Water Projects

The Colorado-Big Thompson Project supplies water to more than 640,000 acres of irrigated farm and ranch land and 925,000 people in Northeastern Colorado. Northern Water’s boundaries include portions of eight counties and encompass approximately 1.6 million acres. Besides collecting and delivering water, the C-BT Project provides clean hydroelectricity and numerous recreational opportunities.

Shadow Mountain ReservoirShadow Mountain Reservoir
Shadow Mountain Reservoir on Colorado’s West Slope is part of
the Colorado-Big Thompson Project.

Water Systems Map
Colorado-Big Thompson Project Map
C-BT & Windy Gap Project Statistics

Colorado-Big Thompson Project

The C-BT Project collects supplemental water on the West Slope and delivers it to East Slope water users via 12 reservoirs, 35 miles of tunnels and 95 miles of canals. Learn more»

Windy Gap Project

The Windy Gap Project consists of a diversion dam and pump plant on the Colorado River and a 6-mile pipeline to Lake Granby. From there, C-BT facilities transport water to the East Slope. Learn more»

Proposed Projects

The proposed Northern Integrated Supply Project and the Windy Gap Firming Project would provide additional water for population growth while lessening the impacts of growth on agricultural water supplies. Learn more»

Pipelines & Outlets

The Pleasant Valley Pipeline carries water from the Poudre River and Horsetooth Reservoir to three treatment plants. The Southern Water Supply Pipeline and the Carter Lake Outlet deliver water year-round to municipal, domestic and industrial water users. Learn more»
2013 Flood
Find updates on C-BT facilities affected by the September 2013 Flood. Learn more»
Environmental Stewardship
C-BT Project power plants generate an average of 760 million kilowatt hours of clean hydropower each year, and Northern Water is helping restore endangered species habitat in the Platte River and Upper Colorado River basins. Learn more»
Water Data
View and download real-time streamflow and reservoir level information and current snowpack data for the C-BT and Windy Gap projects on both sides of the Continental Divide. Learn more»

Map Gallery

View and print maps, including the C-BT and Windy Gap projects, pipeline routes, weather and water data sites, and Northern Water and Municipal Subdistrict boundaries. Learn more»