South Dakota state law: ADU impact fees and connection charges

Unlike California (Government Code 65852.2(f)(3) prohibits impact fees on ADUs under 750 sq ft and caps fees proportionally above 750 sq ft) or Colorado (CRS 29-20-104.5 sets a structural impact-fee enabling and limiting framework), South Dakota has NOT enacted a general impact-fee enabling statute or any ADU-specific impact-fee exemption. South Dakota municipalities derive authority to charge water and sewer connection fees from SDCL Chapter 9-48 (water systems) and SDCL Chapter 9-48A (sewer systems), and from utility-rate authority under home-rule charters. Plat-related dedication and improvement requirements are governed by SDCL Chapter 11-3 (Plats and Subdivisions). System-development charges and 'capacity fees' for water and sewer hookup are commonly imposed by South Dakota cities and special districts and may apply at the full single-family-dwelling rate to a new ADU, depending on the local utility's fee schedule. There is no state-mandated nexus-and-proportionality test (contrast Nollan/Dolan as codified in some states) at the South Dakota state-statute level — challenges to ADU impact fees would proceed under the federal constitutional takings doctrine and the South Dakota constitutional inverse-condemnation framework. Because there is no state ADU impact-fee preemption or exemption, ADU fees in South Dakota can be substantial — particularly water/sewer connection charges in cities with growth-driven utility expansion. Check the local utility's fee schedule before construction.

Failure to pay ADU impact, connection, or system-development fees prevents issuance of the building permit and Certificate of Occupancy. Connection without payment exposes the owner to disconnection and civil penalty under the local utility ordinance.