St. Louis County, MN Environmental Rules: Flood Zones (2026)

Section 3.1 applies Ordinance 69 to all land within the county's jurisdiction that falls inside a Special Flood Hazard Area (SFHA) shown on the Flood Insurance Rate Map panels adopted by reference in Section 3.2, all dated March 25, 2025. Section 3.3 splits the SFHA into four overlay districts: the Floodway District (Zone AE areas with a delineated floodway), the Flood Fringe District (Zone AE areas outside the floodway), the General Floodplain District (Zone A or AE areas with no floodway delineated), and the Coastal District (Zone VE and coastal A/AE areas). These overlay standards apply on top of the county's regular zoning, and where they conflict the more restrictive standard controls under Section 3.11.

Section 4.1 requires a permit from the Director before a long list of activities: erecting, adding to, modifying, rehabilitating, repairing, or altering any building or structure; constructing a fence, pool, or deck, or placing anything that could obstruct flood flows (farm fences are exempted); changing or expanding a nonconforming use; repairing flood-, fire-, or tornado-damaged structures; placing fill or excavating; installing utilities or on-site sewage treatment systems; storing materials or equipment; and relocating or altering a watercourse, including new or replacement dams, culverts, and bridges, unless a Department of Natural Resources public waters work permit already covers the disturbance. Section 4.21 sets minimum development standards for anything permitted: structures must be anchored against flotation and lateral movement, built with flood-resistant materials, kept clear of the channel's flood-carrying capacity, and provided with heating, ventilation, and utility equipment elevated to the Regulatory Flood Protection Elevation. County jurisdiction under Section 3.5 covers only unincorporated land; a city annexing floodplain land takes over administration immediately, and a township needs a DNR-approved ordinance and NFIP enrollment before it can take over from the county.