French Creek flood mitigation site up

In 2019, severe rainfall led to flash flooding along French Creek, sending water into streets, homes and businesses through the City of Custer. The event caused widespread disruptions and highlighted how quickly conditions along the creek can become hazardous.
Building on several years of previous flood-study work, RESPEC Engineering has helped the city better understand where flooding occurs, how water moves through the community, and what mitigation options could reduce future impacts. In 2023, most of Custer County was designated as a Community Disaster Resilience Zone, underscoring the importance of continued efforts to strengthen long-term flood preparedness and resilience.
In 2023, Custer County, Headwaters Economics, and RESPEC partnered to launch the French Creek Flood Study, leading to a watershed-wide hydraulic structure inventory, updated flow frequency estimates and development of a 2D hydraulic model capable of showing where and how floodwaters move. This work identified several priority areas, such as places where roads overtop, neighborhoods flood and critical access routes fail during large flood events. 
At the website sto
rymaps.arcgis.com/sto
ries/2ce9978ca0d84b88bdb95726176d79fa a video provides a view of the updated 2D hydraulic model, highlighting its ability to capture complex flow patterns that were not represented in the original 1D model.
With the momentum of the Federal Emergency Management Agency’s (FEMA) Building Resilient Infrastructure and Communities (BRIC) funded French Creek Flood Mitigation project now underway, the community has a clearer understanding of existing flood risks. The alternatives presented in this website represent the next steps forward: data-driven, community-guided designs that can reduce damage, protect access and build a more resilient future for everyone who lives, works, and visits Custer.
The upcoming phases will identify and refine a preferred flood mitigation project that:
• Reflects community needs and values
• Advances toward 60 percent design readiness
• Meets FEMA’s benefit-cost analysis standards to qualify for future construction funding
Project Phases
• Project prioritization
• Benefit-cost analysis
• Thirty percent design
• Environmental permitting
• Sixty percent design
• Construction grant application development     
Community engagement
A community-wide meeting will be scheduled to share updates, discuss potential mitigation concepts and gather input. 
This website will be updated throughout the project. Check back for meeting details and new content. Complete the  community survey  which helps guide project priorities. 
Schedule
Substantial progress will continue through 2026, but the volume of work still ahead may challenge the team’s ability to meet the fall 2026 FEMA construction grant application deadline. Even so, achieving substantial completion within this period remains a project goal.