Geology topics
K. D. Evenson
Publications and source records attributed to K. D. Evenson.
Water resources of Soledad, Poway, and Moosa basins, San Diego County, California
Reclaimed water is being considered as as supplemental water supply in the Soledad, Poway, and Moosa basins, San Diego County. This report describes the geology, soils, hydrology, and cultural factors in each of the basins as they relate to use of reclaimed water. Imported water is currently the major water-supply source in the basins. Groundwater supplies are used to a limited extent for both agricultural and domestic needs. Surface water flows are intermittent and, therefore, have not been developed for use in the basins. All three of the basins have the potential for use of reclaimed water, but only the Moosa basin is currently implementing a plan for such use. Concentrations of dissolved solids, chloride, and sulfate in both ground and surface water commonly exceed local basin objectives. As of 1985, plans for use of reclaimed water are oriented toward improving the quality of the groundwater.
Water-resources monitoring in the Cottonwood Creek area, Shasta and Tehama counties, California, 1982-83
The Cottonwood Creek study area in the Redding basin, California , contains a network of wells established to provide baseline information on ground-water levels and quality prior to the completion of two proposed dams, one on Cottonwood Creek and one on South Fork Cottonwood Creek. Analysis of monthly ground-water levels from September 1982 through September 1983 shows lowest water levels in autumn and highest in spring. The ground-water surface slopes east and has a mound at Anderson-Cottonwood Irrigation District Canal near the town of Cottonwood. Future studies here could provide additional information needed for subsequent modeling studies. Data are insufficient upstream from the damsites, specifically in areas of future impoundment where the monitoring network could be expanded. Comparison of ground-water quality samples collected from periods of lowest and highest water levels showed little chemical variation. Ground water is good to excellent with respect to recommended drinking-water standards. Ground-water types north of Cottonwood Creek are sodium magnesium or magnesium sodium bicarbonate and south of Cottonwood Creek are calcium magnesium or magnesium calcium bicarbonate. Surface-water samples from Cottonwood and South Fork Cottonwood Creeks indicate water chemically similar to ground water south of Cottonwood Creek. (USGS)
Chemical quality of ground water in Yolo and Solano counties, California
Ground-water-quality conditions were investigated in Yolo and Solano Counties during the summers of 1980 and 1981 by sampling 188 representative wells. Chemical analyses of the water samples show that the ground water is suitable for domestic and most agricultural purposes. Water samples from wells near the Sacramento River generally contained lower concentrations of dissolved solids and higher concentrations of trace elements than the rest of the study area. Ninety percent of the water sampled had a dissolved-solids concentration of less than 850 milligrams per liter. Chemical water types varied, with 72 percent of the wells sampled containing either sodium bicarbonate, magnesium bicarbonate, sodium-magnesium bicarbonate , or magnesium-sodium bicarbonate type water. A large part of the study area contains ground water with boron concentrations that exceed tolerance levels for many crops. Other toxic trace elements were present in negligible amounts. (USGS)