Wyo. Stat. § 41-3-113
A supplemental supply water right is defined as a permit or certificate of appropriation for the diversion, from a stream, of water from a new source of supply for application to lands for which an appropriation of water from a primary source already exists. Such supplemental supply permits or certificates of appropriation may be allowed by the state engineer or the state board of control under such regulations or conditions as he or it may prescribe. The use and administration of presently existing rights for supplemental supply appropriations or rights for supplemental supply appropriations hereafter acquired shall hereafter be made upon the express condition that the total amount of water to be diverted at any one (1) time both under a primary appropriation of water and a supplemental supply appropriation shall not be in excess of one (1) cubic foot of water per second of time for each seventy (70) acre tract so irrigated, except that when the right to divert water under the provisions of W.S. 41-4-317 through 41-4-324, is permitted the total amount of surplus water to be diverted at any one (1) time both under a primary appropriation of water and a supplemental supply appropriation shall not be in excess of one (1) cubic foot of water per second for each seventy (70) acre tract so irrigated. Nothing herein shall be construed to apply to water stored under a reservoir permit.
W.S. 41-3-113