, to be used in a regional numerical model of groundwater flow. The geologic model covers about 53,000 square miles of the Columbia Plateau in Washington, Oregon, and Idaho.
"The geologic model of the Columbia Plateau gives us a more complete picture of the shape and volume of the regional aquifer system," said Erick Burns, a USGS scientist working on the study. "This information will be used to build a groundwater flow model to help water resource managers who are working on the issue of declining groundwater levels in the region, and coping with changing development and climate conditions."
In addition to defining the geology of the aquifer system, USGS scientists also are documenting hydrologic changes and developing a "water budget" for the system. This information will help scientists build a groundwater-flow simulation model that managers can use to test ways of managing the region’s groundwater under different development and climate conditions.
This study and related groundwater availability studies are being conducted nationally by the USGS through the Groundwater Resources Program. Information about the Groundwater Resources Program is available online at http://water.usgs.gov/ogw/gwrp/activities/regional.html.
The report, "Three-Dimensional Model of the Geologic Framework for the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington," by E.R. Burns, D.S. Morgan, R.S. Peavler, and S.C. Kahle, is published as U.S. Geological Survey Scientific Investigations Report 2010-5246 and is available on the Web at http://pubs.usgs.gov/sir/2010/5246/ . The project Web page is http://wa.water.usgs.gov/projects/cpgw/ . Additionally, a podcast about this work is available at http://gallery.usgs.gov/videos/350 .