Carter Lake is the second largest reservoir in the Colorado-Big Thompson Project East Slope distribution system and the principal reservoir for C-BT Project deliveries to the south and east. Carter Lake’s water originates in the headwaters of the Colorado River in the C-BT Project’s West Slope Collection System.
Several cities, including Longmont, Boulder and Broomfield, receive water from Carter Lake. The lake's water also irrigates farms and ranches in Boulder and Weld counties.
Water Delivered to Front Range, Eastern Plains The Southern Water Supply Project pipeline carries water from Carter Lake south to Broomfield, Louisville and Superior. The pipeline also stretches east to Fort Lupton, Hudson and Fort Morgan on the Eastern Plains.
C-BT Project water is pumped 300 feet from Flatiron Reservoir through the 1.4-mile long Carter Lake Pressure Tunnel to Carter Lake.
Carter Lake Recreation Carter Lake is a popular recreational site for fishing, camping, sailing, waterskiing and swimming. The lake is surrounded by 1,000 acres of public land. For more information, see the C-BT Recreation - East Slope page.
Carter Lake construction began in July 1950, was completed in September 1952 and cost $3.7 million. Carter Lake has a capacity of 112,230 acre-feet of water, 1,110 surface acres, 12 miles of shoreline and its maximum depth is 180 feet.
Power Plant at Carter Lake
The Robert V. Trout Hydropower Plant at Carter Lake started producing power in May 2012. It is expected to produce 7 to 10 million kilowatt-hours of clean energy a year – enough to power about 1,000 homes – sold by the Poudre Valley Rural Electric Association. Learn more about the power plant.