Publications

No abstract available.

No abstract available.

The lower Colorado River is an important water resource for metropolitan populations, agriculture, and industry in California, Arizona, and Nevada. The Bureau of Reclamation (BOR) manages the river, releasing water stored in Lakes Mead, Mohave, and Havasu, and in other smaller reservoirs as needed so that it can be used by diverters. To help guide river management, streamflow and reservoir content

Ground water is one of the Nation's most important natural resources. It provides drinking water to communities, supports industry and agriculture, and sustains streams and wetlands. A long record of contributions exists in understanding ground-water movement in sand and gravel aquifers; historically, these aquifers were easily accessible and the first to be investigated. With increased demand for

Recharge to unconfined aquifers in the seven-county Twin Cities metropolitan area of Minnesota was estimated by five methods. Mean recharge estimated as a percentage (27 percent) of precipitation ranged from 7.7 to 8.3 in./yr across the study area. The median recharge estimated from automated analyses of streamflow-recession displacements for seven basins ranged from 1.2 to 12.2 in./yr. Median rec

Streambed sediments from 30 sites in the St. Croix River Basin were analyzed for selected chemical elements. Possible occurrences of low-level contamination include: (1) elevated concentrations of arsenic, lead, silver, and to a lesser extent cadmium, copper, and mercury in the Namekagon River downstream of Hayward, Wisconsin; (2) elevated lead concentrations in the St. Croix River downstream of t

No abstract available.

About 30 percent of the 238 water bodies on the 2000 State of Texas 303(d) list of impaired or threatened waters are included for not meeting optimum conditions for aquatic life (Texas Natural Resource Conservation Commission, 2000). Most of the water bodies on the list were assessed using water-column measures such as concentrations of dissolved oxygen (DO) and total metals as surrogates for aqua

Trends over the 20th Century were examined in streamflow, river ice, and snowpack for coastal river basins in Maine. Trends over time were tested in the timing and magnitude of seasonal river flows, the occurrence and duration of river ice, and changes in snowpack depth, equivalent water content, and density. Significant trends toward earlier spring peak flow and earlier center-of-volume runoff da

This report describes a three-dimensional, finite difference, ground-water-flow model of the Santa Fe Group aquifer system within the Middle Rio Grande Basin between Cochiti and San Acacia, New Mexico. The aquifer system is composed of the Santa Fe Group of middle Tertiary to Quaternary age and post-Santa Fe Group valley and basin-fill deposits of Quaternary age. Population increases in the bas

Ground water is increasingly relied upon to satisfy the needs of a growing population in the upper Deschutes Basin, Oregon. Hydrogeologic studies are being undertaken to aid in management of the ground-water resource. An understanding of the geologic factors influencing ground-water flow is basic to those investigations. The geology of the area has a direct effect on the occurrence and movement of

No abstract available.