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DNRC Headquarters
1539 Eleventh Ave. Helena, MT 59601
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Jefferson County Flood Maps Update

Jefferson County has been working with the Federal Emergency Management Agency (FEMA) and Montana Department of Natural Resources and Conservation (DNRC) to produce updated 100-year floodplain maps.  The project includes updating all the existing mapped floodplains in the county, and producing new floodplain maps for portions of Prickly Pear Creek and tributaries in the northern part of the county.  View study 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 in Jefferson County are based off of data from the 1970s.

New floodplain maps from this project are not expected to be finalized for a while – the study information and maps need to go through a lengthy technical and public review process.  When finalized, new maps could have effects on some property owners in mapped 100-year floodplains. See: 100 year Floodplain Fact Sheet.

View Draft Data

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

Jefferson River - Hydrology Analysis
Boulder R & Prickly Pear Cr mainstems & tributaries; and Jefferson R tributaries - Hydrology Analysis

More draft data and information will be posted as it becomes available.

Come back for more information

We will update this website with new, relevant information as it is available.

Know your property's flood risk

Flood Insurance Rate Maps indicate areas of flood risk. Once this project is complete, updated Flood Insurance Rate Maps will provide more accurate, current, and detailed data and mapping of flood risk areas.

Project Timeline

Project Timeline Jefferson Floodplain Maps Update.png



Bureau Chief
Water Operations Bureau
(406) 444-6816

NFIP/CAP Coordinator
(406) 444-6654

Tiffany Lyden, CFM
Outreach Specialist
(406) 444-0599

Floodplain Specialist
(406) 444-1343 

(Shaye will be back January 2022)

Civil Engineering Specialist
(406) 444-1300

Outreach Specialist
(406) 444-6732

Flood Hazard GIS Specialist
(406) 444-6664

Floodplain Mapping Specialist
(406) 444-6656