compiled by Pete Doty – Denver Realtor


Abandonment of water right: the termination of a water right in whole or in part, resulting from the intent of the owner to permanently discontinue its use. A conditional water right may also be terminated by failure on the part of the owner to develop it with reasonable diligence until absolute, or to make filings to the water court every six years showing due diligence has been made towards perfecting the water right.

Absolute water right: a water right that has been put to a beneficial use. See definition for conditional water right.

Acre-foot: the volume of water equivalent to covering one acre of land to a depth of one foot; equal to 43,560 cubic feet or 325,851 gallons.

Adjudication: the judicial process through which the existence of a water right is confirmed by decree of the water court.

Appropriation: the right to take a certain portion of thewaters of the state to be put to beneficial use. The specific quantity and rate of flow may be confirmed by a water court decree.

Aquifer: a formation, group of formations or part of a formation containing sufficient saturated permeable (able to pass through) material that could yield a sufficient quantity of water that may be extracted and put to beneficial use.

Augmentation plan: a way for junior appropriators to obtain water supplies through terms and conditions approved by a water court that protects senior water rights from the depletions caused by the new diversions. It typically will involve storing junior water when in priority and releasing that water when a call comes on, purchasing stored water to release when a river call comes on, or purchasing senior irrigation water rights and changing the use of those rights to offset the new users’ injury to the stream. (Note: These plans can bevery complex and it is

suggested that an engineering consultant be hired to allow for proper consideration of all hydrologic and water rights factors.)

Augmentation water: water that is added, left, or replaced in a stream system to offset out-of-priority diversions.

Beneficial use: the use of a reasonable amount of water necessary to accomplish the purpose of the appropriation without waste. Some common types of beneficial use are: domestic, household use, irrigation, municipal, wildlife, recreation, and mining.

Call: a request by a water right appropriator that more junior water rights on the same drainage system curtail their diversions of water to the extent necessary, such that sufficient water is made available to satisfy the senior water right placing the call. Such calls are administered by the Division Engineer and staff for the division in which the call was placed.

Change of water right: any change in any way that a water right is used. It can be changed in type, place or time of use, point of diversion, adding points of diversion, etc. It is not considered a change in use if a farmer changes the type of crop grown or the type of irrigation method. Changes of water rights must be approved by the water court to assurethat no injury occurs to other water rights.

Conditional water right: a water right obtained through the water court where the water has not been placed to a beneficial use. It gives the holder of that right time to complete a project as long as they diligently pursue completion of the project. Every six years, the court reviews what progress has been made toward completion of the project. Once the right has been placed to beneficial use, the holder of the conditional right must then ask the court to make it an absolute water right. See definition for Absolute water right.

Consumptive use: the amount of water that is lost to the stream system, for example, through crop consumption or evaporation, when applying water to beneficial uses.

Cubic feet per second: a rate of flow of water passing a given point each second of time, amounting to one cubic foot. This is equal to 7.48 gallons per second, 448.8 gallons per minute or approximately two acre-feet per day.

Decree: an official document issued by the water court including, but not limited to, the priority date, amount, use, and location of the water right.

Depletion: the withdrawal of water from a surface or ground water stream or basin at a rate greater than the rate of replenishment. Depletion is determined for a system by subtracting system outflows from system inflows.

Designated ground water: ground water that, in its natural course, is not available to or required for the fulfillment of decreed surface rights, or ground water in areas not adjacent to a continuously flowing natural stream, wherein ground water withdrawals have constituted the principal water usage for at least 15 years preceding the date of the first hearing on the proposed designation of the basin, and which is within the geographic boundaries of a designated ground water basin.

Designated ground water basins or “designated basins”: those areas of the state established by the Ground Water Commission in accordance with Section 37-90-106, CRS. The designated basins are located in the Front Range and in eastern Colorado. There are currently eight designated basins.

Diversion: to divert and control water from its natural course by means of a structure.

Division Engineer: the State Engineer’s principal water official in each of the seven water divisions (also see glossary of terms, State Engineer and Water divisions).

Exempt uses: any recognized uses that are not subject to administration under the priority system. For further information, see Sections 37-92-602 and 37-90-105, CRS.

Exempt well: a well allowed to be used for exempt uses. For further information, see Sections 37-92-602 and 37-90-105, CRS.

Arch Ditch Diversion Structure

Ground water:any water not visible on the surface of the ground under natural conditions.

Ground Water Commission: a twelve-member body created by the Legislature, nine of which are appointed by the Governor to carry out and enforce the state statutes, rules and regulations,decisions, orders and policies of the Commission, dealing with designated ground water.

Ground water management district: any district organized under Section 37-90-118 to 37-90-135, CRS, for the purpose of consulting with the Ground Water Commission on all designated ground water matters within a particular district. There are currently 13 districts.

Irrigation year: the irrigation year for the purposes of recording annual diversions of water for irrigation in Colorado begins November 1 and ends on October 31 of each year.

Junior water right: a relative term describing a water right with a priority less than that of a “senior right” from a common source of water.

Native waters: surface and underground waters naturally occurring in a watershed.

Non-consumptive: uses that do not reduce the quantity of water available to the stream system.

Non-exempt uses:any recognized beneficial uses of water that are administered under the priority system. For further information, see Sections 37-90-137 and 37-90-107, CRS.

Non-exempt well: a well allowed to be used for non-exemptuses.

Non-native waters: waters imported or not originally hydrologically connected to a watershed or drainage basin physically or by statute; non-tributary ground water and transmountain water are non-native.

Nontributary ground water: ground water located outside the boundaries of any designated ground water basin, where the withdrawal of this ground water by a well will not, within 100 years, deplete the flow of a natural stream at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal.

Not Nontributary ground water: ground water located within those portions of the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers that are outside of any designated ground water basin in existence on January 1, 1985, the withdrawal of which will, within 100 years, deplete the flow of a natural stream at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal.

Over-appropriated: a water rights term used to describe a surface water drainage system that has more decreed water rights claims on the system than can be satisfied by the physical supply of water available.

Potability: a reference to water that does not contain pollution, contamination, or infective agents, and is considered to be safe for human consumption.

Priority:the right of a senior water rights holder to divert water before a junior water rights holder from a common source. Priority is based on both the appropriation date and adjudication date of a water right, as confirmed by the water court.

Recharge area: reservoirs and ditches that are designed to replenish groundwater depletions, due to out-of-priority diversions, by artificially introducing water into the ground water aquifer.

Resume: a monthly publication by the water court of a summary of water rights applications filed in the water court that month.

River basin: the land area and water catchment surrounding a river from its headwaters to its mouth.

River call: usually a written document filed with the Division Engineer stating that, as of a certain date and time, a water right holder is not receiving all of the water they are entitled to by decree, and are requesting that the Division Engineer shut down all upstream water rights junior to them until their senior right is satisfied.

Senior water right: a relative term describing a water right with a priority greater than that of a “junior right” from a common source of water.

State Engineer: the Governor-appointed chief state water official in charge of administering the waters of the state.

Structure: any apparatus constructed to divert water, such as a headgate, pipe, or well.

Transmountain diversions: water that is diverted from one watershed to another across the Continental Divide.

Tributary water: water that is hydrologically connected to a natural stream system either by surface or underground flows.

User supplied data: data or records of water uses provided by an owner/user that has not been verified by state officials.

Water commissioner: state water official, appointed by the State Engineer and working under the direction of the Division Engineers, who performs the day-to-day administration of surface and ground water in each water district (also see glossary terms, Division Engineer, State Engineer, Water districts, Water divisions).

Water Court: a district court that hears matters related to  water. To obtain a judicially recognized water right, change a water right or obtain an augmentation plan, requesting persons or entities file applications with one of these courts and the court will issue a decree or order.

Water districts:eighty geographical divisions of the state that were originally used for the granting of water rights. The districts are now largely used for administrative purposes.

Water divisions: the seven geographical areas of the state of Colorado corresponding to the major natural surface water drainages. The seven divisions are: Division 1-South Platte River Basin; Division 2-Arkansas River Basin; Division 3-Rio Grande River Basin; Division 4-Gunnison River Basin; Division 5-Colorado River Basin; Division 6- Yampa/White River Basins; Division 7-San Juan/Dolores River Basins.

Water right: a property right that is either conditional or absolute and conveys the right to use a particular amount of water, with a specified priority date as confirmed by the water court, or by the Ground Water Commission if within the designated ground water basins (also see glossary terms, Absolute water right and Conditional water right).

Well: any structure or device used for the purpose, or with the effect, of obtaining ground water for beneficial use from an aquifer. Additionally, any test hole or other excavation that is drilled, cored, bored, washed, fractured, driven, dug, jetted, or otherwise constructed, when the intended use of such excavation is for the location, monitoring, dewatering, observation, diversion, artificial recharge, or acquisition of ground water, or for conducting pumping equipment or aquifer tests.

Standard Water Use Rates

♦ Each ordinary household use: 0.3 acre-foot per year

♦ Use for four large domestic animals: 0.05 acre-foot per


♦ Use for each 1,000 square feet of lawn irrigation: 0.05

acre-foot per year

Water Conversions

♦ 1 cfs (cubic feet per second): 646,560 gallons per day

(gpd); 449 gallons per minute (gpm)

Per 24 hours: 1.983 acre-feet (AF)

♦ 1 acre-foot: 325,851 gallons

♦ 1 cubic foot: 7.48 gallons