Section 41-12-205 - Allocation of waters(a) Wyoming and South Dakota agree that the unappropriated waters of the Belle Fourche River as of the date of this compact shall be allocated to each state as follows: Ninety percent (90%) to South Dakota Ten percent (10%) to Wyoming; provided, that allocations to Wyoming shall be exclusive of the use of these waters for domestic and stock use, and Wyoming shall be allowed unrestricted use for these purposes, except that no reservoir for such use shall exceed twenty (20) acre-feet in capacity. For storage of its allocated water, Wyoming shall have the privilege of purchasing at cost not to exceed ten percent (10%) of the total storage capacity for any reservoir or reservoirs constructed in Wyoming for irrigation of lands in South Dakota, or may construct reservoirs itself for the purpose of utilizing such water. Either state may temporarily divert, or store for beneficial use, any unused part of the above percentages allotted to the other, but no continuing right shall be established thereby. (b) Rights to the use of the waters of the Belle Fourche River, whether based on direct diversion or storage, are hereby recognized as of the date of this compact to the extent these rights are valid under the law of the state in which the use is made, and shall remain unimpaired hereby. These rights, together with the additional allocations made under (a) of this section, are agreed to be an equitable apportionment between the states of the waters of the basin. (c) The waters allocated under subsection (a) of this section and the rights recognized under subsection (b) of this section are hereinafter referred to collectively as the apportioned water. For the purposes of the administration of this compact and determining the apportioned water at any given date within a given calendar year, there shall be taken the sum of: (i) The quantity of water in acre-feet that passed the Wyoming-South Dakota state line during the period from January 1 of that year to that given date; (ii) The quantity of water in acre-feet in storage on that date in all reservoirs built in Wyoming on the Belle Fourche River subsequent to the date of this compact.