Coal Creek Flood Mitigation Facility

This project, which is now complete, mitigates flooding from Coal Creek (from the Clark Reservoir Inlet Canal [¼ mile south of County Road 70]) south through the Town of Wellington as far south as the confluence of Coal Creek and Boxelder Creek.

The purpose of the project was to protect approximately 200 homes, dozens of businesses, and two schools within the Coal Creek floodplain in the Town of Wellington. This $5.1M project diverts stormwater flows from Coal Creek (which is tributary to Boxelder Creek) into the Clark Reservoir Inlet Canal and ultimately into Clark Reservoir. North Poudre Irrigation Company (NPIC) owns these facilities, which are north of the Town of Wellington. Funding for this project came from a FEMA Pre-Disaster Mitigation Grant (PDM), matching funds, and Authority Service Fees.

The elements of the project included the following:

  • Improvement of the Clark Reservoir Inlet Canal to capture and convey 100-year Coal Creek flood flows (1,700cfs) into the existing Clark Reservoir.
  • Culvert and bridge crossings associated with the Inlet Canal.
  • Removal of sediment (186,000CY) from Clark Reservoir to provide volume to store irrigation water and some flood water.
  • Associated right-of-way acquisition.
  • Spillway improvements to Clark Reservoir to provide additional flood storage volume.
  • Raising the emergency spillway provides the 540 acre-feet of flood storage along with the 871 acre-feet of decreed storage for NPIC.
  • Agreement between North Poudre Irrigation Company and Boxelder Stormwater Authority regarding maintenance of improvements.
  • Reconstruction of the County Road 7 bridge over Inlet Canal.


 

Inlet Canal

 

Clark Reservoir

 

Regional Benefits:

This project provides regional flood hazard mitigation when combined with the East Side Detention Facility (ESDF).

 

Local Benefits:

The Coal Creek Flood Mitigation Project removed flood hazard designation from most of the designated properties in the Town of Wellington and north of Wellington along Coal Creek. It reduced the acreage designated by FEMA as a floodplain by approximately 700 to 850 acres. It also reduced the flood hazard and damages for approximately 200 homes, dozens of businesses, and two schools, a community center, and commercial structures. A Letter of Map Revision (LOMR) was filed with FEMA and approved in February 2013.