Whenever the supply of water in a stream exceeds the amount required to satisfy all existing appropriations established on or before March 1, 1985, the stream is said to be in an excess flow condition. When excess flows are available during the water year, they may be beneficially used by irrigation water rights holders with priorities dating from March 2, 1945 through March 1, 1985, up to an additional one c.f.s. for each 70 acres irrigated (see W.S. 41-4-329 through W.S. W.S. W.S. 41-4-331 ). Excess water only applies to irrigation water rights that are based on the statutory diversion rate of 1 c.f.s. per 70 acres, and not to volumetric awards made in acre-feet per acre.
037-1 Wyo. Code R. § 1-12