abandonment*

Loss of whole or part of a water right by intent to permanently discontinue use.

absolute water right

A water right, with a specified priority date, that has been placed to a beneficial use.

acre foot

The volume of water required to cover one acre of land to a depth of one foot (43,560 cubic feet or 325,851 gallons).

adjudication

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

Appropriation Doctrine

The system of water law primarily used in the western United States under which: 1. The right to water is acquired by diverting water and applying to a beneficial use; and 2. A right to water use is superior to a right developed later in time.      

appropriator

The person or persons who put water to beneficial use.

augmentation plan

A court-approved plan that allows a junior water user to divert water out of priority so long as adequate replacement is made to affected stream system preventing injury to the water rights of senior users.

available supply*

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The maximum amount of reliable water supply, including surface water, groundwater, and purchases under secure contracts.

beneficial use

The application of water necessary to accomplish the purpose of the appropriation, without waste. Some common types of beneficial use are agriculture, municipal, wildlife, recreation, and mining.

block*

A quantity of water for which a price per unit of water (or billing rate) may be established

budget (water use)*

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An accounting of total water use or projected water use for a given location or activity

California Doctrine

A legal doctrine retaining aspects of both riparian rights and the principles of prior appropriation.

carry-over storage*

The amount of water carried over from season to season through both wet and dry cycles in storage facilities.

change of water right

Any change in a way a water right is used. Can be changed in type, place, time of use, point of diversion, adding points of diversion, etc. Changes of water rights must be approved by the water court to assure that no injury occurs to other water rights.

Colorado Doctrine

The doctrine regulating water usage by priority of appropriation as opposed to riparian rights. See appropriation doctrine.

compact

An agreement between states apportioning the water of a river basin to each of the signatory states.

compact call

The requirement that an upstream state cease or curtail water diversions from the river system that is the subject of the compact so that downstream states’ compact entitlements may be met.

conditional water right

The legal preservation of a priority date that provides a water user time to develop his or her water right, but reserves a more senior date. A conditional right becomes an absolute right when water is actually put to beneficial use.

conjunctive use*

Combined use of surface and ground water in a coordinated manner.

cooperative agreements

Methods for sharing water resources in cases of scarcity, which include legal agreements, such as dry year leasing, transfers, augmentation plans, water conservation easements, water banking, and substitute water supply plans.

conservation (water)*

Those practices, techniques, programs, and technologies that increase the productivity of a water supply and use in order to satisfy water needs without compromising desired water services. Includes water use efficiency, wise water use, system efficiency, and supply substitution.

conservancy district

A special taxing district, created by a vote of the district’s electors, that has authority to plan, develop, and operate water supply and/or potable water projects.

conservation district

A geographical area designated by the State Legislature for water management purposes with a board appointed by county commissioners.

conservation pricing*

Water rate structures that help achieve beneficial reductions in water usage.

consumptive use

1. Any use of water that permanently removes water from the natural stream system. 2. Water that has been evaporated, transpired, incorporated into products, plant tissue, or animal tissue and is not available for immediate reuse.

cubic feet per second (cfs)

A rate of water flow at a given point, amounting to a volume of one cubic foot for each second of time. Equal to 7.48 gallons per second, 448.8 gallons per minute, or 1.984 acre feet per day.

curtailment*

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Actions that forego or reduce desired water uses; e.g., prohibition on lawn watering or car washing during a drought.

deficit irrigation**

An information management technique used to schedule deficits in water availability during periods when crops are relatively insensitive to soil water deficits, resulting in beneficial consumptive use.

drought (agricultural)*

A climatic excursion involving a shortage of precipitation sufficient to adversely affect crop production or range production.

drought (hydrological)*

A period of below average water content in streams, reservoirs, ground water aquifers, lakes and soils.

drought (meteorological)*

A period of abnormally dry weather sufficiently prolonged for the lack of water to cause serious hydrologic imbalance in the affected area.

dry year leasing*

Negotiation of temporary water transfers for specific hydrologic and climatic conditions.

duty of water**

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The water required to satisfy consumptive use needs and also to account for these losses for any given irrigation system.

evaporation

The process of changing a liquid to a gas (vapor); for example, when water turns into steam or water vapor.

evapotranspiration (ET)

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Process by which water is evaporated from soil surface and water is transpired by plants growing on that surface.

fallow

Arable land not under rotation that is set aside for a period of time ranging from one to five years before it is cultivated again; or land usually under permanent crops, meadows or pastures, that is not being used for such purposes for a period of at least one year.

firm annual yield

The yearly amount of water that can be dependably supplied from the raw water sources of a given water supply system.

Futile Call Doctrine*

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Under this doctrine, junior water users are curtailed only if such curtailment makes water available at the time and place of injury to a senior. This allows juniors to continue diverting in times of scarcity, even if a senior is not receiving its whole entitlement, where curtailment of the junior would not allow any additional water to reach the senior.

gray water*

Water captured after initial use and reused for non-potable purposes such as irrigation, usually with minimal treatment.

ground water

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Ground water, as opposed to surface water, is water that does not run off, and is not taken up by plants, but soaks down into an aquifer; a supply of fresh water under the earth’s surface which forms a natural reservoir.

in-stream flow

Non-consumptive water requirements that do not reduce the water supply, such as water required for maintaining flowing streams for fish or for recreational boating.

Interruptible Supply Agreements*

Water rights transferred on a temporary basis for specific needs

irrigation efficiency**

The ratio of water quantity consumptively used or stored for later use to the quantity delivered

irrigation scheduling*

A method for optimizing outdoor water use by matching the watering schedule to plant needs; can refer to manual or automated scheduling

irrigation year

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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

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A water customer, usually industrial or wholesale, whose usage is substantial relative to other users; large-volume users may present unique peaking or other demand characteristics.

leak detection*

A systematic search for water loss in a delivery system or at an end users location. Considered a means of water conservation, repairing leaks found through leak detection controls the loss of water that water agencies have paid to obtain, treat, and pressurize and the loss of water consumers have purchased.

limited irrigation***

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When water supplies are restricted in some way to the point that full evapotranspiration demands cannot be met which may be caused by droughts, seasonal water fluctuations, restricted pumping allocation, and limited capacity of irrigation wells.

measure (conservation)*

A technology or practice that directly reduces water use

meter*

An instrument for measuring and recording water volume

metering*

The measurement of water use with a meter to generate data on actual customer use, which is often used for billing purposes. It has been found that billing customers based on actual water use contributes directly to water conservation and aids in detecting leaks throughout a water system.

microirrigation

A method for delivering slow, frequent applications of water to soil using low pressure, low volume distribution system and special flow-control outlets. Microirrigation methods include micro-sprinklers or sprayers, drip irrigation and subsurface drip irrigation.

Model Plan*

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A template for water conservation plan structure and content; includes the “scope of work” recommended headings and content) and worksheets for each planning step.

native waters

Surface and underground waters naturally occurring in a watershed.

non-consumptive use

Water drawn for use that is not consumed. For example, water withdrawn for purposes such as hydropower generation. It also includes uses such as boating or fishing where the water is still available for other uses at the same site.

non-native waters

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

phreatophyte*

A plant that obtains water from the water table or the unsaturated zone just above it. Often found along water supply canals, phreatophytes can consume significant quantities of water through evapotranspiration, reducing the availability of water to a water system and its users.

Prior Appropriation Doctrine*

Commonly described as "first in time first in right." Under this doctrine, rights to water are granted upon the appropriation of a certain quantity of water to a beneficial use, within a reasonable amount of time. The date of appropriation determines the priority of the water right, with the earliest appropriation establishing the most senior, or superior, right.

priority

1. The right of an earlier appropriator to divert from a natural stream in preference to a later appropriator. 2. Seniority date of a water right or conditional water right to determine their relative seniority to other water rights and conditional water rights deriving water from a common source. Priority is a function of both the appropriation date and the relevant adjudication date of the right.

priority date

The date of establishment of a water right. The rights established by application have the application date as the date of priority.

priority system*

The relative seniority of a water right which determine the right to divert the water in relation to other rights in periods of limited supply.

program (conservation)*

An action or policy that encourages, requires, or otherwise leads to implementation of water-saving measures.

purchase lease-back arrangement

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An alternative agricultural water rights transfer technique where irrigated lands will eventually become dry but secures land status through an easement for dryland farming or its preservation as open space (SWSI 2007).

raw water

Untreated water.

reclaimed water

Effluent usable for irrigation or ready for release into lakes and rivers.

return flow

The amount of water that reaches a surface or ground water source after it has been released from the point of use and thus becomes available for further reuse.

reuse (water)

To use again; to intercept for subsequent beneficial use, either directly or by exchange. Water that would otherwise return to the steam system.

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 or curtail all upstream water rights junior to them until their senior right is satisfied.

rotational fallow agreement

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An agricultural conservation technique that enables the producer to set aside different parcels of land each year as part of the normal arable rotation. The producer receives annual compensation payments in return for the lost yield and only until the land in fallow returns to production.

saved water**

Refers to a fraction of a diverter’s water supply that becomes available as a result of conservation practices or water system improvements.

salvaged water**

Water reclaimed from a nonbeneficial loss of water diverted under a valid water right. Such losses could include evaporation, transpiration, or seepage that does not return to the stream or aquifer system upon which other rights depend.

senior water rights

Water rights that have been established first and are older than junior rights.

Substitute Water Supply Planning*

Planning for temporary transfers of water during periods of shortage or while looking for permanent sources.

surge irrigation

A method of irrigation using computerized valves to turn the water supply on and off to move water more uniformly down the field.

system efficiency*

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Water conserving improvements to a water supply and distribution system, such as operational changes that stretch supplies or distribution system leak repairs that reduce water losses.

transfers (water)*

Exchange of water among willing buyers and sellers.

transpiration

The process by which water absorbed by plants (usually through the roots) is evaporated into the atmosphere from the plant surface (principally from the leaves).

treated water

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Water that has been filtered and/or disinfected; sometimes used interchangeably with “potable” water.

unappropriated water

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Water which has not been appropriated, and in which no other person has or claims superior rights and interests.

Water Availability Task Force (WATF)*

This governmental task force is comprised of Colorado’s water supply specialists from state, local and federal governments, as well as experts in climatology and weather forecasting. The WATF monitors snow pack, precipitation, reservoir storage, and stream flow and provides a forum for synthesizing and interpreting water availability information. When the WATF determines that drought conditions are reaching significant levels, it notifies the Governor and recommends activation of the Drought Mitigation and Response Plan.

water bank****

An alternative agricultural water rights transfer mechanism that supports the lease, exchange or loan of legally stored water

water banking*

Pooling of surplus water rights for rental to other water users.

Water Conservation Act*

The “Water Conservation Act of 2004,” which amended Section 37-60-126 of the Colorado Revised Statutes concerning water conservation planning by covered entities and the role of the state with regards to plan review and approval

water call

The request by an appropriator for water which the person is entitled to under his decree; such a call will force those users with junior decrees to cease or diminish their diversions and pass the requested amount of water to the downstream senior making the call.

water commissioner

State water officials, appointed by the state engineer and working under the direction of the division engineers, who perform the day-to-day administration of surface and ground water in each water district.

water court

A special division of a District Court with a District Judge designated as and called the Water Judge to deal with certain specific water matters principally having to do with adjudication and change of point of diversion. There are seven water courts in Colorado.

water diversion

Changing the natural flow of water to another location by using dams, canals, or pipelines.

water right

A right to use, in accordance with its priority, a certain amount of water.

water use efficiency*

Technologies and practices that provide the same or better level of end-use service.

water waste****

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The diversion of more water than is needed for beneficial use and cannot be included within the measure of a water right.