Colorado River Connectivity Channel

A New Channel for Fish and Sediment Passage

As part of the Windy Gap Firming Project’s permitting phase to build Chimney Hollow Reservoir, the historical impacts of the original Windy Gap Project were also evaluated, including the loss of river connectivity following construction of the Windy Gap Reservoir dam on the Colorado River. To minimize the dam’s impact on aquatic habitat and species, the Municipal Subdistrict, which owns and operates the Windy Gap Project, agreed to decrease the reservoir’s footprint and construct a connecting channel around the reservoir capable of passing water, fish and sediment, thereby reconnecting miles of the Upper Colorado and Fraser rivers.  

Colorado River Connectivity Channel Fact Sheet
Aerial view of Windy Gap Reservoir where the connectivity channel will be constructed.

The Colorado River Connectivity Channel project, which will also allow public access for fishing along most of the new channel, includes:  

  • Windy Gap Dam Embankment Modification - A new southern embankment will create a smaller reservoir and provide space to construct the new channel and floodplain. The spillway will also be modified to compensate for reduced reservoir storage. 
  • Diversion Structure - A new diversion structure will allow river flows to be diverted between the reservoir and new connectivity channel. The structure will allow sufficient flow into the reconfigured reservoir to meet pumping requirements when the Windy Gap Project’s water rights are in priority, while also maintaining downstream transport of water, sediment and the passage of fish.  
  • Connectivity Channel - A new channel and floodplain will connect the Colorado River above and below the reconfigured reservoir. To the extent possible, the new channel and floodplain will allow natural geomorphic and ecological river processes to take place while maintaining dam safety.   
  • Fraser Stream Gage Retrofit - Improvements to the Fraser River stream gauge immediately upstream of Windy Gap Reservoir will facilitate fish passage. 
Project Partnerships

Multiple invested stakeholders are assisting to ensure a successful connectivity channel project. Stakeholder contributions include design, project management, fund raising and time. The Municipal Subdistrict and Trout Unlimited contracted with AECOM to conduct the final design. Other project partners include Colorado Parks and Wildlife, Colorado Water Conservation Board, Grand County, the Colorado River District and the Upper Colorado River Alliance.

Project Status

A formal Draft Plan-EA public review period was performed for the project from Feb. 8 to March 10, 2022. NRCS has completed the Final Plan-EA for the project and issued a Finding of No Significant Impact (FONSI). Electronic versions of the documents may be downloaded on the NRCS website.

According to Executive Order 11988 and NRCS NEPA regulations, a 30-day public review period will be opened for the project since it is located in a wetland and floodplain. The public review period will end on June 8, 2022.