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 four 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.