West Slope Water Collection

The Colorado-Big Thompson Project West Slope collection system stores upper Colorado River watershed runoff in several reservoirs before transporting it to the East Slope through the Alva B. Adams Tunnel. The collection system consists of three reservoirs, a natural lake, two pumping plants, canals and control and measurement facilities.

The North Fork of the Colorado River enters the C-BT Project collection system on the west side of Shadow Mountain Reservoir. The Colorado River flows from Shadow Mountain to Lake Granby, and exits the southwest side of the lake at Granby Dam.

Water from the C-BT Project is delivered to Colorado’s East Slope and Eastern Plains through the 13.1-mile Alva B. Adams Tunnel, which begins at Grand Lake and extends under the Continental Divide and Rocky Mountain National Park.