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Aquifers of the United States Withdrawal rates from the Ogallala Aquifer.. This is a list of some aquifers in the United States.. Map of major US aquifers by rock type. An aquifer is a geologic formation, a group of formations, or a part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to groundwater wells and springs.
Groundwater availability is worrisome for the Borrego Valley because water levels have decreased more than 100 feet in some areas of the basin. [8] The Borrego Valley Hydrologic Model was created to recreate historic conditions so that past movement and use of both surface and groundwater could be analyzed, in hopes of addressing what future ...
Summary of hydrologic and physical properties of rock and soil materials as analyzed by the Hydrologic Laboratory of the U.S. Geological Survey 1948-1960. U.S. Geological Survey Water Supply Paper 1839-D. 42 p. De Wiest, R. J. (1966). On the storage coefficient and the equations of groundwater flow. Journal of Geophysical Research, 71(4), 1117 ...
The Ogallala Aquifer (oh-gə-LAH-lə) is a shallow water table aquifer surrounded by sand, silt, clay, and gravel located beneath the Great Plains in the United States. As one of the world's largest aquifers, it underlies an area of approximately 174,000 sq mi (450,000 km 2) in portions of eight states (South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico, and Texas). [1]
As of 2010 there are six levels in the hierarchy, represented by hydrologic unit codes from 2 to 12 digits long, called regions, subregions, basins, subbasins, watersheds, and subwatersheds. The table below describes the system's hydrologic unit levels and their characteristics, along with example names and codes.
In 2008 the USGS abandoned traditional methods of surveying, revising, and updating topographic maps based on aerial photography and field checks. [34] Today's U.S. Topo quadrangle (1:24,000) maps are mass-produced, using automated and semiautomated processes, with cartographic content supplied from the National GIS Database. [34]
The Lost Pines Groundwater Conservation District's Well Watch Program lets owners get their wells recorded to help protect our aquifers.
As shown in the USGS figure, aquifers are frequently associated with compressible layers of silt or clay. Groundwater surface drawdown. As the groundwater is pumped out, the effective stress changes, precipitating consolidation, which is often non-reversible. Thus, the total volume of the silts and clays is reduced, resulting in the lowering of ...