From the Estes Park Trail-Gazette (John Cordsen):
The bureau stopped diverting water through the Adams Tunnel into the lake on Nov. 5, as well as moving water from Lake Estes through the Olympus Tunnel to the southern power arm of the Colorado-Big Thompson water diversion, storage and delivery project, of which Estes, Marys and East Portal are a part. This was in preparation for some regular maintenance projects on that section.
Water that would normally hit the three power plants between Lake Estes and the mouth of the Big Thompson Canyon was instead released directly from Olympus Dam to the Big Thompson River. That bumped flows in the canyon up to around 150 cubic feet per second where they stayed for about a week.
“With the 150 cfs being released from Lake Estes, but no water coming in, the water level elevation at Estes dropped a little over a foot a day until it reached the elevation it is currently at now: 7460 feet, or about 15 feet down from full,” said Kara Lamb, the Bureau of Reclamation public information officer. “Then, we curtailed the releases back to native inflow and are now holding steady. Our plan is to keep Lake Estes at this elevation until mid-December.”
Lamb said the bureau, the agency that manages the lake, drops the water level down to this elevation every two to three years for regular maintenance projects.
More Colorado-Big Thompson Project coverage here.