Montana Floodplain Management Statewide Requirements

Under MCA 76-5-101 et seq., Montana requires every community participating in the National Flood Insurance Program to adopt floodplain regulations approved by the Department of Natural Resources and Conservation (DNRC). State law establishes minimum standards for development in mapped 100-year floodplains: residential structures must be elevated above the base flood elevation, and certain uses (like hospitals or storage of toxic materials) are prohibited in the floodway. Municipalities and counties administer permits but cannot adopt regulations less restrictive than DNRC rules. Permits are required before construction, fill, or substantial improvements within mapped floodplains.

Construction without a floodplain permit may result in civil penalties up to $500 per day, mandatory removal, and loss of NFIP flood insurance eligibility for the property.