S.D. Codified Laws § 5-18C-4
If a municipality requires a developer to install water, sanitary sewer, and storm sewer trunk lines or mains; sewer collection systems; or streets at the expense of the developer and the municipality requires the size of the trunk line or main, sewer collection systems, or streets to be larger than the developer's requirements, the price difference paid by the municipality and as determined by a licensed engineer's estimate is exempt from the provisions of this chapter and chapters 5-18A, 5-18B, and 5-18D.
If a developer installs a regional storm sewer detention pond ahead of a municipality's schedule at the expense of the developer, the price of the pond construction paid by the municipality and based on certified quantities provided by a licensed engineer is exempt from the provisions of this chapter and chapters 5-18A, 5-18B, and 5-18D.
SDCL 5-18C-4