Richland County, Sidney, and Fairview are working with MT DNRC and FEMA to update and produce new Flood Insurance Rate Maps (FIRMS) for the Yellowstone River Tributaries and the Missouri River and Tributaries through the county. The Yellowstone River will not be apart of this study as it was recently studied in 2019. Updated floodplain maps will depict the latest, most accurate flood risk data, and will eventually replace the existing floodplain maps.

DNRC held project kick off meetings with all the communities September 21, 2022.

As work progresses updates will be made to this website. 

History of Floodplain Maps:

Flood Hazard Boundary maps were initially produced for Richland County in 1978, the City of Sidney in 1975, and the Town of Fairview in 1974. The first detailed flood study was conducted on Lone Tree Creek in 1985 for Richland County and the City of Sidney. Lone Tree Creek runs through the City of Sidney and has caused flooding concerns. 

In 2007, Richland County went through Map Modernization to incorporate a 1986 detailed study on the Missouri River from the Fort Peck Assiniboine and Sioux Tribes and convert the remaining existing paper FIRMs in the county to digital format.  In 2008 a Letter of Map Revision (LOMR) was issued for a portion of Lone Tree Creek for bridge and channelization work.

in 2015 Richland County worked with MT DNRC  to initiate a detailed study on the Yellowstone River. The resulting 2019 Physical Map Revision (PMR) updated 25 FIRM panels along the Yellowstone River corridor.   

2022 Flood Study:

This project will conduct new floodplain mapping studies on the remaining mapped floodplains in the county, including 6.3 miles of the enhanced with floodway tributaries, 157.3 miles of enhanced tributaries, 24.2 shoreline miles of mapped water bodies, and 241.5 miles of BLE. Including new field survey, base map preparation, hydrologic and hydraulic analyses, and floodplain mapping.    

Tentative project timeline: