Granby Dam (National ID # CO01656) is an earthfill dam that dams the Colorado River northeast of Granby, Colorado in Grand County, Colorado. This -tall dam was constructed between 1941 and 1950 and has a drainage area of . The Granby Dam's reservoir is known as Lake Granby, the largest reservoir component of the Colorado-Big Thompson Project. Lake Granby stores Colorado River water that is diverted under the Continental Divide for agriculture and municipal use within north-eastern Colorado including the cities of Boulder, Fort Collins, Loveland, and Greeley. In addition to the waters of the Colorado, water from Willow Creek just below the dam is pumped up to Lake Granby. Water from Lake Granby is pumped higher by the Granby Pumping Plant to the Granby Pump Canal, which extents to Shadow Mountain Lake, from which water is diverted through the Alva B. Adams Tunnel to the East Slope. This damsite does not generate any power directly; power is generated at other locations in the Colorado-Big Thompson Project. References External links USBR Granby Dam Website Dams on the Colorado River Dams in Colorado Buildings and structures in Grand County, Colorado United States Bureau of Reclamation dams Dams completed in 1950 Earth-filled dams