aquifer
Porous, water-saturated layers of sand, gravel, or bedrock that can yield an economically significant amount of water.
Consumptive water use
using water and not returning it to its original source-mostly because of losses such as evaporation, seepage into the ground, transport to another area, or contamination.
desalination
Purification of salt water or brackish (slightly salty) water by removal of dissolved salts.
drainage basin
See watershed. Land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river).
floodplain
Flat valley floor next to a stream channel. For legal purposes, the term often applies to any low area that has the potential for flooding, including certain coastal areas.
groundwater
Water that sinks into the soil and is stored in slowly flowing and slowly renewed underground reservoirs called aquifers; underground water in the zone of saturation, below the water table.
natural recharge
Natural replenishment of an aquifer by precipitation, which percolates downward through soil and rock.
nonconsumptive use
using water in a way that does not remove, or only temporarily removes, water from an aquifer or body of surface water.
Ogallala aquifer
a nonrenewable aquifer that stretches across the U.S. Great Plains from North Dakota to Texas.
reliable runoff
Surface runoff of water that generally can be counted on as a stable source of water from year to year.
surface runoff
Water flowing off the land into bodies of surface water.
surface water
Precipitation that does not infiltrate the ground or return to the atmosphere by evaporation or water table Upper surface of the zone of saturation, in which all available pores in the soil and rock in the earth's crust are filled with water.
water table
Upper surface of the zone of saturation, in which all available pores in the soil and rock in the earth's crust are filled with water.
watershed
Land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river).
zone of aeration
Zone in soil that is not saturated with water and that lies above the water table.
zone of saturation
Area where all available pores in soil and rock in the earth's crust are filled by water.