Wade To walk in or through water or something else that similarly impedes normal movement.
Wadi, also Wady A ravine or watercourse, dry except in the rainy season and some are permanently dry.  Also see Arroyo.
Waft (1) To cause to go gently and smoothly through the air or over water.  (2) To convey or send floating through the air or over water.
Wake The visible track of turbulence left by something moving through water.
(Final) Walker River Decree See Decree C-125 (Final Walker River Decree) ( Nevada).
(Interim) Walker River Decree See Decree 731 (Interim Walker River Decree) ( Nevada).
Walker River Irrigation District (WRID) (Nevada) The litigation of Pacific Live Stock Company v. Antelope Valley Land and Cattle Company and the issuance of Decree 731 caused a number of farmers in Smith and Mason valleys to band together in April 1919 and form the Walker River Irrigation District (WRID
Wallow A pool of water or mud where animals go to wallow; the depression, pool, or pit produced by wallowing animals.
Warm Front The interface between an advancing mass of air that is warmer than the one it is replacing, usually at the point of contact with the ground surface.
Warm Spring A spring that brings warm water to the surface.  A thermal spring.  Temperatures typically are 15?F (9.5?C) or more above the mean air temperature.
Warning Stage The Stage (or Gage Height) at which a general state of readiness must be maintained by concerned river interests in the event of further rises above Flood Stage (similar to a Watch).  In some cases, initial action must be taken by concerned interests, such as livestock and equipment removal from the lowest overflow areas.  This level may produce overbank flows sufficient to cause minor flooding of low-lying areas and local roads.
Wash (1) To carry, erode, remove, or destroy by the action of moving water.  To be carried away, removed, or drawn by the action of water.  Removal or erosion of soil by the action of moving water.  (2) A deposit of recently eroded debris.  (3) Low or marshy g
Wash Load In a stream system, the relatively fine material in near-permanent suspension which is transported entirely through the system without deposition.
Washoe Project (Nevada) Operated by the U.S. Bureau of Reclamation (USBR), the project provides flood control, hydroelectric power, and fishery and wildlife enhancement on the Truckee River.  Principal features of the project include Prosser Creek Dam and Reservoir, Stampeded Dam and Reservoir, Stampede Power Plant, Marble Bluff Dam, and the Pyramid Lake Fishway.
Washoff Materials transported from a land or soil surface by overland flow, often used to describe soil materials transported off runoff test plots.
Washout (1) Erosion of a relatively soft surface, such as a roadbed, by a sudden gush of water, as from a downpour or floods.  (2) A channel produced by such erosion.
Wasteload Allocation (WLA) A system designed to limit the total discharge of pollutant materials into a receiving body of water.  Each Point Source (PS) of pollutants is allowed to release a specific fraction of the total amount of pollutant materials that can be expected to be assimilated by the stream.  Pollution from Non-Point Sources (NPS) comprises the steam's Load Allocation.
Waste Pipe A pipe that carries off liquid waste.
Waste Treatment Lagoon An impoundment made by excavation or earth fill for biological treatment of wastewater.  Also see Constructed Wetland and Lagoon.
Waste Treatment Plant A facility containing a series of tanks, screens, filters and other processes by which pollutants are removed from water.  More commonly referred to as Wastewater Treatment Plant.
Wastewater (1) A combination of liquid and water-carried pollutants from homes, businesses, industries, or farms; a mixture of water and dissolved or suspended solids.  (2) That water for which, because of quality, quantity, or time of occurrence, disposal is more economical than use at the time and point of its occurrence.  Waste water to one user may be a desirable supply to the same or another user at a different location.  Also referred to as Domestic Wastewater.
Wastewater Infrastructure The plant or network for the collection, treatment, and disposal of sewage in a community.  The level of treatment will depend on the size of the community, the type of discharges, and the designated use of the receiving water.
Wastewater Operations and Maintenance Actions taken after the construction of a Wastewater Treatment Plant to assure that the facilities will be operated, maintained, and managed to reach prescribed effluent levels in an optimum manner.
Wastewater Reclamation The planned reuse of waste water for specific beneficial purposes.
Wastewater Treatment Any of the mechanical or chemical processes used to modify the quality of waste water in order to make it more compatible or acceptable to man and his environment.
Wastewater Treatment Plant A water effluent treatment facility containing a series of tanks, screens, filters and other mechanical, biological, and chemical processes by which pollutants are removed from water.  Less frequently referred to as Waste Treatment Plant.
Wasteway (1) Channel for conveying or discharging excess water or wastewater.  (2) (Irrigation) Structure used to divert surplus flow from the main canal into a natural or constructed drainage channel.
Waste Utilization Using an agricultural or other waste on land in an environmentally acceptable manner while maintaining or improving soil and plant resources.
Water (H2O) The liquid that descends from the clouds in rain and which forms streams, lakes, and seas, and is a major constituent of all living matter.  Pure water consists of Hydrogen (11.188 percent by weight) and Oxygen (88.812 percent by weight) in the proportion
Water (1) To pour or sprinkle on, make wet.  (2) To dilute or weaken by adding water.  (3) To irrigate land.  (4) To take on a supply of water, as a ship.  (5) To drink water, as an animal.  (6) Any of various forms of water, for example, fresh water, waste water, etc.; often waters, as naturally occurring mineral water, such as those at a spa.  (7) A body of water such as a sea, lake, river, or stream; waters, as a particular stretch of sea or ocean, especially that of a state or country, for example, U.S. waters.
Water Administration A broad term referring to the collective role of defined state agencies to implement state and federal water laws, commonly through the development and implementation of appropriate statutes and regulations.  This role can include oversight, approval, and enforcement responsibilities.
Water Alliances For Voluntary Efficiency (WAVE) A water conservation program conceived by the U.S. Environmental Protection Agency (EPA) in December 1992 and designed to help increase water efficiency in U.S. lodging facilities.  The program encourages participating hotels to install water efficient technologies for bathroom fixtures, dish washing and laundry facilities, cooling towers, and landscaping.  The program's goal is to reduce water use and associated energy consumption, help inform hotel guests and employees about the importance of water conservation, and help hotels realize a monetary savings for their efforts.  Program components consist of technical assistance, research material availability, computer software programs to survey water use and evaluate options, and public recognition of participation.
Water Allocation In a hydrologic system in which there are multiple uses or demands for water, the process of measuring a specific amount of water devoted to a given purpose or use.
Water Analysis The determination of the physical, chemical, and biological characteristics of water.  Such analysis usually involves four kinds of examination:  bacterial, chemical, microscopic, and physical.
Water Application Efficiency The ratio of the volume of water stored in the root zone of a soil during irrigation to the volume of water applied.
Water Audit A procedure that combines flow measurements and listening surveys (leak detection) in an attempt to give a reasonably accurate accounting of all water entering and leaving a system.
Water Balance (1) A measure of the amount of water entering and the amount of water leaving a system.  Also referred to as Hydrologic Budget.  Also see Hydrologic Equation.  (2) The ratio between the water assimilated into the body and that lost from the body; also, the condition of the body when this ratio approximates unity.
Water Ballet A synchronized sequence of movements performed by a group of swimmers.
Water Bank A mechanism for holding water for eventual use.  A water bank may include the use of surface water reservoirs, underground storage facilities (e.g., groundwater recharge), or a combination of these mechanisms.
Water Banking A water conservation and use optimization system whereby water is reallocated for current use or stored for later use.  Water banking may be a means of handling surplus water resources and may involve aquifer recharge or similar means of storage.  Typically, under such arrangements, an agency is created with the authority to purchase, sell, hold, and transfer water and water rights in addition to serving as a negotiator between buyers and sellers.  In its broadest sense, all water rights would be covered under such water banking arrangements to include surface water, groundwater, treated wastewater effluent, and irrigation tailwater.  Generally, participants in water banking arrangements will have their water rights protected from cancellation (non-beneficial use) for a specific period so long as their water is "deposited" in the water bank.  Also see Water Marketing.
Water-Based Recreation Those activities which require water for participation such as boating, swimming, sailing and canoeing.
Water Bloom An accumulation of algae and especially of blue-green algae at or near the surface of a body of water.  Also referred to as Algal Bloom.
Waterborne (1) Floating on or supported by water, as, for example, afloat.  (2) Transported or carried by water, for example, a disease transmitted by water contaminated by a disease-causing microorganism.  (3) Transmitted in water.
Waterborne Disease Outbreak The significant occurrence of acute infection illness associated with drinking water from a Public Water System (PWS) that is deficient in treatment, as determined by appropriate local or state agencies, or from untreated water sources.
Water, Bottled See Bottled Water.
Water Budget (1) (Hydrology) An accounting of the inflows to, the outflows from, and the storage changes of water in a hydrologic unit or system.  Also see Water Balance.  (2) (Conservation and Planning) The calculated amount of water a household should use based on the type and number of fixtures, landscape requirements, and size of family.
Water Classification The separation of water in an area into classes according to usage, such as domestic consumption, fisheries, recreation, industrial, agricultural, navigation, power production, waste disposal, etc.  Also see Water Use, Types.
Water Clock The water clock, or Clepsydra, has been reliably dated to 1600 BC in Egypt.  It functioned by water dripping through a hole in the base of a container, which lowered the water level past markings on the container sides.  These markings were spaced to indicate fixed periods of time. Many variations were based on this design.  Ctesibius of Alexandria made a clepsydra in which a figure floating on the water surface pointed to the time scale.  In another type, dripping water turned a wheel that was connected to pointers on a dial face similar to a modern clock.  Before the third century BC the clepsydra was used by the Greeks to indicate intervals of time, especially in law court; later it functioned as a clock.  Clepsydras were later used in Rome, the Arab world, and China.
Water Color One of the most immediately apparent attributes of many natural waters and one that, together with visual clarity, strongly influences human aesthetic perception and recreational use.  Color of waters is a guide to their composition, and remote sensing of
Water Column A hypothetical cylinder of water from the surface to the bottom of a stream, lake, or ocean within which the physical and/or chemical properties can be measured.
Water Commissioner A person whose job is to make sure the water of each stream under his or her control is distributed in proper quantities at the right times to those who are authorized to receive it.  Also referred to as Ditch Rider or Mayordomo.  May be elected or hired by local water users or appointed by a state authority such as the state engineer or a judge.
Water Commitment A commitment from a water purveyor to provide water service to a particular parcel of land and/or a specific development.
Water Conservation The physical control, protection, management, and use of water resources in such a way as to maintain crop, grazing, and forest lands, vegetative cover, wildlife, and wildlife habitat for maximum sustained benefits to people, agriculture, industry, commerce, and other segments of the national economy.  Water conservation measures result in a reduction in applied water due to more efficient water use such as the implementation of Best Management Practices (BMP), Urban Water Use, or Efficient Water Management Practices (EWMP)- Agricultural Water Use.  The extent to which these actions actually create a savings in water supply depends on how they affect new water use and depletion.
Water Conserving Irrigation System Irrigation systems including a combination of drip irrigation, soaker hoses, bubblers, and low-trajectory spray heads for water distribution; zoning irrigation for different water-demand plant types; electronic timers with five-day programming and rain override devices, irrigation schedules for early morning watering every five to seven days; and soil moisture sensors.
Water Consumed See Consumptive Use.
Water Contamination Impairment of water quality to a degree which reduces the usability of the water for ordinary purposes, or which creates a hazard to public health through poisoning or spread of disease.
Water Content of Snow The amount of liquid water contained in a snowpack.  Also referred to as the Snow Water Equivalent (SWE) and is measured in inches of water.
Water Control (Soil and Water Conservation) The physical control of water by such measures as conservation practices on land, channel improvements, and installation of structures for water retardation and sediment detention.  As defined, this concept does not refer to the legal control of water rights.
Water-Cooled Reactor A nuclear reactor that employs water to cool the reactor core.  A nuclear reactor is a device designed to promote the fission of an appropriate fuel (such as uranium-235) in a controlled manner.  The heat produced during the fission event must be removed from the device to prevent an excessive buildup.  Water is usually used as the heat transfer agent.  Other coolants used in nuclear reactors of other designs are liquid sodium and inert gases.  Also see Light Water Reactor (LWR).
Watercourse A depression formed by runoff moving over the surface of the earth; any natural or artificial channel through which water flows; a lake, river, creek, stream, wash, arroyo, channel or other topographic feature on or over which waters flow at least periodically.  Watercourses include specifically designated areas in which substantial flood damage may occur.
Watercourse Bed That portion of the watercourse which carries water at ordinary stages.
Watercraft (Nautical) A boat or ship; water vehicles considered as a group.
Water Crossing A commonly used route for crossing a river or stream.
Water Cushion A pool of water maintained to absorb the impact of water flowing from an overfall structure.
Water Cycle The cycle of evaporation and condensation that controls the distribution of the earth's water as it evaporates from bodies of water, condenses, precipitates, and returns to those bodies of water.  Also referred to as the Hydrologic Cycle.
Water Dating To date groundwater, scientists determine how much of an isotope (such as carbon-14) is still present.  An isotope is an element, such as carbon or chlorine, with one or more extra neutrons in its nucleus.  By knowing the precise rate of decay of a radioa
Water Dedications A controversial water rights policy that involves a trade-off in which a user can begin pumping groundwater in exchange for a guarantee to buy and retire a like amount of surface water in the future.  Critics of the policy argue that dedications are often difficult to enforce and can lead to overuse of groundwater when a user fails to fulfill on the guarantee.
Water Delivery System Reservoirs, canals, ditches, pumps, and other facilities to move water.
Water Demand The water requirements for a particular purpose, such as irrigation, power production, municipal supply, plant transpiration, or storage.
Water Demand Schedule A time distribution of the demand for prescribed quantities of water for specified purposes.  It is usually a monthly tabulation of the total quantity of water that a particular water user intends to use during a specified year.
Water Desalination The removal of salts, such as from a saline water supply, usually by Electrodialysis or Reverse Osmosis.
Water Dilution Volume (WDV) The volume of water required to dilute radioactive waste to a concentration meeting drinking water standards.  Typically expressed in cubic meters of water per metric ton of radioactive waste.
Water Discharge The amount of water and sediment flowing in a channel, expressed as volume per unit of time.  The water contains both dissolved solids (Dissolved Load) and suspended sediment (Suspended Load).
Water Disposal System The complete system for removing excess water from land with minimum erosion.  For sloping land, this may encompass a terrace system, terrace outlet channels, dams, and grassed waterways.  For level land, it may include only surface drains or both surface and subsurface drains.
Water Duty The total volume of irrigation water required to mature a particular type of crop.  In stating the duty, the crop, and usually the location of the land in question, as well as the type of soil, should be specified.  It also includes consumptive use, evaporation and seepage from on-farm ditches and canals, and the water that is eventually returned to streams by percolation and surface runoff.  Also see Alpine Decree (California and Nevada), Orr Ditch Decree (California and Nevada), Bench Lands (Nevada), and Bottom Lands (Nevada), for additional information and examples of specific water duties.
Water Duty (Nevada) The Alpine Decree and Orr Ditch Decree provide the basis for virtually all irrigation water duties relating to water diversions from the Truckee, Carson, and Walker rivers in Northern Nevada.  These decrees provide for an annual maximum irrigation duty of
Water Education For Teachers (Project WET) (Nevada) A statewide supplementary, interdisciplinary water education program with components for the education community (K-12) and the general public.  The goal of Nevada Project WET is to facilitate and promote the awareness, appreciation, knowledge, and stewar
Water Equivalent (of Snow) The depth or amount of water that would result from the complete melting of a sample of deposited snow, measured in inches of water.
Waterer (1) A person who obtains or supplies drinking water.  (2) A device used for supplying water to livestock and poultry.  Also referred to as Drinker.
Water Exports The artificial transfer (pipes, canals, aqueducts, etc.) of water to one region or subregion from another region.  Also see Interbasin Transfers, Water Importation, and Water Imports.
Waterfall A sudden, nearly vertical drop in a stream, as it flows over rock.
Waterflood The process of waterflooding an oil well; to pump water into the ground around an oil well nearing depletion in order to loosen and force out additional oil.
Water Flow The rate of flow of water measured in volume and time (e.g., cubic feet per second, or cfs).
Waterfront (1) Land abutting a body of water.  (2) The part of a town or city that abuts water, especially a district of wharves where ships dock.
Water Gap A traverse cleft in a mountain ridge through which a stream flows; the gap cut through a resistant ridge by a superimposed or Antecedent Stream.
Water Garden (1) A garden in which aquatic plants predominate.  (2) A garden built about a stream or pool as a central feature.
Water Gate A gate that provides access to a body of water; a Floodgate.
Water Gauge An instrument indicating the level of water, as in a boiler, tank, reservoir, or stream.
Water Glass An open tube or box having a glass bottom for making observations below the surface of the water.
Water Hammer (1) Very rapid pressure wave in a conduit due to a sudden change in flow; the potentially damaging slam, bang, or shudder that occurs in a pipe when a sudden change in water velocity (usually as a result of too-rapidly starting a pump or operating a valve) creates a great change in water pressure.  (2) A banging noise in steam pipes, caused by steam bubbles entering a cold pipe partially filled with water.
Water Hole A small natural depression in which water collects, especially a pool where animals come to drink.
Water Hyacinth A floating freshwater plant belonging to the genus Eichhornia.  The plant was introduced into the United States in the late nineteenth century and has become a prolific nuisance weed that clogs waterways in the southern part of the country.
Water Ice A dessert made of finely crushed ice that has been sweetened and flavored.
Water Importation The act or process whereby water is brought into an area or region which would not naturally receive such waters.  Typically, it refers to the artificial transport of water through aqueducts, canals, or pipelines from one water basin, drainage area, count
Water Imports The artificial transfer (pipes, canals, aqueducts, etc.) of water into one region or subregion from another region.  Also see Water Importation, Water Exports, and Interbasin Transfers.
Water Impoundment A body of water created or stored by impoundment structures such as dams, dikes, and levees.
Watering Place (1) A place where animals find water to drink; a watering hole.  (2) A health resort with mineral springs; a spa.
Watering Point A central source from which people without piped water can draw drinking water and transport it to their homes.
Waterish Resembling water; watery.
Water Jacket A casing containing water circulated by a pump, used around a part to be cooled, especially in water-cooled internal-combustion engines.
Water Law A law that has been instigated to control the right to the use of water.  See (Prior) Appropriation Doctrine and Riparian Doctrine.
Water Law (California) The keystone to California's water law and policy, as spelled out in the California Constitution, requires that all uses of the State's waters be both reasonable and beneficial.  It places a significant limitation on water rights by prohibiting the waste,
Water Law (Federal) Except when provided by federal law, e.g., Federal Reserved (Water) Rights, federal water rights must satisfy the administration and permitting process of the state in which the federal project is located.  An important 1978 U.S. Supreme Court case (California v. United States) held that unless state law conflicted with clear Congressional directives, the federal government must obtain water rights under state law for reclamation purposes.  Under the federal reserved rights concept, the federal government reserves sufficient water rights when it withdraws land from the public domain to establish a federal reservation such as a national park or Indian reservation.  Also see Reservation Doctrine, Reserved Rights Doctrine, and Winters Doctrine and Winters Rights (Decision).
Water Law (Nevada) Nevada's water law is based on the Prior Appropriation Doctrine.  Furthermore, unlike some other states, Nevada has a statewide system for the administration of both ground water and surface water.  Appropriative Water Rights are based on the concept of applying water to Beneficial Use and "First in Time, First in Right".  Appropriative water rights can be lost through nonuse and they may be sold or transferred apart from the land.  Due in large part to the relative scarcity of water in Nevada and numerous competing uses, Nevada has had a thriving market for water transfers for a number of years.  Water rights in Nevada are administered by the State Engineer.  Also see Application, Water Right, Riparian Doctrine, Riparian Water Rights, Littoral Water Rights, Prescribed Water Rights, and Reserved Water Rights.
Waterless (1) Lacking water; dry.  (2) Not requiring water, as a cooling system.
Water Level (1) An instrument to show the level by means of the surface of water in a trough or in a U-shaped tube.  (2) The surface of still water.  (3) The level assumed by the surface of a particular body or column of water.  (4) The water-surface elevation or stage of the free surface of a body of water above or below any datum (see Gage Height), or the surface of water standing in a well, usually indicative of the position of the water table or other potentiometric surface.  (5) (Hydrology) Synonymous with the Water Table.  (5) The Water Line of a ship.
Water-Level Gage A gage which indicates the water level in a reservoir, stilling well, or other receptacle.
Water Level Pivot Point A location along the water surface in a canal reach where the water level remains essentially constant during changes in flow.
Water Line (Nautical) (1) The line on the hull of a ship to which the surface of the water rises.  (2) Any of several lines parallel to this line, marked on the hull of a ship, and indicating the depth to which the ship sinks under various loads.  (3) A pipeline carrying water.  (4) A line marked on a structure or gage to indicate water depth.  May be more specifically referred to as a high water line or a low water line when measuring water depths.
Waterlog, also Waterlogged, Waterlogging (1) To soak or saturate with water.  (2) A soil condition in which a high or perched water table is detrimental to plant growth, resulting from over-irrigation, seepage, or inadequate drainage.  Also, the replacement of most of the soil air by water.  (3) (Nautical) To make heavy and sluggish in the water because of flooding, as in the hold of a ship.
Water Loss (1) The sum of water lost from a given land area during a specified time period by transpiration, evaporation, and interception.  (2) In irrigation, seepage and evaporation from land and ditches; excess water drained from the land surfaces and the deep percolation.  The basic concept is that water loss is equal to Evapotranspiration, that is, water that returns to the atmosphere and thus is no longer available for use.  However, the term is also applied to differences between measured inflow and outflow even where part of the difference may be Seepage.
Water Losses Water which is unavailable or lost from a particular containment system.
Water Main A principal pipe in a system of pipes for conveying water, especially one installed underground.
Waterman (1) A man who makes his living from the water (as by fishing).  (2) A boatman who plies for hire, usually on inland waters or harbors.
Water Management (1) (General) Application of practices to obtain added benefits from precipitation, water, or water  flow in any of a number of areas, such as irrigation, drainage, wildlife and recreation, water supply, watershed management, and water storage in soil for
Watermark (1) A mark showing the greatest height to which water has risen.  (2) A line indicating the heights of high and low tide.
Water Marketing A concept of water transfer and use borne out of increased demand by urban populations for water whereby a holder of water rights is allowed to sell or lease those rights in an open market to the highest bidder.  As an example, in the United States one ac
Water Mass (Oceanography) An oceanographic term that refers to a large body of water whose density characteristics are distinct from the surrounding aquatic environment because of inherent temperature or salinity differences.  Water masses are present in all oceans and are formed where water flows from one type of climatic or physiographic region into another.  The North Atlantic Current is an example of a water mass distinguished by a difference in temperature.  It is a relatively warm water body that retains its identity as far north as the Arctic Circle.  The huge freshwater volume expelled by the Amazon River into the southern Atlantic Ocean is an example of a water mass distinguished by a difference in salinity.
Watermaster Often an employee of a court hired to administer a court decree.  Also may be an employee of a water department who distributes available water supplies at the request of water rights holders and collects hydrographic data.  Also refers to a position within an irrigation project that is responsible for the internal distribution of project water.
Watermaster-Reported Headgate Deliveries The watermaster-reported, measured and/or estimated farm headgate deliveries.
Water Meter An instrument for recording the quantity of water passing through a particular outlet.
Water Mill A mill whose machinery is moved by water.
Water Molecule The smallest unit of water (chemical symbol H2O); consists of two atoms of Hydrogen (chemical symbol H) and one atom of Oxygen (chemical symbol O).
Water of Crystallization Water in chemical combination with a crystal, necessary for the maintenance of crystalline properties but capable of being removed by sufficient heat.
Water of Hydration Water chemically combined with a substance in such a way that it can be removed, as by heating, without substantially changing the chemical composition of the substance.
Water Penetration The depth to which irrigation water or rain penetrates the soil before the rate of downward movement becomes negligible.
Water Permit A state license to appropriate water for a beneficial purpose.
Water Pipe (1) A pipe that is a conduit for water.  (2) An apparatus for smoking, such as a Hookah, in which the smoke if drawn through a container of water or ice and cooled before inhaling.
Water Plan A document of issues, policies, strategies and action plans intended to effectively and economically execute a Water Planning process.  Also see Water Policy.
Water Planning Water planning is an analytical planning process developed and continually modified to address the physical, economic, and sociological dimensions of water use.  As a planning process it must assess and quantify the available supply of water resources and
Water Policy Those actions governing the management, administration, and procedures used to implement and direct a formal Water Planning process by which water rights, water uses, and water diversions are evaluated, ranked, and allocated on the basis of specific publi
Water Pollution Generally, the presence in water of enough harmful or objectionable material to damage the water's quality.  More specifically, pollution shall be construed to mean contamination of any waters such as will create or is likely to create a nuisance or to re
Water Polo A goal game similar to soccer that is played in water by teams of swimmers using a ball resembling a soccer ball.
Water Potential The capability of soil water to do work as compared with free water.
Waterpower (1) The energy produced by running or falling water that is used for driving machinery, especially for generating electricity; (2) A source of such energy, as a waterfall.  (3) A water right owned by a mill.
Water Privilege The right to use water especially as a source of mechanical power.
Waterproof (1) Impervious to or unaffected by water.  (2) Made of or coated or treated with rubber, plastic, or a sealing agent to prevent penetration by water.  Also see Water-Repellent.
Water Purification See Purification (Water) and Purification Process (Water).
Water Purveyor Anyone who sells drinking water to the public, usually the owner of a Public Water Supply System (PWSS); a public utility, mutual water company, county water district, or municipality that delivers drinking water to customers.
Water Quality (1) A term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.  (2) The chemical, physical, and biological condition of water related to beneficial use.  Also see Drinking Water Standards and Drinking Water Standards (Nevada).  (See Appendix B-9 for principal threats to water quality.)
Water Quality-Based Limitations Effluent limitations applied to dischargers when mere technology-based limitations would cause violations of Water Quality Standards.  Usually applied to dischargers into small streams.
Water Quality-Based Permit A permit with an effluent limit more stringent than one based on technology performance.  Such limits may be necessary to protect the designated use of receiving waters (e.g., drinking, recreation, industrial, irrigation, etc.).
Water Quality Criteria A specific level or range of levels of water quality necessary for the protection of a water use; levels of water quality expected to render a body of water suitable for its designated use.  The criteria are set for individual pollutants and are based on different water uses, such as a public water supply, an aquatic habitat, and industrial supply, or for recreation.
Water Quality Indicators Constituents or characteristics of water that can be measured to determine its suitability for use.
Water Quality Limited Segment A portion of a stream where the condition of the water does not meet water quality standards and/or where standards are not expected to be achieved after Effluent Limitations on all Point Sources (PS) of water pollution are applied.  Therefore, controls beyond the technology-based discharge limits will be required for the stream segment to meet the Ambient Water Quality Standards.
Water Quality Management Planning for the protection of a water's quality for various Beneficial Uses, for the provision of adequate wastewater collection, treatment, and disposal for municipalities and industries, and for activities that might create water quality problems, and regulating and enforcing programs to accomplish the planning goals and laws and regulations dealing with water pollution control.
Water Quality Standard (Defined) (Nevada) (Nevada Revised Statutes 445A.420) Means the degree of pollution of water or the physical, chemical or biological condition of water, as expressed numerically or descriptively, used for controlling the quality of water in each segment of a stream and each other body of surface water in the State of Nevada.
Water Quality Standards (1) A plan for water quality management containing four major elements:  water use; criteria to protect uses; implementation plans, and enforcement plans.  An anti-degradation statement is sometimes prepared to protect existing high quality water sources.  (2) State-adopted and U.S. Environmental Protection Agency (EPA) approved ambient standards for water bodies.  The standards prescribe the use of the water body and establish the water quality criteria that must be met to protect designated uses.
Water Ranching The purchase of agricultural lands solely for the purpose of acquiring associated water rights or underlying groundwater.
Water Reactive Describing any substance that reacts spontaneously with water to release a flammable or toxic gas, such as sodium metal.
Water Reclamation The treatment of water of impaired quality, including brackish water and sea water, to produce a water of suitable quality for the intended use.
Water Recycling The treatment of urban waste water to a level rendering it suitable for a specific, direct, beneficial use.
Water-Related Disaster A cyclic event involving water during which there is threat to or loss of human life or property (e.g., flood, hurricane, tsunami, etc.).
Water-Related Disease An epidemic event caused by Waterborne virus or bacteria.  Also see Waterborne Disease Outbreak.
Water-Related Issue An allocation, use, rights, or environmental problem involving water that is complicated by the disagreement of two or more parties over the cause, effect, and/or resolution of the problem.
Water-Related Land Land on which projected use and/or management practices may significantly affect the runoff pattern or quality of the water resources to which it relates and land that is significantly affected by existing or proposed measures for management or use of the water resources to which it relates.
Water-Related Organizations See Appendix E-5 for a listing of national organizations directly involved in water-related issues.
Water-Related Recreation Activity A recreation activity dependent upon on enhanced by water, including swimming, boating, water skiing, fishing, picnicking, camping, sightseeing, hiking, and nature walks.
Water-Repellent Resistant to penetration by water but not entirely Waterproof.  Synonymous with Water-Resistant.
Water Requirement The total quantity of water, regardless of its source, required for a specified use under a predetermined or prescribed situation.
Water Requirement (Agriculture) The total quantity of water, regardless of its source, required for production of crops at their normal growth under field conditions.  It includes applied water, subsurface irrigation, and precipitation needed by the crops.
Water Reservation A water right granted by a state entity (commonly to public entities and on behalf of the public) for existing or future beneficial uses or for the maintenance of a minimum instream flow, water level, or quality of water.
Water-Resistant Synonymous with Water-Repellent.
Water Resource(s) The supply of groundwater and surface water in a given area.
Water Resource District A legal entity established by state statute to facilitate local administration in all phases of water development, utilization, and control.
Water Resource Management The decision-making, manipulative, and non-manipulative processes by which water is protected, allocated, or developed.
Water Resource Plan A planning document or process which assesses both sources and uses of water and develops strategies for their most effective and efficient use according to public needs and criteria.  Also see Water Plan, Water Planning, and Water Policy.
Water Resource Region Natural drainage basin or hydrologic area that contains either the drainage area of a major river or the combined areas of a series of rivers.
Water Resource Subregion A subregion of a Water Resource Region that includes the 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 coastal drainage area.
Water Resources Regions (United States) A 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 the 21 designated water-resources regions, delineated by the Water Resources Council in 1970, 18 are in the conterminous United States, and one each are in Alaska, Hawaii, and Puerto Rico.  The following represents a listing of U.S. water-resources regions and the states primarily and partly included:
(1)  Region 01:New England Region (Maine, New Hampshire, Massachusetts, Connecticut, Rhode Island, and part of Vermont)
(2)  Region 02:Mid-Atlantic Region (New York, Pennsylvania, New Jersey, Maryland, Washington D.C., Virginia, and parts of Vermont and West Virginia)
(3)  Region 03:South Atlantic-Gulf Region (North Carolina, South Carolina, Georgia, Alabama, Florida, and parts of Virginia and Mississippi)
(4)  Region 04:Great Lakes Region (Michigan, and parts of Wisconsin, Indiana, Ohio, and New York)
(5)  Region 05:Ohio Region (Indiana, Ohio, West Virginia, Kentucky, and parts of Illinois, Tennessee, Virginia, Pennsylvania, and New York)
(6)  Region 06:Tennessee Region (Tennessee and parts of Alabama, Georgia, Virginia, and North Carolina)
(7)  Region 07:Upper Mississippi Region (Minnesota, Wisconsin, Iowa, Illinois, and parts of Missouri and Indiana)
(8)  Region 08:Lower Mississippi Region (parts of Arkansas, Mississippi, Louisiana, Tennessee, Kentucky, and Missouri)
(9)  Region 09:Souris-Red-Rainy Region (parts of North Dakota and Minnesota)
(10)  Region 10:Missouri Region (Montana, Wyoming, North Dakota, South Dakota, Nebraska, and parts of Colorado, Kansas, Missouri, Iowa, and Minnesota)
(11)  Region 11:Arkansas-White-Red Region (Oklahoma and parts of Colorado, New Mexico, Kansas, Texas, Missouri, Arkansas, and Louisiana)
(12)  Region 12:Texas-Gulf Region (Texas and parts of New Mexico and Louisiana)
(13)  Region 13:Rio Grand Region (New Mexico and parts of Texas and Colorado)
(14)  Region 14:Upper Colorado Region (parts of Utah, Colorado, Wyoming, Arizona, and New Mexico)
(15)  Region 15:Lower Colorado Region (Arizona and parts of California, Nevada, Utah, and New Mexico)
(16)  Region 16:Great Basin Region (Nevada and parts of Utah, California, Oregon, Idaho, and Wyoming)
(17)  Region 17:Pacific Northwest Region (Washington, Oregon, Idaho, and parts of Montana, Wyoming, Nevada, and Utah)
(18)  Region 18:California Region (California and parts of Oregon and Nevada)
(19)  Region 19:Alaska Region (Alaska)
(20)  Region 20:Hawaii Region (Hawaii)
(21)  Region 21:Caribbean Region (Puerto Rico)
Also see Hydrologic Unit Maps (USGS) and Hydrologic Units (Classification Codes) (USGS).
Water Resources Sub-Region (United States) The 21 Water Resources Regions of the United States as designated by the Water Resources Council are further subdivided into 222 sub-regions.  Each sub-region 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 coastal drainage system.  Also see Hydrologic Unit Maps (USGS) and Hydrologic Units (USGS).
Water Resources Sub-Area An approximation of a Water Resources Sub-Region using county boundaries.  Also see Water Resources Region (United States).
Water Right (1) The legal right to use a specific quantity of water, on a specific time schedule, at a specific place, and for a specific purpose.  (2) A legally-protected right, granted by law, to take possession of water occurring in a water supply and to put it to Beneficial Use.  (3) A legal right to divert state waters for a beneficial purpose.
Water-Righted Acreage The land base for which there are water rights.
Water Rights (1) The legal rights to the use of water.  (2) A grant, permit, decree, appropriation, or claim to the use of water for beneficial purposes, and subject to other rights of earlier date or use, called Priority or Prior Appropriation.  They consist of Riparian Water Rights,  Appropriative Water Rights, Prescribed Water Rights, and Reserved Water Rights.  Also see Water Law, Water Law (California), Water Law (Federal), and Water Law (Nevada).
Water Rights, Correlative Doctrine When a source of water does not provide enough for all users, the water is reapportioned proportionately on the basis of prior water rights held by each user.
Water Sample A representative part of a portion used to determine quality of a larger body of water.
Water Service Agency An agency organized, founded, or established to produce and distribute water directly or indirectly to customers.  The two major types are privately owned companies which consist of commercial companies and mutual water groups; and public companies which include water districts and municipally-owned water departments.
Water Service Reliability The degree to which a water service system can successfully manage water shortages.
Watershed (1) An area that, because of topographic slope, contributes water to a specified surface water drainage system, such as a stream or river.  An area confined by topographic divides that drains a given stream or river.  (2) (Catchment) The natural or disturbed unit of land on which all of the water that falls (or emanates from springs or melts from snowpacks), collects by gravity, and fails to evaporate, runs off via a common outlet.  (3) All lands enclosed by a continuous hydrologic drainage divide and lying upslope from a specified point on a stream; a region or area bounded peripherally by a water parting and draining ultimately to a particular water course or body of water.  Also referred to as Water Basin or Drainage Basin.  (4) A ridge of relatively high land dividing two areas that are drained by different river systems.  Also referred to as Water Parting.
Watershed Area (Drainage Area) The watershed area at a point in the stream refers to the area of the earth from which the water concentrates toward that point, through the drainage system.
Watershed Lag The time from the center of mass of effective rainfall to peak of hydrograph.
Watershed Management (1) The planned manipulation of one or more factors of the natural or disturbed drainage so as to effect a desired change in or maintain a desired condition of the water resource.  (2) The analysis, protection, development, operation or maintenance of the land, vegetation and water resources of a drainage basin for the conservation of all its resources for the benefit of its residents.  Watershed management for water production is concerned with the quality and timing of the water which is produced.  Also referred to as Water Management and Basin Management.
Watershed Planning The formulation of a plan, based on the concept of a Watershed, a Water Basin, a Hydrologic Region, or a Hydrologic Study Area (HSA), with the intent to assess climatological conditions, inventory existing ground and surface water resources, determine current water uses, project future socioeconomic and environmental demands for those resources, and explore feasible water-balancing options, so as to maximize the benefits to the inhabitants of a study area while simultaneously preserving and protecting the region's wildlife, habitat, and environmental conditions.
Watershed Project A comprehensive program of structural and nonstructural measures to preserve or restore a water shed to good hydrologic condition.  These measures may include detention reservoirs, dikes, channels, contour trenches, terraces, furrows, gully plugs, revegetation, and possibly other practices to reduce flood peaks and sediment production.
Watershed Protection The treatment of watershed lands in accordance with such predetermined objectives as the control of erosion, stream flow, silting floods, and water, forage, or timber yield.  Also see Watershed Planning.
Watershed Protection Approach (WPA) A type of pollution management program supported by the U.S. Environmental Protection Agency (EPA) as being the most effective mechanism for achieving clean water and healthy, sustainable ecosystems throughout the United States.  The WPA is a "placed-based" strategy that integrates water quality management activities within hydrologically defined drainage basins or watersheds as opposed to using conventional, politically-defined boundaries.  The WPA allows stakeholders to tailor corrective actions to local concerns within the coordinated framework of a state, Tribal, and national water program.  In addition, an emphasis on public participation provides the opportunity to incorporate environmental justice issues into watershed management.  Six basic objectives form the general foundations of EPA's watershed protection process:
(1)  identifying critical watersheds with EPA and state participation;
(2)  clearly defining the problems, general causes, and specific sources of risks and impairments to the watershed;
(3)  developing potential pollution prevention and control strategies;
(4)  implementing point and nonpoint source controls;
(5)  developing scientifically valid and practical indicators for gauging and reducing the risks in the watershed; and
(6)  developing ecological criteria that states may use in formulating future watershed protection standards.
Water-Sick Land rendered unproductive because of excessive irrigation.
Waterside (1) Land bordering a body of water; a bank or shore.  (2) The margin of a body of water; a Waterfront.
Water Softener An apparatus designed to remove divalent metal ions (the most important of these being calcium, magnesium, and iron) from water, often replacing the divalent or trivalent ions with the monovalent sodium ion.  See Ion Exchange.
Water Softening Any process, but most usually involving ion exchange, for removing from water, in whole or in part, those Cations which produce hardness (primarily calcium and magnesium).  Also see Hard Water and Hardness.
Water Solubility The maximum possible concentration of a chemical compound dissolved in water.  If a substance is Water Soluble it can very readily disperse through the environment.
Water Soluble Of a material that dissolves in water.
Waterspout (1) A tornado or lesser whirlwind occurring over water and resulting in a funnel-shaped whirling column of air and spray.  (2) A hole or pipe from which water is discharged.
Water Spreading (1) (General) Diverting runoff from natural channels or gullies by means of a system of dams, dikes, or ditches, and spreading it over relatively flat areas.  The purpose is to increase the growth of natural vegetation or to infiltrate and recharge the groundwater for subsequent withdrawal by pumps for irrigation.  Also see Artificial Recharge.  (2) (Reclamation Projects) A controversial practice of using surface water from U.S. Bureau of Reclamation (USBR) irrigation projects to grow crops outside district boundaries.  As of 1995, it was estimated that across the 17 Western states water spreading occurred on at least 1.8 million irrigated acres.
Water Spreading Methods Refers to surface irrigation by border or furrow.
Waterstop A strip of metal, rubber, or other material used to prevent leakage through joints between adjacent sections of concrete.
Water Storage Pond An impound for liquid wastes designed to accomplish some degree of biochemical treatment.  Also see Waste Treatment Lagoon.
Water Supplier One who owns or operates a Public Water System (PWS).
Water Supply (1) Any quantity of available water; a Water System.  (2) The water available for a community or region.  (3) The source and delivery system of such water.
Water Supply System Includes the works and auxiliaries for collection, treatment, storage, and distribution of the water from the sources of supply to the free-flowing outlet of the ultimate consumer.  Also see Public Water System (PWS).
Water Surface Elevation (1) Generally, the elevation of a water surface above or below an established reference level, such as (mean) seal level.  (2) The height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, or other datum, of a body of water or, for flood determination, for the specification of floods of various magnitudes and frequencies in the floodplains or coastal or riverine areas.  Also see Mean Sea Level (MSL).
Water System (1) A river and all its tributaries.  (2) A Water Supply.
Water Table (1) The surface of a groundwater body at which the water is at atmospheric pressure; the upper surface of the ground water reservoir.  (2) The upper surface of the Saturated Zone that determines the water level in a well in an Unconfined Aquifer.  (3) The level of groundwater; the upper surface of the Zone of Saturation for underground water.  It is an irregular surface with a slope or shape determined by the quantity of ground water and the permeability of the earth material.  In general, it is highest beneath hills and mountains and lowest beneath valleys.  Also referred to as Ground Water Table.
Water-Table Aquifer An Unconfined Aquifer within which is found the water table.
Water Table, Perched The surface of a local zone of saturation held above the main body of groundwater by an impermeable layer or stratum, usually clay, and separated from the main body of groundwater by an unsaturated zone.
Watertight So tightly made that water cannot enter or escape.
Water Tower A standpipe or elevated tank used as a reservoir or for maintaining equal pressure in a water system.
Water Transfer(s) (1) Artificial conveyance of water from one area to another across a political or hydrological boundary.  This is referred to as an import or export of water from one basin (inter-basin) or county (inter-county) to another.  (2) Marketing arrangements that can include the permanent sale of a water right by the water right holder; a lease of the right to use water from the water right holder; the sale or lease of a contractual right to water supply.  Also see Water Importation.
Water Treatment Processes undertaken to purifier water acceptable to some specific use, e.g., drinking.  Most water treatment processes include some form, or combination of forms, of sedimentation, filtration, and chlorination.
Water Treatment, Combined Technique A relatively new water disinfection technique greatly reducing the need for chlorination while effectively destroying up to 99.9 percent of coliphage (intestinal bacteria) in raw water.  The method combines two purification techniques that have been previously used separately for water purification-potassium permanganate and copper/silver ions-but in combination the processes kill bacteria up to 10 times faster than metal ions alone and up to 5 times faster than potassium permanganate alone.
Water Treatment Lagoon An impound for liquid wastes designed to accomplish some degree of biochemical treatment.  Also referred to as Waste Treatment Lagoon and Water Storage Pond.
Water Treatment Plants Facilities that treat water to remove contaminants so that it can be safely used.
Water Use The amount of water needed or used for a variety of purposes including drinking, irrigation, processing of goods, power generation, and other uses.  The amount of water used may not equal the amount of water withdrawn due to water transfers or the recirculation or recycling of the same water.  For example, a power plant may use the same water a multiple of times but withdraw a significantly different amount.  Also see Water Use, Types, below.
Water Use Efficiency (1) A measure of the crop production per unit of water used, irrespective of water source, expressed in units of weight per unit of water depth per unit area.  (2) Marketable crop production per unit of water consumed in evapotranspiration.  The concept of utilization applies to both Dryland Farming and irrigated agriculture.
Water Use Practices Direct, indirect, consumptive, and nonconsumptive uses of water.  These include domestic practices (e.g., washing, bathing, cooking, drinking), navigation, wildlife habitat management, irrigation practices, recreation activities, industrial uses, and hydroelectric power generation.
Water Use, Types The use of water may be classified by specific types according to distinctive uses, such as the following:
(1)  Commercial Water Use
(2)  Domestic Water Use
(3)  Hydroelectric Power Water Use
(4)  Irrigation Water Use
(5)  Livestock Water Use
(6)  Mining Water Use