Water Availability and Use

Island County consists of two major islands, Whidbey and Camano, and lies in northern Puget Sound, north of Seattle. Whidbey Island has an area of about 165 square miles and Camano Island an area of about 45 square miles, for a total area of about 210 square miles. Ground water is the primary source of water on the islands, and the ground-water system is fairly well understood, due in part to...

The quantity and quality of instream habitat is one of many factors affecting aquatic organisms such as anadromous and non-anadromous salmonids. The measurement and assessment of instream habitat has been the focus of many habitat monitoring and restoration projects throughout the State of Washington. On-the-ground habitat monitoring is extremely important for specific variables and specific...

In recent years, increased use of ground- and surface-water supplies in watersheds of Washington State has created concern that insufficient in-stream flows remain for fish and other users. In response, the Washington State legislature passed the Watershed Management Act of 1998 (ESHB 2514; see also Ch.90.82 RCW - Watershed Planning), which encourages and provides some funding for local watershed...

More than 70 percent of the population of Washington and Oregon resides in the Puget Sound-Willamette Trough, which stretches north-south on the western side of the Cascade Range. The area is one of the principal regional ground-water systems in the Nation, but little is known about the quantity and quality of the ground water, the regional flow system, or the interaction of the system with...

Have increased demands for Washington State's ground water and surface water left sufficient stream flows for fish and other uses? To find out, the state's Watershed Management Act of 1998 (ESHB 2514) confers on local people the responsibility for conducting local watershed planning. The Elwha-Morse Watershed area was formed out of the western part of Water Resources Inventory Area 18 (WRIA 18) in...

The rapid growth of population in the Tacoma-Puyallup area in Pierce County has placed increasing demands on the ground-water resource. Most domestic water needs are met by wells completed in the several hundred feet of glacial deposits that underlie the area, and about 9,000 persons are served by a single spring on the southwestern side of Puyallup. Most of the population relies on individual...

Under Washington regulations, bridges, culverts, and other stream-crossing structures need to be designed with fish passage in mind. For culverts, maximum flows cannot exceed a 10-percent exceedance probability flow (the flow that is equalled or exceeded 10 percent of the time) when fish are migrating upstream. To help the Washington Department of Natural Resources manage its culverts at more than...