Wyoming State Water Law and Prior Appropriation Doctrine

Article 8 of the Wyoming Constitution and Title 41 of the Wyoming Statutes establish a unified prior appropriation system administered by the State Engineer's Office and the Board of Control. Surface and groundwater diversions require state permits, and beneficial use determines priority. Municipal water suppliers hold state-issued rights and may impose customer watering schedules during drought, but the underlying allocation, permitting, and curtailment authority is statewide. Local outdoor watering restrictions must operate within the state's adjudicated water rights system and cannot expand or override water rights granted by the State Engineer.

Diverting water without a state permit, exceeding adjudicated water rights, or violating curtailment orders may result in enforcement by the State Engineer including fines and loss of priority.