Publications

Hydrogeologic information for western Oregon was compiled to aid the U.S. Environmental Protection Agency in evaluating proposals for underground injection of waste fluid. Geologic formations were grouped into seven aquifer units according to hydraulic and geologic similarities. The bedrock aquifer units in the Klamath Mountains, Coast Range, and Western Cascade Range all have low permeabilities a

Over the last 20 years there has been a shift from dryland to irrigated agriculture in parts of Gilliam, Morrow, and Umatilla Counties in northeastern Oregon. Some irrigation water used in this area obtained from surface sources, but a significant amount is obtained from wells. The principal aquifer in the area is the Columbia River Basalt Group. Wells in the basalt are commonly drilled to depths

Water-surface profiles were computed for a 19.4-mile reach of Calapooya Creek in Douglas County, Oregon. The data will enable the county to evaluate flood hazards in the floodprone areas in the reach. Profiles for floods having recurrence intervals of 2, 10, 50, 100, and 500 years are shown in graphic and tabular form. A floodway, allowing encroachment of the 100-year floods, was designed with a m

A method for estimating the magnitude and frequency of floods is presented for unregulated streams in eastern Oregon. Equations relating flood magnitude to basin characteristics were developed for exceedance probabilities of 0.5 to 0.01 (2- to 100-year recurrence intervals). Separate equations are presented for four regions: Southeast, Northeast, North Central, and Eastern Cascades. Also presented

Very little information is available concerning acoustic velocity meter (AVM) operation, performance, and limitations. This report provides a better understanding about the application of AVM instrumentation to streamflow measurment. Operational U.S. Geological Survey systems have proven that AVM equipment is accurate and dependable. AVM equipment has no practical upper limit of measureable veloci

The Water Resources Division investigates and reports on the occurrence, quantity, quality, distribution, and movement of surface and underground water. Work of the Division is described in detail later in this report.

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 July and August 1978, the U.S. Geological Survey, in cooperation with the Oregon Department of Enviromental Quality, made three intensive river-quality dissolved-oxygen studies in the upper Willamette River basin. Two studies were made on the upper Willamette River and one was made on the Santiam River, a Willamette River tributary. Nitrification, occurring in both the upper Willamette and

No abstract available.

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.

No abstract available.

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