Wyo. Stat. § 41-7-601
The board of commissioners of any irrigation district, in contracting with the United States for the construction, operation and maintenance of its necessary works for the delivery and distribution of water therefrom under the provisions of the federal reclamation act and acts amendatory thereto and supplementary thereof, and the rules and regulations established thereunder, may include in said contract with the United States, a provision or provisions for the construction, operation and maintenance of any necessary drainage works which they may reasonably contemplate to be necessary for the reclamation and drainage of lands of the district affected injuriously by the seepage or percolation of waters from the irrigation works of the district or from the highlands in the district irrigated or to be irrigated, and said commissioners shall include the costs of such drainage in the "cost of construction" as defined by W.S. 41-7-305.
W.S. 41-7-601