037-10 Wyo. Code R. § 10-2
a. The most important provision of this law is chat storage of direct flow rights must be accomplished without injuring or affecting any other Wyoming appropriator. In order to determine if such storage can be accomplished without injury and to allow proper administration of the proposal, certain information must be furnished. It should be understood that (1) at certain times and under certain conditions in some areas, it may be possible to store the entire amount of the direct flow appropriation, (2) at other times only a portion of that right may be stored, and finally (3) at other times and in some areas no water may be stored. This will depend on. the past historical use Of the direct flow rights, what other rights divert or store water from the same source of supply and how they might be affected by the proposed storage.
b. A direct flow right proposed to be stored must be a valid right which is in use and has been in use for at least the preceding five (5) year period. The five year period is necessary in order to establish the pattern of historic use under the right.
c. In determining if storage can be allowed, and if so, the amount of storage, several factors will be considered. If, for example, the pro* posed storage is on a stream drainage where such storage would not interfere with any other appropriators, junior or senior in priority, storage may be allowed up to the full amount of the appropriation as long as interference does not occur with other rights. If, however, storage is proposed on a stream drainage which is heavily appropriated both for storage and for direct flow appropriations, then such storage may not be allowed or may be restricted in quantity and in time of storage. In such circumstance, the amount of storage may be limited to the amount of water determined to have been consumed in growing the plant and lost through evaporation and transpiration. The amount of this consumptive use would be determined from past records of diversion and such factors as the type of irrigation practiced, the slope of the land, the type of plant irrigated, soil type and weather pattern. Storage of the consumptive use portion of a right will be restricted to the time during which water has been historically used in the past for irrigation. Water cannot be stored under a direct flow right when such right is not in priority and, therefore, not entitled to water. It would not be permissible to divert water under a direct flow right and store water under the same right, at the same time.
Storage of the consumptive use portion of a right must be coincidental with the Lime period that such right has been exercised in the past.
037-10 Wyo. Code R. § 10-2