Publications

This report presents ground-water data collected and compiled as part of a study of the ground-water resources of the Willamette River Basin, Oregon. The report includes tabulated information and a location map for 1,234 field-located water wells and 6 springs, hydrographs showing water-level fluctuations during various time periods for 265 of the wells, borehole geophysical data for 16 wells, and

As part of an ongoing cooperative study between the Unified Sewerage Agency of Washington County, Oregon, and the U.S. Geological Survey, phosphorus and Escherichia coli (E. coli) concentrations were measured in the Fanno and Bronson Creek subbasins of the Tualatin River Basin during September 1996. Data were collected at 19 main-stem and 22 tributary sites in the Fanno Creek subbasin, and at 14 m

This report presents a framework for regional water-quality monitoring in the middle and upper Deschutes River Basin, Oregon, that would be coordinated among organizations doing related monitoring. The emphasis is on maximizing the value of existing programs and resources by minimizing overlapping sampling efforts, filling key data gaps, increasing communication about results, and facilitating coo

A ground-water flow model was used in conjunction with particle tracking to estimate zones of transport for six municipal well sites in Clark County, Washington. A zone of transport for a well is a three-dimensional volume within a ground-water system that contains all of the ground water that will discharge from that well within a specified time period. All of the zones of transport for a well co

During 1987-91, chemical data were collected for pesticides and other organic compounds in surface water, streambed sediment, suspended sediment, agricultural soil, and aquatic biota to determine the occurrence, distribution, transport, and fate of organic compounds in the Yakima River basin in Washington. The report describes the chemical and physical properties of the compounds most frequently d

The report describes the distribution of trace elements in sediment, water, and aquatic biota in the Yakima River basin, Washington. Trace elements were determined from streambed sediment, suspended sediment, filtered and unfiltered water samples, aquatic insects, clams, fish livers, and fish fillets between 1987 and 1991. The distribution of trace elements in these media was related to local geol

No abstract available.

Sources and transport for phosphorous and nitrogen to the Tualatin River, Oregon, were characterized for summer (May through October) low-flow conditions during 1991, 1992, and 1993. Mass balances for water and chemical constituents, which were generated for the main-stem river, provide important context for nutrient-reduction efforts in the basin.

The discharge, water temperature, and water quality of the Tualatin River in northwestern Oregon was simulated with CE-QUAL-W2, a two-dimensional, laterally averaged model developed by the U.S. Army Corps of Engineers. The model was calibrated for May through October periods of 1991, 1992, and 1993. Nine hypothetical scenarios were tested with the model to provide insight for river managers and re

The Willamette Basin, Oregon, is one of more than 50 large river basins and aquifer systems (referred to as study units) across the United States where the status and trends of water quality and the factors controlling water quality are being studied by the National Water-Quality Assessment Program of the U.S. Geological Survey. The 12,000-square-mile Willamette Basin Study Unit consists of the Wi

In response to increasing demands on ground-water resources in the Willamette Basin, Oregon (fig. 1), the Oregon Water Resources Department (OWRD) and the U.S. Geological Survey (USGS) began a cooperative study of the basin’s ground-water resources in 1996. This study was designed to increase the current understanding of the ground-water resource, and to better characterize the distribution of nat

The Williamson River Basin, located in south-central Oregon, has a drainage area of approximately 3,000 square miles. The Sprague River, which flows into the Williamson River Basin, has a drainage area of 1,580 square miles. Together, the Williamson and Sprague Rivers supply about one-half of the inflow to Upper Klamath Lake. Various statistical techniques, which included trend tests, double-mass