037-1 Wyo. Code R. § 1-4
a. A Wyoming water right is a right to use the water of the state when it is applied under the law to beneficial use, as defined by permit or adjudication and its appropriation has been made in conformance with the applicable rules and regulations. W.S. 41-3-101 states: "beneficial use shall be the basis, the measure and limit of the right to use water at all times." The right attaches to the land or place of use for which appropriated and is limited to the purpose for which appropriated. Because water is so important to the economy of this state, its use is always limited to a concept of public interest. The only uses for which water rights may be established are those which receive "public recognition" under the laws of the state.
b. A small number of water rights in Wyoming were confirmed by court decrees prior to creation of the State Board of Control and the office of the State Engineer. Generally, all other water rights acquired prior to statehood were adjudicated by the State Board of Control on the basis of "Claims to Water Filed under Territorial Law" and are known as "territorial appropriations." The first state legislature enacted a comprehensive water code, which established a filing procedure for securing water rights by permit from the State Engineer with final adjudication by the State Board of Control. The majority of Wyoming water rights have been obtained through this permit and adjudication system.
c. Permits to appropriate water are issued for the direct diversion of the natural flow of a stream, the storage of water in a reservoir, the secondary attachment of stored reservoir water to specific lands or service area, for instream flow use, and for the withdrawal or other use of water from an underground source. A direct flow diversion is measured in cubic feet per second (c.f.s.), and in the case of irrigation, is statutorily adjudicated at a rate not to exceed one c.f.s. for each 70 acres of land irrigated (except when surplus and excess flows are available - see Sections 11 and 12 ). A storage right is measured in acre-feet (a.f.) and may be filled only in order of priority. An instream flow right is measured in c.f.s. A ground water right is measured in gallons per minute (g.p.m.) pumping rate and acre-feet (a.f.) per calendar year. All water rights are limited to the beneficial uses being made. The State Engineer may deny or modify an application for permit if he or she determines that the granting of an application would be injurious in some respect.
d. After an applicant obtains a permit from the State Engineer, and then proceeds to establish the water right by applying the water to beneficial use in accordance with the terms of the permit, a proof of appropriation may be submitted to the State Board of Control. The Board will then initiate adjudication procedures in accordance with Wyoming statutes and these regulations. Amendments or corrections of unadjudicated permits are generally accomplished by petition to the State Engineer. If a water right has been adjudicated, it can only be changed or modified by the State Board of Control. A permit to appropriate water authorizes the holder to make use of the water as limited in the permit. However, a water right as such is established only when the water is applied to beneficial use. A water right is publicly recognized and specifically defined when it is adjudicated by the State Board of Control, and a certificate of appropriation is issued. Stock reservoirs, stock or domestic wells, test wells, and other temporary uses are not typically adjudicated.
e. Certain rights to use waters of the state were awarded in the Big Horn River General Adjudication. Such rights have been recognized and adjudicated by various decrees therein. In addition to the types of rights described in subsections a through d above, some water rights were awarded based on the Winters reserved water right doctrine or were established by judicial decree. Such rights are recognized by the Board as they appear in various court decrees entered in that adjudication and the same have been incorporated into the official water records of the state.
037-1 Wyo. Code R. § 1-4