Glossary of Water Terminology Fact Sheet No. 4.717 Crop Series|Irrigation by R. Waskom and M. Neibauer* Water is basic to our lives and all of us Artesian well: A well in which water Quick Facts are affected by how it is used and managed. under natural pressure rises to the surface In Colorado, the complexity of our water without being pumped. • Water in Colorado is laws and our water management structure Augmentation plan: A court-approved administered under is often bewildering. It seems that water plan that allows a junior water user to divert the doctrine of prior managers in Colorado have their own special water out of priority so long as adequate appropriation or “first in language. This fact sheet offers non-technical replacement is made to affected stream time, first in right doctrine”. definitions of many of the commonly system preventing injury to the water rights used water terms to help citizens better of senior users. • The state constitution understand the principles that govern the use declares that “the right to of water in Colorado. divert the unappropriated B waters of any natural stream A Base flow: The amount of water to beneficial uses shall never in a stream that results from ground be denied.” Absolute water right: A water right, with water discharge. a specified priority date, that has been placed Basin: The area of land that drains to a • The concept of beneficial to a beneficial use. particular river. use has changed with Acre foot: The volume of water required Basin rank: The relative seniority of changing public values, but to cover one acre of land to a depth of one a water right as determined by its date of includes a notion of wise foot (43,560 cubic feet or 325,851 gallons). adjudication and the date of appropriation. use, without waste. Adjudication: The judicial process Beneficial use: The application of water through which the existence of a water right necessary to accomplish the purpose of the • Water rights in Colorado are is confirmed by court decree. appropriation, without waste. Some common adjudicated or recognized Adverse use: Using decreed water owned types of beneficial use are agriculture, through the court system. by another appropriator. municipal, wildlife, recreation, and mining. Alluvial groundwater: Ground water Best Management Practices that is hydrologically connected to a surface (BMPs): Practices that are technically stream that is present in permeable geologic and economically feasible and for which material, usually small rock and gravel. significant water conservation or water Appropriation Doctrine: The system quality benefits can be achieved. of water law primarily used in the western United States under which: 1. The right to water is acquired by diverting water and C applying to a beneficial use; and 2. A right California Doctrine: A legal doctrine to water use is superior to a right developed retaining aspects of both riparian rights and later in time. the principles of prior appropriation. Appropriator: The person or persons Call: The request by an appropriator for who put water to beneficial use. water which the person is entitled to under Aquifer: Underground deposits of sand, his decree; such a call will force those users gravel, or rock saturated with water. The with junior decrees to cease or diminish their two major types of aquifers are confined diversions and pass the requested amount and unconfined. of water to the downstream senior making © Colorado State University the call. Extension. 5/02. Revised 5/12. Change of water right: Any change in a www.ext.colostate.edu way a water right is used. Can be changed in type, place, time of use, point of diversion, * R. Waskom, director of the Colorado Water Institute; M. adding points of diversion, etc. Changes of Neibauer, former Extension masters student. 5/2012 water rights must be approved by the water the geographic boundaries of a designated diverted out of priority at one point by court to assure that no injury occurs to ground water basin. replacing it with a like amount of water at other water rights. Designated ground water basins: another point. Colorado Doctrine: The doctrine Those areas of the state established by the Exempt uses: Any recognized uses that regulating water usage by priority of Ground Water Commission located in the are not subject to administration under the appropriation as opposed to riparian rights. Front Range and Eastern Colorado. priority system. See appropriation doctrine. Developed water: Water that is Exempt well: A well allowed to be Compact: An agreement between states produced or brought into a water system pumped out of priority. apportioning the water of a river basin to through the efforts of people, where it each of the signatory states. would not have entered the water system on Compact call: The requirement that its own accord. F an upstream state cease or curtail water Diligence: Action taken towards the Federal reserved rights: An implied diversions from the river system that is the perfection of a conditional water right. water right that occurs when the federal subject of the compact so that downstream Direct flow right: Water diverted government withdraws its land from the states’ compact entitlements may be met. from a river or stream for use without public domain and reserves it for a federal Conditional water right: The legal interruption between diversion and use purpose, the government, by implication preservation of a priority date that provides except for incidental purposes, such as reserves appurtenant water then a water user time to develop his or her settling or filtration. unappropriated to the extent needed to water right, but reserves a more senior Diversion: Removal of water from its accomplish the purpose of the reservation. date. A conditional right becomes an natural course or location by canal, pipe, or Firm annual yield: The yearly amount absolute right when water is actually put to other conduit. of water that can be dependably supplied beneficial use. Division engineer: The state engineer’s from the raw water sources of a given water Conservancy district: A special taxing principal water official in each of the seven supply system. district, created by a vote of the district’s water divisions. Floodplain: A low area of land adjacent electors, that has authority to plan, develop, Drainage basin: All the land that serves to a stream or other water course which is and operate water supply and/or potable as a drainage for a specific stream or river. subject to flooding and holds the overflow water projects. Drought: An extended period with of water during a flood. Often delineated on Conservation district: A geographical below average precipitation. the basis of the 100 year storm event. area designated by the State Legislature for Fresh water: Low salt content water water management purposes with a board (less than 0.5 parts per thousand dissolved appointed by county commissioners. E salts). Consumptive use: 1. Any use of water Effluent: Water discharged after use. Futile call: A situation in which a junior that permanently removes water from the Effluent exchange: The practice of priority will be permitted to continue to natural stream system. 2. Water that has exchanging wastewater effluent for other divert in spite of demands by a senior been evaporated, transpired, incorporated water sources without causing injury to appropriator in the same watershed, into products, plant tissue, or animal tissue other water rights as a replacement source because to curtail the junior from diversion and is not available for immediate reuse. of water for diversion of water farther would not be effective to produce water for Cubic feet per second (cfs): A rate of upstream that would otherwise have been beneficial use for the senior. water flow at a given point, amounting to out of priority. Endangered Species Act: Federal a volume of one cubic foot for each second G of time. Equal to 7.48 gallons per second, law that governs how animal and plant 448.8 gallons per minute, or 1.984 acre feet species whose populations are dangerously Ground water: Ground water, as per day. in decline or close to extinction will be opposed to surface water, is water that does protected and recovered. not run off, and is not taken up by plants, Erosion: Natural process in which soil but soaks down into an aquifer; a supply of D and land surface is worn down or washed fresh water under the earth’s surface which Decree: An official document issued by away by the action of water, wind, ice, forms a natural reservoir. the court defining the priority, amount, use, or landslides. Ground Water Commission: A twelve and location of the water right. Eutrophication: The process of surface member body created by the legislature, Decreed water right: A court water nutrient enrichment causing a water nine of which are appointed by the decision placed on a water right that is body to fill with aquatic plants and algae. Governor to carry out and enforce the then administered by Colorado’s Water Evaporation: The process of changing state statutes, rules, regulations, decisions, Resources Department. a liquid to a gas (vapor); for example, when orders, and policies of the Commission Depletion: The loss of water from water turns into steam or water vapor. dealing with designated ground water. surface water reservoirs or groundwater Evapotranspiration (ET): Process by Ground water management district: aquifers at a rate greater than that which water is evaporated from soil surface Any district organized for the purpose of recharge. and water is transpired by plants growing of consulting with the ground water Designated ground water: Ground on that surface. commission on all designated ground water water which, in its natural course, is not Exchange: A process by which matters within a particular district. available to or required for the fulfillment of water, under certain conditions, may be decreed surface rights, and which is within H Municipal water system: A network of O Head gate: A control structure or gate pipes, pumps, and storage and treatment Over-appropriated: A water rights term upstream of a lock or canal; A floodgate facilities designed to deliver potable water used to describe a surface water drainage that controls the flow of water, as in a ditch. to homes, schools, businesses, and other system that has more decreed water rights Hydraulics: Study of practical users in a city or town and to remove and claims on the system than can be satisfied applications of liquid in motion. treat waste materials. by the physical supply of water available. Hydrologic cycle: The cycle of water movement from the atmosphere to earth N and back again through evaporation, P National Environmental Policy Act transpiration, condensation, precipitation, Percolation: The downward movement (NEPA): Federal law enacted to ensure the percolation, runoff, and storage. See of water in soil; the infiltration of water into integration of natural and social sciences water cycle. the ground. and environmental design in planning and Hydrology: The science dealing with Point of diversion: A specifically decision-making for federal projects or the waters of Earth – their distribution named place where water is removed from projects on federal lands. and movement on the surface and a body of water. National Pollution Discharge underground; and the cycle involving Point source pollution: Pollution Elimination System (NPDES) Permit: A evaporation and precipitation. coming from a single identifiable source permit required under Section 401 of the such as discharge pipes from industry or Clean Water Act regulating discharge of sewer plants or other means of conveyance I pollutants into the nation’s waterways. including ditches, channels, sewers, Infiltration: Water moving into the Native waters: Surface and underground and containers. ground from a surface supply such as waters naturally occurring in a watershed. Potable: Water that is considered precipitation or irrigation. Non-consumptive use: Water drawn safe for domestic human consumption; In-stream flow: Non-consumptive for use that is not consumed. For example, drinkable water. water requirements that do not reduce the water withdrawn for purposes such as Priority: 1. The right of an earlier water supply, such as water required for hydropower generation. It also includes appropriator to divert from a natural maintaining flowing streams for fish or for uses such as boating or fishing where the stream in preference to a later appropriator. recreational boating. water is still available for other uses at the 2. Seniority date of a water right or Irrigation district: A legal entity same site. conditional water right to determine their created by statute in order to develop large Non-exempt uses: Any recognized relative seniority to other water rights irrigation projects. beneficial uses of water that are and conditional water rights deriving Irrigation year: The irrigation year for administered under the priority system. water from a common source. Priority is a the purposes of recording annual diversions Non-exempt well: A well allowed function of both the appropriation date and of water for irrigation in Colorado begins to be used for non-exempt uses such the relevant adjudication date of the right. November 1 and ends on October 31 of as irrigation. Priority date: The date of establishment each year. Non-native waters: Water imported or of a water right. The rights established by not originally hydrologically connected to application have the application date as the a watershed or drainage basin physically or date of priority. J by statute; non-tributary groundwater and Junior rights: Water rights that transmountain water are non-native. are more recent than older or more Non-tributary ground water: R senior rights. Underground water in an aquifer which is Raw water: Untreated water. situated so that it neither draws from nor Recharge: Ground water supplies are contributes to a natural surface stream in replenished, or recharged, when rain or L any measurable degree. snowmelt enters the saturation zone. Leaching: The process where material Nonpoint source pollution: Pollution Recharge area: Reservoirs and ditches in the soil (such as nutrients, pesticides, coming from a wide, non-specific source that are designed to replenish ground water etc.) are washed into lower layers of soil by such as runoff from cities, farms, or depletions, due to out of priority diversions, the downward movement of water. forest land. by artificially introducing water into the Not non-tributary ground water: ground water aquifer. Statutorily defined as ground water located M Reclaimed water: Effluent usable for within those portions of the Dawson, irrigation or ready for release into lakes Minimum streamflow requirement: Denver, Arapahoe, and Laramie-Fox hills and rivers. Water right decreed to the Colorado aquifers that are outside of any designated Reservoir: A natural or artificial place Water Conservation Board requiring that ground water basin in existence on to store water; water storage created by a set amount of water be maintained in a January 1, 1985. building a dam; a pond, lake, or basin used water course for the purpose of reasonably for the storage, regulation, and control maintaining the environment. of water. Resume: A monthly publication by Source water protection spring: Plan Tributary ground water: Water the water court of a summary of water for maintaining quality of a drinking water present below the earth’s surface that is rights applications filed in the water court supply. The point at which the water table hydrologically connected to a natural that month. meets earth’s surface, causing water to flow surface stream. Return flow: The amount of water that from the ground. reaches a surface or ground water source State engineer: The chief executive after it has been released from the point office in the executive department of the U of use and thus becomes available for state government who administers the Unappropriated water: Water which further reuse. adjudication decrees of court, defining has not been appropriated, and in which no Reuse: To use again; to intercept for water rights. other person has or claims superior rights subsequent beneficial use, either directly or Storage water rights: Colorado law and interests. by exchange. Water that would otherwise provides for “appropriation by storage” User supplied data: Data or records return to the steam system. of water that will captured in reservoirs of water uses provided by an owner/ Reverse osmosis: A water treatment and subsequently be put to beneficial use user which has not been verified by method used to remove dissolved inorganic in priority. Storage water applications are state officials. chemicals and suspended particulate matter submitted to water court for adjudication from a water supply. Water, under pressure, and decree similar to other water rights. W is forced through a semi-permeable Structure: Any apparatus constructed membrane that removes molecules larger to divert water, such as a head gate, pipe, Wastewater: Water that has been than the pores of the membrane. or well. used and contains unwanted materials Riparian Doctrine: A legal concept in Sublimation: The transition of water from homes, businesses, and industries; which owners of lands along the banks of from the solid phase (snow) directly to the a mixture of water and dissolved or a stream or body of water have the right to vapor phase without melting. suspended substances. reasonable use of the water and a correlative Surface water: Water on the surface Wastewater treatment: Any of the right protecting against unreasonable use of the ground (lakes, rivers, ponds, mechanical or chemical processes used to by others that substantially diminishes floodwater, oceans, etc.); precipitation modify the quality of wastewater in order the quantity or quality of water. The right which does not soak into the ground or to make it more compatible or acceptable to is appurtenant to the land and does not return to the atmosphere by evaporation or humans and the environment. depend on prior use. Riparian rights are not transpiration. Water and sanitation districts: A recognized in Colorado. Surge irrigation: A method of special taxing district formed by the Riparian water right: The legal right irrigation using computerized valves to residents of the district for the combined held by an owner of land contiguous to or turn the water supply on and off to move purpose of providing potable water and bordering on a natural stream or lake, to water more uniformly down the field. sanitary wastewater services. take water from the source for use on the Water commissioner: State water contiguous land. officials, appointed by the state engineer River basin: The land area surrounding T and working under the direction of the one river from its headwaters to its Transbasin diversion: The conveyance division engineers, who perform the mouth; the area drained by a river and of water from its natural drainage basin into day-to-day administration of surface and its tributaries. another basin for beneficial use. ground water in each water district. River call: Usually a written document Transmountain diversion: Water conservation: The wise use of filed with the division engineer stating that The conveyance of water from one water with methods ranging from more as of a certain date and time, a water right drainage basin to another across the efficient practices in farm, home and holder is not receiving all of the water they Continental Divide. industry to capturing water for use through are entitled to by decree, and are requesting Transpiration: The process by water storage or conservation projects. that the Division Engineer shut down or which water absorbed by plants (usually Water court: A special division of curtail all upstream water rights junior to through the roots) is evaporated into a District Court with a District Judge them until their senior right is satisfied. the atmosphere from the plant surface designated as and called the Water Judge (principally from the leaves). to deal with certain specific water matters Treated water: Water that has been principally having to do with adjudication S filtered and/or disinfected; sometimes used and change of point of diversion. There are Safe Drinking Water Act (SDWA): interchangeably with “potable” water. seven water courts in Colorado. Federal legislation that regulates the Tributary: A tributary is generally Water cycle: Transition and treatment of water for human consumption. regarded as a surface water drainage movement of water involving evaporation, Requires testing for and elimination of system which is interconnected with a transpiration, condensation, precipitation, contaminants for the protection of human river system. Under Colorado law, all percolation, runoff, and storage. health. surface and groundwater, the withdrawal Water development: The process of Senior rights: Water rights that have of which would affect the rate or direction building diversion, storage, pumping, and/ been established first and are older than of flow of a surface stream within 100 or conveyance facilities. junior rights. years, is considered to be tributary to a natural stream. Water districts: Eighty geographical Well: Any structure or device used for divisions of the state that originally were the purpose or with the effect of obtaining used for the granting of water rights. ground water for beneficial use from an The districts are now largely used for aquifer. A shaft or hole into the Earth to tap administrative purposes. an underground supply of water. Water diversion: Changing the natural Wellhead Protection Program: An flow of water to another location by using amendment to the federal Safe Drinking dams, canals, or pipelines. Water Act in 1986. Initiated to minimize Water divisions: The seven geographical the potential for contamination of public areas of the State of Colorado corresponding ground water supplies. to the major natural surface water drainages. Wetland: An area of land that is Water quality standard: Recommended regularly wet or flooded, such as a marsh or or enforceable maximum contaminant swamp. Other common names for wetlands levels of chemicals or substances in water. are sloughs, ponds, and marshes. These levels are established for water used by municipalities, industries, agriculture, and recreation. Standards may also X be narrative. Xeriscape: The use of plant Water right: A right to use, in materials and practices that minimizes accordance with its priority, a certain landscaping water use; usually native amount of water. plants; environmentally friendly form of Water storage: The locations in which landscaping. The term “xeriscape” was water is stored. They can be above ground copyrighted by Denver Water in 1981. in lakes, rivers, and other waterways or below ground as ground water. Note: These definitions are offered to Water table: The upper level of ground assist the public in understanding some of water; the level below which soil and rock Colorado’s most often used water terms. If are saturated with water. you desire a legal definition, please contact Watershed: The region draining into a water attorney. a river, river system or body of water; the total land area, regardless of size, above a given point on a waterway that contributes runoff water to the flow at that point; all the land that serves as a drainage for a specific stream or river.

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