Missoula County Floodplain Regulations Update

CLICK HERE for information on the floodplain mapping update for the Clark Fork River, Bitterroot River and Rock Creek

The Federal Emergency Management Agency and Montana Department of Natural Resources and Conservation required Missoula County update the countywide Floodplain Regulations. The amendments included changes to definitions and updates to regulatory language to comply with the DNRC model ordinance. Learn more about DNRC’s floodplain management online. More information is also available on the Missoula County Floodplain Administration website. These updates were required for Missoula County to continue to participate in the National Flood Insurance Program and ensure availability of flood insurance for residents. The updates also ensure the County stays up to date with state and federal regulations and best practices.

In 2022, DNRC updated the state-wide model floodplain ordinance to meet federal regulations and provide regulation clarification. Those updates were sent to Missoula County, and now the County is required to also update floodplain regulations to meet the federal regulations.

DNRC noted the County regulations were not in alignment with federal regulations, specifically in the agricultural section, where it stated certain types of structures, such as a structure solely for agricultural use, may be exempt from elevation requirements under the NFIP. There were also changes to elevation requirements for all accessory structures, various updates to development standards in the flood fringe and floodway, and administrative updates. The County proposed new language in several sections to come to alignment with the state and federal regulations.

The new regulations are a complete reorganization. Most of the information including existing policies and standards remain the same. The draft document marked different sections according to whether they are new required information, or existing higher standards Missoula County already enforces. There were new clarifications including describing when Shaded-X Flood Zones are regulated, how compensatory storage is required, and the aforementioned new elevation requirements for accessory structures. One key example of a more stringent required change is the lowest floor of all accessory structures will be required to be elevated a minimum of two feet above the base flood elevation. Some exemptions will be available for agricultural structures or small structures, such as detached garages, provided the lowest floor is elevated at least to the base flood elevation. That is one example of several technical details, so please let us know if you have any questions or need additional explanation.

County staff held two public review sessions to present key points and answer questions about the amended floodplain regulations. These sessions were on Jan. 23 and Jan. 31.

Missoula County commissioners heard a resolution of intent at their public meeting on Jan. 11, and the final resolution at their public meeting on Feb. 22. Visit the County's Youtube channel to watch the recordings of these meetings.

Find the new regulations under "documents" on the right-hand side, or visit the Floodplain Regulation page on the Missoula County website.