Minnehaha County, SD Environmental Rules: Flood Zones (2026)

Minnehaha County (CID 460059) is an NFIP participating community and adopts a Floodplain Management Ordinance under the authority of SDCL Chapter 11-2 (county zoning) and SDCL Chapter 46A-10A (flood control) to satisfy the minimum NFIP standards in 44 CFR § 60.3. Within Special Flood Hazard Areas (Zone A and Zone AE on the effective FEMA FIRM panels), a Floodplain Development Permit is required before any construction, substantial improvement, fill, grading, or placement of a manufactured home. New residential structures within the SFHA must have the lowest floor (including basement) elevated to or above the Base Flood Elevation (BFE); Minnehaha County requires a freeboard above the BFE consistent with the State Model Floodplain Ordinance promoted by SD DANR. Non-residential structures may be elevated or dry-floodproofed to the BFE. Substantial improvement or substantial damage (cumulative cost 50% or more of pre-improvement market value) triggers full NFIP compliance for the entire structure. The Floodway (the channel and adjacent area reserved to convey the base flood without raising the water surface more than one foot) is subject to a no-rise standard — no encroachment that increases base flood elevation is permitted (44 CFR 60.3(d)(3)). The Big Sioux River corridor through Renner, Brandon, and Dell Rapids is the dominant flood hazard; Skunk Creek and Split Rock Creek add localized SFHAs. The City of Sioux Falls administers its own ordinance within city limits. Property owners can find their flood zone on the FEMA Flood Map Service Center at msc.fema.gov.