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Research about King County, Washington

Source-linked reports with geographic coverage including King County, Washington.

24 records · Page 2Linked to original sources
USGS1968

Water resources of King County, Washington

Although the total supply of water in King County is large, water problems are inevitable because of the large and rapidly expanding population. The county contains a third of the 3 million people in Washington, most of the population being concentrated in the Seattle metropolitan area. King County includes parts of two major physiographic features: the western area is part of the Puget Sound Lowland, and the eastern area is part of the Cascade Range. In these two areas, the terrain, weather, and natural resources (including water) contrast markedly. Average annual precipitation in the county is about 80 inches, ranging from about 30 inches near Puget Sound to more than 150 inches in parts of the Cascades. Annual evapotranspiration is estimated to range from 15 to 24 inches. Average annual runoff ranges from about 15 inches in the lowlands to more than 100 inches in the mountains. Most of the streamflow is in the major basins of the county--the Green-Duwamish, Lake Washington, and Snoqualmie basins. The largest of these is the Snoqualmie River basin (693 square miles), where average annual runoff during the period 1931-60 was about 79 inches. During the same period, annual runoff in the Lake Washington basin ( 607 square miles) averaged about 32 inches, and in the Green-Duwamish River basin (483 square miles), about 46 inches. Seasonal runoff is generally characterized by several high-flow periods in the winter, medium flows in the spring, and sustained low flows in the summer and fall. When floods occur in the county they come almost exclusively between October and March. The threat of flood damage is greatest on the flood plaits of the larger rivers, but in the Green-Duwamish Valley the threat was greatly reduced with the completion of Howard A. Hanson Dam in 1962. In the Snoqualmie River basin, where no such dam exists, the potential damage from a major flood increases each year as additional land is developed in the Snoqualmie Valley. Only moderate amounts of sediment are transported by most streams in the county, except during short periods of heavy rain in the winter. The temperature and chemical quality of surface waters are well suited to the requirements of fisheries and for municipal, industrial, and domestic supplies. Little treatment is needed for most uses of surface water, except where the water is subject to pollution. Most recoverable ground water in the county occurs in the Puget Sound Lowland, where great volumes of unconsolidated sedimentary deposits were left by the continental glaciers of the Pleistocene Epoch. Bedrock, most of which is in the Cascade Range, contains very little ground water. Numerous springs, largely undeveloped, occur in several parts of the county. Most of the ground water is of good to excellent quality except for excessive iron, which in some places may require treatment of the water before it is suitable for domestic or industrial use. Excluding water used for hydroelectric-power, recreation, and fisheries, more than 80 percent of the water used in the county is provided by municipal-supply systems. Each of the major river basins includes municipal watersheds that provide large supplies of excellent water. By the 1980's, more than 90 percent of the county's population will probably be served by the Seattle municipal supply. With full development, Seattle's water system would have a capacity sufficient to supply more than 2 million people with 300 gallons per person per day. Most industrial and commercial establishments in the county obtain water from public supply systems. The most serious water problem in the county at present (1965) is the threat of pollution in the densely populated areas. The immediate threat in the Seattle area is being reduced by the sewage-treatment program of the Municipality of Metropolitan Seattle, which will eliminate the discharge of waste into Lake Washington. Expected increases in population and industry will introduce new problems that will require additional planning to assure adequate water quality for fisheries, recreation, and other uses.

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USGS1966

Clinostomum marginatum in steelhead trout ( Salmo gairdneri ) and cutthroat trout ( Salmo clarki ) in a western Washington lake

Clinostomum marginatum (Trematoda: Clinostomatidae), the yellow grub parasite, was recorded in epizootic proportions from Lynch Lake, King County, Washington, in 1961 and 1962. The parasite larvae occurred principally in steelhead trout (Salmo gairdneri); cutthroat trout (S. clarki) were infected to a relatively minor degree. Fish and snail host populations were destroyed by rotenone and copper sulfate treatments.

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USGS1963

Geology and ground-water resources of northwestern King County, Washington

King County, in the west-central part of the State of Washington, includes about 2,135 square miles. The eastern part of the county lies in the Sierra-Cascade Mountains province and the remainder is in the Puget Trough of the Pacific Border province. The area covered by the present investigation is almost entirely within the Puget Trough and includes about 450 square miles.

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USGS1955

Records of wells, water levels, and quality of ground water in the Sammamish Lake area, King County, Washington

This report, one of a series on the ground-water resources of the State of Washington, contains well records and other data collected during the course of an investigation in the Sammamish Lake area immediately east of Seattle, King County, Washington. Most of these investigations are conducted in cooperation with the State of Washington, Department of Conservation and Development, Division of Water Resources. However, a few investigations, including the one in the Sammamish Lake area, have been made entirely with Federal funds. A similar investigation is now being made in the area to the west, including the city of Seattle and metropolitan areas to the north and south. It is planned that results of teh two investigations will be combined into a single comprehencive report. In order that the data collected can be made available sooner, this report as been prepared with only a brief explanatory and descriptive text.

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