USGS - Science for a Changing World USGS graphic link to National USGS home page

U.S. GEOLOGICAL SURVEY
Water-Resources Investigations Report 03-4128

Water Resources of the Ground-Water System in the Unconsolidated Deposits of the Colville River Watershed, Stevens County, Washington

Prepared in cooperation with
COLVILLE RIVER WATERSHED PLANNING TEAM FOR THE 2000-2004 WRIA 59 COLVILLE RIVER WATERSHED PLANNING PROJECT

By Sue C. Kahle, Claire I. Longpré, Raymond R. Smith, Steve S. Sumioka, Anni M. Watkins, and David L. Kresch

ABSTRACT

A study of the water resources of the ground-water system in the unconsolidated deposits of the Colville River Watershed provided the Colville River Watershed Planning Team with an assessment of the hydrogeologic framework, preliminary determinations of how the shallow and deeper parts of the ground-water system interact with each other and the surface-water system, descriptions of water-quantity characteristics including water-use estimates and an estimated water budget for the watershed, and an assessment of further data needs. The 1,007-square-mile watershed, located in Stevens County in northeastern Washington, is closed to further surface-water appropriations throughout most of the basin during most seasons. The information provided by this study will assist local watershed planners in assessing the status of water resources within the Colville River Watershed (Water Resources Inventory Area 59).

The hydrogeologic framework consists of glacial and alluvial deposits that overlie bedrock and are more than 700 feet thick in places. Twenty-six hydrogeologic sections were constructed, using a map of the surficial geology and drillers' logs for more than 350 wells. Seven hydrogeologic units were delineated: the Upper outwash aquifer, the Till confining unit, the Older outwash aquifer, the Colville Valley confining unit, the Lower aquifer, the Lower confining unit, and Bedrock.

Synoptic stream discharge measurements made in September 2001 identified gaining and losing reaches over the unconsolidated valley deposits. During the September measurement period, the Colville River gained flow from the shallow ground-water system near its headwaters to the town of Valley and lost flow to the shallow ground-water system from Valley to Chewelah. Downstream from Chewelah, the river generally lost flow, but the amounts lost were small and within measurement error. Ground-water levels indicate that the Lower aquifer and the shallow ground-water system may act as fairly independent systems. The presence of flowing wells completed in the Lower aquifer indicates upward head gradients along much of the Colville Valley floor.

Total surface- and ground-water withdrawals during 2001 were estimated to be 9,340 million gallons. Water use for 2001, as a percentage of the total, was 75.3 percent for irrigation, 16.3 percent for public supply, 6.5 percent for private wells, and about 1 percent each for industrial and livestock use. An approximate water budget for a typical year in the Colville River Watershed shows that 27 inches of precipitation are balanced by 4.2 inches of streamflow discharge from the basin, 0.3 inch of ground-water discharge from the basin, and 22.5 inches of evapotranspiration.

CONTENTS

Abstract
Introduction
Study Methods
Hydrogeologic Framework
Ground- and Surface-Water Interactions
Water Quality
Additional Data Needs
Summary and Conclusions
Selected References
Appendix 1

This report is available online in Portable Document Format (PDF). If you do not have the Adobe Acrobat PDF Reader, it is available for free download from Adobe Systems Incorporated.

Download the report (PDF, 4.8 MB)

Select Plate 1 (PDF, 8 MB) to view or print.

Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 5.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

Send questions or comments about this report to the author, Sue C. Kahle, (253) 428-3600 ext. 2616.

For more information about USGS activities in Washington, visit the USGS Washington District home page.

Bobby Approved Valid HTML 4.01!

FirstGov button  Take Pride in America button