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...

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...

A method for estimating the magnitude and frequency of floods is presented for unregulated streams in western 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: Coast, Willamette, Rogue-Umpqua, and High Cascades. Also...

A synoptic approach has been devised to delineate the relationships that exist' between physiographic factors, land-use activities, and resultant erosional problems. The approach involves the development of an erosional-depositional province map and a numerical impact matrix for rating the potential for erosional problems. The province map is prepared by collating data on the natural...

The rock formations of the John Day Fossil Beds National Monument area are aquifers that can be expected to yield less than 10 gallons of water per minute to wells. The most permeable of the geologic units is the alluvium that occurs at low elevations along the John Day River and most of the smaller streams. Wells in the alluvial deposits can be expected to yield adequate water supplies...

In 1978, data were collected for identification and quantification of benthic invertebrates, periphyton, and bottom material and their trace-metals concentrations from three sites in Salmon Creek basin, Wash. Metal analyses included arsenic, cadmium, chromium, copper, lead, zinc, selenium, and mercury. Physical data collected included water temperature, dissolved oxygen, pH, discharge...

The U.S. Geological Survey collected water-quality data in five Oregon stream basins during summer low-flow conditions in 1977 and 1978. During the two sampling periods, a total of 18 different sites were sampled. Several sites were sampled twice in 1977, and some sites were sampled in both 1977 and 1978. Included in the sampling were diel trace of dissolved oxygen, temperature, specific

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...

Ground-water data for the Baker County-northern Malheur area, Oregon, are tabulated for the Bureau of Land Management. The data include well and spring records, a well-location map, drillers' logs of wells, observation-well hydrographs, and chemical analyses of ground-water samples. The reported yields of wells and springs in the area ranged from less than 1 to 2,500 gallons per minute...

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...

Storm-water-quality samples were collected from four subbasins in the Bear Creek basin in southern Oregon. These subbasins vary in drainage size, channel slope, effective impervious area, and land use. Automatic waterquality samplers and precipitation and discharge gages were set up in each of the four subbasins. During the period October 1977 through May 1978, 19 sets of samples...

Surface and core sediments from Tillamook Bay, Oregon, have been analyzed to determine modern and Holocene sediment sources and sedimentation history. Heavy mineral analyses established three sediment sources: (1) the five major rivers draining the volcanic and associated sedimentary rocks of the Coast Range, (2) small streams draining the sedimentary uplands that form the shoreline...