Publications

During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream

During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream

No abstract available.

Appraisals of the resources of selected management areas in eastern Oregon are being made by the U.S. Bureau of Land Mangement. To provide needed hydrologic information, the Bureau of Land Management requested the U.S. Geological Survey to inventory ground-water data for the Riley and Andrews Resource Areas. The inventory included field location of selected wells and springs; measurement of ground

A series of equations was developed to provide a better method of determining flood frequencies in the Portland-Vancouver urban area than is now available. The resulting regression equations can be used to compute peak discharge and storm runoff with a standard error of estimate of approximately 30 percent. Basins used to define the regression equations ranged in size from 0.2 to 26 square miles.

For nearly half a century the Willamette River in Oregon experienced severe dissolved-oxygen problems related to large loads of organically rich waste waters from industries and municipalities. Since the mid-1950 's dissolved oxygen quality has gradually improved owing to low-flow augmentation, the achievement of basinwide secondary treatment, and the use of other waste-management practices. As a

No abstract available.

The water supply for the Reedsport area is obtained from Clear Lake, a 310-acre coastal lake that contains 16, 600 acre-feet of water at full-pool. The lake receives about 6,000 acre-feet of water annually from runoff and direct precipitation, and it loses about 600 acre-feet by evaporation. The 2,100 acre-feet diverted annually for public supply is about two-thirds of the ' usable storage capacit

On May 25-26, May 30-June 2, and June 12-13, 1980, strong, high-altitude winds from the north occurred during periods of volcanic-ash eruption at Mount St. Helens in southwestern Washington. As a result, ash fell in the Bull Run watershed, Oregon, some 50 miles to the south, the principal water-supply source for the Portland area. Samples from precipitation collectors and from stream sites in the

Water-quality data identify surface-water-quality problems in Bear Creek basin, Jackson County, Oreg., where possible, their causes or sources. Irrigation and return-flow data show pastures are sources of fecal coliform and fecal streptococci bacteria and sinks for suspended sediment and nitrite-plus-nitrate nitrogen. Bear Creek and its tributaries have dissolved oxygen and pH values that do not m

The Myrtle Creek-Glendale area covers about 400 mi2 (1,000 km2 in Douglas County in southwestern Oregon.  Although the geologic formations of the area have low permeabilities and generally yield small amounts of water to wells, ground water is the chief source of water for domestic usse in rural parts of the area not served by public supplies.  A well capable of yielding 5 to 10 gal/min (0.3 to 0.

The Pacific Northwest Region's ground-water reservoirs are capable of providing large additional fresh-water supplies; these reservoirs become more important as undeveloped surface-storage sites and unapportioned surface-water supplies dwindle. Withdrawals of fresh water from all surface and underground sources are increasing; they may rise from the rate of 30 billion gallons per day in 1970 to ab