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Glossary of Terms

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the amount of water needed to cover one acre of land one foot deep; about 326,000 gallons


an underground layer of rock, sediment or soil that is filled or saturated with water


a groundwater reservoir defined by the overlying land surface and underlying aquifers that contain water stored in the reservoir


something produced in addition to the principal product


the treatment of a substance, such as drinking water, with chlorine and ammonia (chloramines) in order to kill disease-causing organisms


the process of removing salt from seawater or brackish water


an interacting network of groups of organisms together with their non-living or physical environment


water changing into vapor and rising into the air


passing water through coal, sand and gravel to remove particles

Fish ladder

a device to help fish swim around a dam


a unit of measure equal to four quarts or 128 fluid ounces


water underground, such as in wells, springs and aquifers

Hydrologic cycle

the natural recycling process powered by the sun that causes water to evaporate into the atmosphere, condense and return to earth as precipitation

Imported water

water brought into an area from a distant source, such as from one part of a state to another via an aqueduct


supplying water to agriculture by artificial means, such as pumping water onto crops in an area where rainfall is insufficient

Municipal Water District

a public water provider, owned and operated by more than one city government, which supplies water to its member cities


condition that occurs in a groundwater basin when pumping exceeds the amount of replenishment over a period of years

Perennial yield

maximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft condition


carries water underground to homes and businesses


water falling toward the Earth's surface in the form of rain, drizzle, hail, sleet, or snow


increases in groundwater storage from precipitation, infiltration from streams, or human activity (artificial recharge), such as putting surface water into spreading basins


a pond or lake where water is collected and stored until it is needed


liquid water that travels over the surface of the Earth, moving downward due to the law of gravity; runoff is one way in which water that falls as precipitation returns to the ocean

Unconfined Aquifer

an aquifer that discharges and recharges with an upper surface that is the water table

Unit of water

One hundred cubic (CCF) feet is equal to 748 gallons

Water Cycle

the movement of water from the air to and below the Earth's surface and back into the air

Water Quality

the condition of water as it relates to impurities

Water Table

(1) the boundary in the ground between where the ground is saturated with water (zone of saturation) and where the ground is filled with water and air (zone of aeration); (2) the upper surface of the saturated zone that determines the water level in a well in an unconfined aquifer


a geographical portion of the Earth's surface from which water drains or runs off to a single place like a river; also called a drainage area


a hole or shaft drilled into the earth to get water or other underground substances


landscaping that doesn't require a lot of water