S.D. Codified Laws § 46A-1-12
The Board of Water and Natural Resources shall make a comprehensive evaluation and allocation of the comparative benefits and costs of all water facilities included in the State Water Resources Management System among and between the various levels of government and private interests in accordance with § 46A-2-3. Its recommendations shall include with respect to each such facility the amount or amounts to be shared by each and every level of beneficial user and may provide that the state's share will be apportioned over a period of years and may be funded by appropriations or as may otherwise be provided. These benefit-cost ratios shall be set forth in detail.
The board shall formulate and determine the priority or priorities of any or all such facilities and the sufficient financing thereof.
SDCL 46A-1-12