Pumping at Animas-La Plata Project Underway - Lake
Nighthorse Filling

Water pumped from Animas River being
discharged from outlet at 280 cfs

At approximately 2:00 pm on Thursday, June 4, Reclamation’s Four Corners Construction Office (FCCO) began pumping from the Durango Pumping Plant into Lake Nighthorse at full capacity which is 280+/- cubic fee per second (cfs). Currently, reservoir storage is estimated at approximately 28,000 acre feet which includes water pumped at lower capacity, water pumped during the testing phase, and water stored from precipitation events. Beginning June 8, FCCO initiated 24-hour/7 days per week monitoring of the performance of Ridges Basin Dam and associated features. To date, all instrumentation and visual inspections have met or exceeded expected performance parameters. 

The rate at which Lake Nighthorse will fill depends on a number of factors including  river hydrology, power costs, unit availability, minimum bypass requirements for the Animas River, performance of the dam and appurtenant features, holding periods, and other factors. The estimated time to fill the reservoir to capacity ranges from one year to five years depending on the above factors. If river hydrology remains near historical averages, and the other variables remain within the expected parameters, it is reasonable to expect Lake Nighthorse to reach its 120,000 acre-foot capacity in approximately 18 months.