Sioux Falls, SD Environmental Rules: Flood Zones (2026)

Chapter 156 (Floodplain Management) is the City's NFIP-compliance ordinance, with key provisions including: § 156.031 (Basis for Establishing the Areas of Special Flood Hazard) — adopts the FEMA Flood Insurance Study and FIRM panels for Minnehaha County (and incorporated areas) and Lincoln County by reference; § 156.051 (Duties and Responsibilities of the Floodplain Administrator); § 156.065 (General Standards) — requires anchoring against flotation/collapse, flood-resistant materials, and elevation of new/replacement electrical, heating, ventilating, plumbing, and AC service equipment at least two feet above the BFE; and § 156.068 (Floodways) — prohibits any new construction, substantial improvement, or other development within the regulatory floodway unless certified by a registered engineer to cause no increase in flood levels. Sioux Falls exceeds FEMA's minimum NFIP standard (1 foot freeboard) by requiring two feet of freeboard above the BFE for the lowest floor of residential structures and for service equipment. Since August 25, 2016, additional setback rules apply to lots within 100 feet of the regulated floodplain. Floodplain permits are reviewed by the City Planning and Development Services Department; an Elevation Certificate is required for new construction in the SFHA. The Big Sioux River, Skunk Creek, and several tributaries are the primary flood-hazard waterways within city limits.