07012020 - RFP for Colorado River Connectivity Channel (CRCC) at Windy Gap - CM/GC Services

The Windy Gap Water Activity Enterprise (the “Enterprise”), a government-owned business within the meaning of Article X § 20(2)(d) of the Colorado Constitution, organized pursuant to C.R.S. §§ 37-45.1- 101 et seq., owned by the Municipal Subdistrict, Northern Colorado Water Conservancy District (the “Subdistrict”), is requesting proposals from qualified firms to act as the Construction Manager/General Contractor (CM/GC) on the Colorado River Connectivity Channel (CRCC) project.   The selected CM/GC firm will assist on the pre-construction, constructability review, and construction management/general construction of the approximately $17 million-dollar CRCC project in Grand County CO.  

The purpose of the Colorado River Connectivity Channel (CRCC) project is to reconfigure Windy Gap Reservoir so that a naturally-functioning connecting channel can be constructed that will allow fish passage, downstream bedload sediment transport, and public fishing access along most of the new channel. The project includes the following main elements:

1. Modified embankment of the Windy Gap dam. A new southern embankment constructed north of, and roughly parallel to, the existing embankment to create a modified reservoir with a smaller surface area. This will provide an area for the new channel and floodplain to be constructed. To compensate for reduced reservoir storage, the low block section of the spillway will be raised 1 foot, to match the elevation of rest of the spillway.
2. A new diversion structure that allows flows to be directed between the reservoir and new connectivity channel. The structure will have a capacity of at least 600 cfs to allow sufficient flow into the reconfigured reservoir for meeting pumping requirements when Windy Gap water rights are in priority, while also maintaining sediment transport and fish passage down the new channel.
3. A new connectivity channel and floodplain that connects the Colorado River above and below the reconfigured reservoir. The new channel and floodplain will be constructed in a manner that allows for natural geomorphic and ecological river processes to take place to the extent practicable while maintaining dam safety, including some channel migration, activation (flooding) of the floodplain, and hyporheic flow through the channel substrates. Sediment shall be managed within the channel such that net aggradation and degradation is balanced while allowing bedload gravels and cobbles to move downstream to improve the aquatic habitat quality and trout fishery in the reach of the Colorado River downstream of Windy Gap. The channel shall provide fish passage for both sportfish (trout) and native fish (mottled sculpin). 
4. Improvements to the Fraser River stream gauge immediately upstream of Windy Gap Reservoir to facilitate fish passage while maintaining flow monitoring functionality.