Colorado-Big Thompson Project Positioned for Water Delivery Season

Through the winter months, the Colorado-Big Thompson (C-BT) Project focuses on filling reservoirs for the upcoming water year and generating hydropower. At this time of year, the Alva B. Adams Tunnel, which diverts water under Rocky Mountain National Park from the West Slope to Northeastern Colorado, is operating at a full 550 cubic feet per second (cfs) sending water to Carter Lake and Horsetooth Reservoir. Both Carter and Horsetooth will reach capacity by late spring or early summer.  

“In the summer, demand for water outpaces Northern Water’s ability to fill reservoirs back up, which is normal for reservoirs in the West,” said Water Resources Engineer Brian Craig. “We use the winters to fill and stage them for summer when demands outpace the ability to fill again.”  

With all the water movement during winter, the C-BT Project produces a lot of energy through its six hydropower plants. The C-BT Project’s six original power plants generate power as the water moves through the system on its way to customers in Northeastern Colorado. Power is generated by water flowing through power plant turbines to produce hydroelectricity. The U.B. Bureau of Reclamation, the federal partner for the project, operates and maintains the hydropower plants.