S.D. Codified Laws § 46-7-5.3
Upon petition to the board by the owner of a dam, the chief engineer may investigate and conduct the necessary analysis to determine the potential for damage to downstream residents or property if a dam were to fail due to inadequate spillway capacity. After the investigation and analysis, the chief engineer may recommend that a variance to board rules relating to minimum spillway design requirements for dams be granted or denied. The recommendation, notice, and hearing before the board shall be conducted pursuant to the procedure contained in chapter 46-2A. Following the hearing, the board may grant a variance upon a finding that failure of the dam due to inadequate spillway capacity will not increase the potential for damage from flooding to downstream residents or property.
SDCL 46-7-5.3