Madison, Jefferson, Gallatin, and Broadwater Counties have been working with the Federal Emergency Management Agency (FEMA) and Montana Department of Natural Resources and Conservation (DNRC) to produce new floodplain maps for portions of the Madison, Ruby, Jefferson, Beaverhead and South Boulder Rivers, and Mill and Indian Creeks.

See project extents here.

Updated floodplain maps will depict the latest, most accurate flood risk data, and will eventually result in updated FEMA floodplain maps. Most of the existing FEMA floodplain maps and Madison County flood prone maps are based on data from the 1980s and 1990s. 

To understand what goes into a new floodplain study click here.

View Draft Data

New floodplain maps from this project are not expected to be finalized for a while – draft maps will be available to start reviewing in late 2020, but the study and maps will need to go through a lengthy technical and public review process before they can be finalized. When finalized, new maps could have effects on some property owners in the mapped 100-year floodplains. 

New floodplain studies involve collecting and analyzing data, including: topography, hydrology analyses and hydraulic analyses.  

You can also view individual draft maps here:
View draft floodplain maps

Get more information on floodplain designations referenced on the maps, community meetings, and important information:

Newly Mapped into a 100-Year Floodplain? See Low Cost Insurance Options 

Big Hole River Floodplain Maps

A flood study and floodplain maps for the Big Hole River were produced in 2015. The Big Hole River floodplain maps and study information will eventually be incorporated into preliminary FEMA floodplain maps at the same time as the rest of Madison County's draft floodplain maps.  Preliminary FEMA floodplain maps will go through a public review process before they are finalized.  

Attend a public open house meeting

Gallatin County & City of Three Forks

• December 2, 2020 @ 6pm - Three Forks floodplain mapping and mitigation meeting.  To register for this virtual meeting: click here.
• January 6, 2021 - Three Forks Draft floodplain map public open house event.  Please check back for more information on how to register for this event.

Madison County & Towns of Ennis, Twin Bridges, Sheridan

• Please check back for more information

Jefferson & Broadwater County

• Please check back for more information

Know your property's flood risk

Floodplain maps indicate areas of flood risk. Once this project is complete, updated flood risk information  will be reflected on new and updated FEMA Flood Insurance Rate Maps.  These maps will provide more accurate, current, and detailed information about flood risk areas.

Project Timeline