Updated Floodplain Maps Available; Missoula County Provides Resources to Help Residents Understand Changes
Posted on October 21, 2025
For the first time in nearly 50 years, the Federal Emergency Management Agency (FEMA) has released preliminary updated floodplain maps for the Clark Fork River, Bitterroot River and Rock Creek in Missoula County.
Flooding is the most common and the most expensive disaster in the United States, according to FEMA, and the new maps better reflect current flood risks. Missoula County plans to adopt regulations referencing the maps to more effectively regulate development in flood hazard areas in order to minimize flood losses and promote wise use of the floodplain. Regulating development according to the maps also ensures residents remain eligible for federally backed flood insurance through the National Flood Insurance Program (NFIP) and that Missoula County can receive federal assistance in the event of a major flooding disaster.
The floodplain maps were updated using the latest data. Some properties are now shown inside the mapped floodplain while others are newly shown as outside of it, due to the changing nature of rivers and their floodplains.
Missoula County has launched online tools to help property owners understand how the floodplain maps have changed. The preliminary maps are now featured on the County's Property Information System, and staff recorded a video tutorial on how to access and interpret the maps. Property owners can also contact the Missoula County Floodplain Administration Program at 406-258-4657 or email [email protected] for personalized support.
In cases where a property is newly mapped into the floodplain, lenders may require homeowners with mortgages to carry flood insurance. Residents are encouraged to check with their lender or insurance agent, and quotes are available at Floodsmart.gov.
"While Missoula County doesn’t operate a flood insurance program, residents are eligible for a 15% discount on NFIP insurance because the Community Rating System recognizes the County goes above the minimum standards to make our community safer and more resilient," said Matt Heimel, Missoula County floodplain administrator. "Anyone who lives in the county can buy flood insurance and receive this discount."
Building specifications for flood safety and resilience are required in the floodplain. New construction will need a floodplain permit and to meet certain requirements. Examples of these requirements include elevating the structure, using flood-resistant building materials and installing flood vents. For instance, the lowest floor of a new structure typically needs to be elevated two feet above the base flood elevation. Existing legally built structures aren’t required to be modified unless someone plans to alter, substantially improve or replace a structure.
Missoula County will provide updates on the floodplain map process on missoulacountyvoice.com. The County also is planning a series of public open houses for early 2026 in Missoula, Frenchtown, Clinton and Lolo. Dates, times and locations will be announced later this year.
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