Publications

The use of groundwater in Oregon is expected to increase owing to continued population growth and to surface water supplies that are inadequate to meet present or future demand. The major groundwater issues in Oregon are: conjunctive use of surface and groundwater; contamination from hazardous wastes, leakage from underground gasoline and diesel tanks, naturally occurring brackish water, and high

No abstract available.

A one-dimensional, unsteady-state, open-channel model was used to analytically reproduce three lahar events. Factors contributing to the success of the modeling were: (1) the lahars were confined to a channel, (2) channel roughness was defined by field information, and (3) the volume of the flow remained relatively unchanged for the duration of the peak. Manning 's 'n ' values used in computing co

A one dimensional, unsteady-state temperature model using the equilibrium temperature approach (with air temperature used to estimate equilibrium temperature) is used to evaluate the effects of two Army Corps of Engineers dams and resulting reservoirs on the McKenzie River, from Delta Park (River Kilometer 99.9) to Leaburg Dam (River Kilometer 62.4). Both Corps of Engineers projects are on tributa

The Columbia Plateau is underlain by massive basalt flows, with a composite thickness of about 10,000 ft. Structural features within the study area include a series of anticline-syncline pairs. The main avenues of groundwater movement in the basalt are the interflow zone between basalt flows. Individual interflow zones may be rather extensive in the lateral direction and are largely isolated from

During the period October 1978 to September 1983, the U.S. Geological Survey, in cooperation with the City of Portland (Oregon) Water Bureau, conducted a study in the Bull Run River basin to define the hydrologic characteristics of the basin, and to examine relations between basin characteristics (both natural and man-made) and stream water quality and quantity within the basin. Hydrologically, th

Stormwater runoff for the period December 1979 to May 1981, at 13 sites (12 basins) in the vicinity of Salem, Oregon, was sampled and analyzed for water quality. Constituent concentrations for urban storm water were relatively small when compared to samples from Portland and Medford, Oregon and to samples from Denver, Colorado. The data indicated that levels of suspended sediment, ultimate CBOD (c

A recent evaluation of groundwater and material in the blockage impounding Castle Lake shows that the blockage is potentially unstable against failure from piping due to heave and internal erosion when groundwater levels are seasonally high. There is also a remote possibility that a 6.8 or greater magnitude earthquake could occur in the Castle Lake area when groundwater levels are critically high.

Drought conditions prevailed throughout the States of California , Nevada, Idaho, Oregon, and Washington during the summer of 1987. Streamflows were the lowest since the drought of 1977. Many streams had less discharge in August-September 1987 than in August-September of 1977. At some sites flows for July, August, and September were the minimum ever recorded for those months. The reason for the lo

Above average precipitation and runoff between 1980 and 1985 have raised the water-surface elevation of Harney, Mud, and Malheur Lakes in eastern Oregon to the highest levels recorded and have caused mixing and interflow of water among the three lakes. A 50% increase in specific conductance throughout Malheur Lake from 1984 to 1985 resulted from an increase in sodium and chloride concentrations, p

No abstract available.

Groundwater pumpage was estimated for 1984 for an area of about 8,000 sq mi in north-central Oregon. Pumpage data were collected from irrigation, industrial and public supply users and analyzed as part of the Columbia Plateau Regional Aquifer System Analysis (RASA) study. Groundwater is pumped from Tertiary basalts and interflow material of the Columbia River Basalt Group and the overlying Tertiar