B-849R

Wyoming Water Law

By James Jacobs, Agricultural Experiment Station,

Patrick Tyrrell, state engineer’s office, and

Donald Brosz, Cooperative Extension Service

Water regulations in Wyoming date back to territorial days and are based on the “doctrine of prior appropriation.” Under this doctrine, the first person to put the water to beneficial use has the first right, meaning “first in time is first in right.” Those with the earliest rights are entitled to water during periods of limited supply while those with later rights are denied water during such times.

Wyoming Water Law explains the background and components of the state’s water law and how it operates today. A valid right to the use of water may be acquired only by following the procedures established by state law for both surface water and groundwater.