The Colorado-Big Thompson Project (C-BT) collects, stores and delivers more than 200,000 acre-feet of supplemental water each year. Nearly all of the project’s water comes from snowmelt in the Upper Colorado River basin, located in Rocky Mountain National Park and Grand County. Snowmelt is stored in Lake Granby – the state’s second largest water body – as well as water collected in Willow Creek Reservoir. From Lake Granby, water is lifted by Farr Pump Plant into the Granby Pump Canal feeding Shadow Mountain Reservoir and Grand Lake. Water then flows from Grand Lake into the West Portal of the 13.1-mile Alva B. Adams Tunnel. Once water exits the tunnel’s East Portal, it descends the Front Range mountains nearly 2,600 vertical feet and passes through five power plants and four reservoirs. The water is supplied to approximately 1,021,000 million residents and 615,000 acres of irrigated farmland in Northeastern Colorado. This federally-owned project is jointly operated, maintained and funded by the U.S. Bureau of Reclamation and Northern Water. Learn more at www.northernwater.org/what-we-do/deliver-water/colorado-big-thompson-project.
Below is a collection of documents related to the Colorado-Big Thompson Project (including water quality and clarity):