1995 Water-Use Guidelines: Appendix C - Glossary

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(A) (B) (C) (D) (E) (F) (G) (H) (I) (K) (L) (M) (N) (O) (P) (R) (S) (T) (W)


APPENDIX C: Glossary

(A)

Afterbay: A lake or water impoundment located downstream from the powerplant that receives the water after it has passed through the hydroelectric turbines.

Agriculture water use: Composed of livestock, animal specialty, and irrigation water use.

Animal Specialities water use: Water use associated with the production of fish in captivity except fish hatcheries, fur-bearing animals in captivity, horses, rabbits, and pets. See also aquaculture, fish hatcheries, and livestock water use.

Aquaculture: Farming of organisms that live in water, such as fish, shellfish, and algae within a confined space and under controlled feeding, sanitation, and harvesting procedures. Establishments primarily engaged in hatching fish and in operating fishing preserves are classified as fish hatcheries. See also animal specialities and fish hatcheries.

Aquifer: A geologic formation, group, of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs.

(B)

Blowdown: The continuous or intermittent discharge, or purging, of a small amount of circulating water, normally expressed as a percentage of the water being circulated. Its purpose is to prevent an increase in the concentration of solids in the water due to evaporation.

(C)

Capacity: Is a volume when referring to a cooling tower. It is the average amount of water circulating in the cooling system at any given time, expressed in gallons per minute. This is not the production capacity of the power generation plant.

Commercial water use: Water used for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions. The water may be obtained from a public supply or may be self supplied. See also public supply and self-supplied water.

Consumptive use: That part of water withdrawn that is evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. Also referred to as water consumed.

Conveyance loss: Water that is lost in transit from a pipe, canal, conduit, or ditch by leakage or evaporation. Generally, the water is not available for use; however, leakage from an irrigation ditch, for example, may percolate to a ground-water source and be available for further use.

Cooling water: Water used for cooling purposes, such as of condensers and nuclear reactors.

(D)

Delivery/release: The amount of water delivered to the point of use and the amount released after use; the difference between these amounts is usually the same as the consumptive use. See also consumptive use.

Desalination: Refers to the removal of salts from water. Desalination is primarily used to produce public-supply water that meets drinking water standards. The primary types of desalination are: distillation, electrodialysis, and reverse osmosis. Additionally, many public suppliers also dilute or blend saltwater with fresher water to produce potable water.

Dewatering: (1) The draining, pumping, or removal of water that is affecting construction or mining site, or to lower the water table for agriculture. (2) The removal of water from a substance (sewage or waste screenings, for example).

Domestic water use: Water for household purposes, such as drinking, food preparation, bathing, washing clothes and dishes, flushing toilets, and watering lawns and gardens. Also called residential water use. The water may be obtained from a public supply or may be self- supplied. See also public supply and self-supplied water.

Drift: The fine water droplets blown out of a cooling tower with the exhaust air, expressed as a percentage of water circulated. Drift loss can be held to 0.2 percent of the circulating water (Weisman, 1985).

(E)

Evaporation: Process by which water is changed from a liquid into a vapor. See also evapotranspiration and transpiration.

Evapotranspiration: A collective term that includes water discharged to the atmosphere as a result of evaporation from the soil and surface-water bodies and as a result of plant transpiration. See also evaporation and transpiration.

(F)

Fish farm water use: Water used for the production of finfish and shellfish under controlled feeding, sanitation, and harvesting procedures for sale or market consumption. Water use by fish farms is classified under the animal specialities subcategory of livestock water use. See also animal specialities, aquaculture, and fish hatcheries.

Fish hatchery water use: Water used for raising fish for later release, used in associated with the operation of fish hatcheries or fishing preserves. The production of fish under controlled feeding, sanitation, and harvesting procedures are classified under animal specialities. The water used by fish hatcheries is classified as a commercial water use. See also animal specialities, aquaculture, fish farms, and livestock water use.

Forebay: A lake or water impoundment (reservoir) located at the end of a diversion canal or conduit and before the entrance to the powerplant.

Freshwater: Water that contains less than 1,000 mg/L of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses.

(G)

Geothermal power water use: The use of water in the generation of electricity at plants where the energy is extracted from water that is heated by the internal heat of the earth.

Gigawatt-hour (GWh): A unit of energy equivalent to one billion watt-hours.

Ground water: Generally all subsurface water as distinct from surface water; specifically, that part of the subsurface water in the saturated zone (a zone in which all voids are filled with water).

(H)

Hydroelectric power water use: The use of water in the generation of electricity at plants where the turbine generators are driven by falling water.

(I)

In-channel use: See instream use.

Industrial water use: Water used for industrial purposes such as fabrication, processing, washing, and cooling, and includes such industries as steel, chemical and allied products, paper and allied products, smelting, and petroleum refining. The water may be obtained from a pubic supply or may be self supplied. See also public supply and self-supplied water.

Instream use: Water that is used from a surface-water source for such purposes as hydroelectric power generation, navigation, water-quality improvement, fish propagation, and recreation. Sometimes called nonwithdrawal use or in-channel use.

Irrigation district: A cooperative, self-governing public corporation set up as a subdivision of the State government, with definite geographic boundaries, organized and having taxing power to obtain and distribute water for irrigation of lands within the district; created under the authority of a State legislature with the consent of a designated fraction of the landowners or citizens.

Irrigation system [irrigation]: Practices and equipment used in providing and distributing water to the land/crop being irrigated. Main systems and some associated terms are listed (technological advances are ongoing to reduce cost and improve efficiencies:

Irrigation water use: Artificial application of water on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands such as parks and golf courses.

(K)

Kilowatt-hour (kWh): A unit of energy equivalent to one thousand watt-hours.

(L)

Livestock water use: Water for livestock watering, feed lots, dairy operations, fish farming, and other on-farm needs. Livestock as used here includes cattle, sheep, goats, hogs, and poultry. Also included are animal specialties, and fish farms. See also rural water use, animal specialties, and fish hatcheries.

(M)

Makeup: The water pumped into the system to replace the circulating water lost by evaporation, drift, blowdown and leakage; expressed as a percentage of the water circulated.

Mining water use: Water use for the extraction of minerals occurring naturally including solids, such as coal and ores; liquids, such as crude petroleum; and gases, such as natural gas. Also includes uses associated with quarrying, well operations (dewatering), milling (crushing, screening, washing, floatation, and so forth), and other preparations customarily done at the mine site or as part of mining activity. Does not include water used in processing, such as smelting, refining petroleum, or slurry pipeline operations; these uses are included in industrial water use.

(N)

Non-account water: The difference between public-supply withdrawals and deliveries. Also known as public-supply residual or public use and loss.

(O)

Offstream use: Water withdrawn or diverted from a surface-water source for public-water supply, industry, irrigation, livestock, thermoelectric power generation, and other uses. Sometimes called off-channel use or withdrawal.

(P)

Per capita water use: The average amount of water used per person during a standard time period, generally per day.

Precipitation: The liquid equivalent (depth) of rainfall, snow, sleet, or hail. The data that is used is more correctly referred to as "Observed Precipitation" and in all cases is somewhat less than actual due to the imperfectness of measuring devices.

Preirrigation: Application of water to cropland before planting to assure adequate crop germination and early plant growth.

Public supply: Water withdrawn by public and private water suppliers and delivered to users. Public suppliers provide water for a variety of uses, such as domestic, commercial, thermoelectric power, industrial, and public water use. See also commercial water use, domestic water use, thermoelectric power water use, industrial water use, and public water use.

Public-supply deliveries: Water provided to users through a public-supply distribution system.

Pumped storage: Storage in an afterbay that is pumped back to the forebay above the powerplant at a time when customer demand for energy is low, such as at night. Pumped storage is a method of keeping water in reserve for use during peak period power demands. In some cases, the forebay may be located offstream.

Public water use: Water supplied from a public-water supply and used for such purposes as firefighting, street washing, and municipal parks and swimming pools. See also public supply.

(R)

Reclaimed wastewater: Wastewater treatment plant effluent that has been diverted for beneficial use before it reaches a natural waterway or aquifer.

Recycled water: Water that is used more than one time before it passes back into the natural hydrologic system.

Residential water use: See domestic water use.

Return flow: The water that reaches a ground-water or surface-water source after release from the point of use and thus becomes available for further use.

Reuse: Use of water that has undergone wastewater treatment and is delivered to a user as reclaimed wastewater. See also recycled water.

Rural water use: A term used in previous water-use circulars to describe water used in suburban or farm areas for domestic and livestock needs. The water generally is self supplied, and includes domestic use, drinking water for livestock, and other uses, such as dairy sanitation, evaporation from stock watering ponds, and cleaning and waste disposal. See also domestic water use, livestock water use, and self-supplied water.

(S)

Saline water: Water that contains more than 1,000 milligrams per liter dissolved solids.

Self-supplied water: Water withdrawn from a surface-water or a ground-water source by a user and not obtained from a public supply.

Standard industrial classification (SIC) codes: Four-digit codes established by the Office of Management and Budget and used in the classification of establishments by type of activity in which they are engaged.

Surface-water: An open body of water, such as a stream or lake.

(T)

Thermoelectric power water use: Water used in the process of the generation of thermoelectric power. The water may be obtained from a public supply or may be obtained from a public supply or may be self supplied. See also public supply and self-supplied water.

Transpiration: Process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface. See also evaporation and evapotranspiration.

(W)

Wastewater: Water that carries wastes from homes, businesses, and industries.

Wastewater treatment: The processing of wastewater for the removal or reduction of contained solids or other undesirable constituents.

Wastewater-treatment return flow: Water returned to the hydrologic system by wastewater-treatment facilities.

Water use: (1) In a restrictive sense, the term refers to water that is actually used for a specific purpose, such as for domestic use, irrigation, or industrial processing. (2) More broadly, water use pertains to human's interaction with and influence on the hydrologic cycle, and includes elements such as water withdrawal, distribution, consumptive use, wastewater collection, and return flow.

Water-resources accounting unit: Many of the 222 designated water resources subregions are divided into accounting units. These 352 hydrologic accounting units nest within or are equivalent to the planning subregions. The accounting units are used by the U.S. Geological Survey for designing and managing the National Water Data Network. See water-resources subregion.

Water-resources cataloging unit: Many of the 352 water-resources accounting units are divided into cataloging units. A cataloging unit is a geographic area representing part or all of a surface drainage basin, a combination of drainage basins, or a distinct hydrologic feature. The approximately 2,150 cataloging units in the Nation are used for cataloging and indexing water-data acquisition activities. See water-resources accounting unit.

Water-resources region: Designated natural drainage basin or hydrologic area that contains either the drainage area of a major river or the combined drainage areas of two or more rivers; of 21 regions, 18 are in the conterminous United States, and one each are in Alaska, Hawaii, and the Caribbean.

Water-resources subregion: The 21 designated water resources regions of the United States are subdivided into 222 subregions. Each subregion includes that area drained by a river system, a reach of a river and its tributaries in that reach, a closed basin(s), or a group of streams forming a costal drainage system. See water-resources region.

Water transfer: Artificial conveyance of water from one area to another.

Water treatment: The processes that withdrawn water may undergo prior to use, including chlorinations, fluoridation, and filtration.

Water use: (1) In a restrictive sense, the term refers to water that is actually used for a specific purpose, such as for domestic use, irrigation, or industrial processing. In this report, the quantity of water use for a specific category is the combination of self-supplied withdrawals and public-supply deliveries. (2) More broadly, water use pertains to human's interaction with and influence on the hydrologic cycle, and includes elements such as water withdrawal, delivery, consumptive use, wastewater release, reclaimed wastewater, return flow, and instream use. See also offstream and instream use.

Watt-hour (Wh): An electrical energy unit of measure equal to one watt of power supplied to, to taken from, an electrical circuit steadily for one hour.

Withdrawal: The removal of surface water or ground water from the natural hydrologic system for use, including public-water supply, industry, commercial, domestic, irrigation, livestock, thermoelectric power generation, water uses.


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Last modified: 22 May 1996