Glossary of Terms

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

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

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

by-productssomething produced in addition to the principal product

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

county water authoritya public water district serving a county-wide area

desalinationthe process of removing salt from seawater or brackish water

droughta prolonged period of below-average precipitation

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

endangered speciesa species of animal or plant threatened with extinction

evaporationwater changing into vapor and rising into the air

filtrationpassing water through coal, sand and gravel to remove particles

fish laddera device to help fish swim around a dam

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

groundwater water underground, such as in wells, springs and aquifers

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

hydrologythe scientific study of the behavior of water in the atmosphere, on the Earth‚ surface and underground

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

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

local runoffwater running off a local area, such as rainfall draining into a nearby creek

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

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

perennial yieldmaximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft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

pipelinecarries water underground to homes and businesses

precipitationwater falling toward the Earth‚ surface in the form of rain, drizzle, hail, sleet, or snow

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

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

runoffliquid 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 ‚ ì equals to 748 gallons

water cycle the movement of water from the air to and below the Earth‚ 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

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

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

xeriscapelandscaping that doesn‚ t require a lot of water