Granby Reservoir set to fill and spill
May 27, 2016
Memorial Day weekend is a time for remembrance, a time to reflect on the sacrifices of those who have borne the battle for the United States over the last 240 years.
The weekend also serves as a sort of unofficial kickoff for the summer season. Very soon the lakes and reservoirs of Grand County will become much busier as anglers, boaters, jet skiers and others looking to recreate on the waters of Middle Park begin heading out for the summer.
Things look to be shaping up nicely in terms of water levels for 2016. The Colorado River District recently hosted a "Grand County State of the River" meeting at Mountain Parks Electric in Granby. During the meeting representatives from the Federal Bureau of Reclamation informed attendees their prediction models indicate Granby Reservoir will physically fill again this year, sometime around the second week of July at which point those administering the water flows will begin bypassing additional water downstream.
Officials expect the massive reservoir to spill slightly, around 1,700 acre-feet of water, right at maximum flow times. Bureau of Reclamation representatives said that if Granby does spill they anticipate moving the excess water through the outlet works for the reservoir's dam.
So far 2016 has been a fairly average year in terms of precipitation. Reservoirs along the eastern slope of the continental divide are mostly full and transmountain diversions will likely be diminished because of storage levels in places like Horsetooth and Carter Lake Reservoirs.
Willow Creek Reservoir, a relatively small reservoir located just a few miles directly west of Granby Reservoir has seen high levels of runoff already and officials anticipate pumping roughly 40,000 acre-feet of water from Willow Creek into Granby Reservoir this summer. Because of storage limits water from Willow Creek Reservoir is already being bypassed downstream.
Because of the high water levels anticipated for Willow Creek Reservoir and the rest of the Three Lakes Colorado River Collection System officials do not expect to pump any water up from the Windy Gap Reservoir, located west of Granby on US Highway 40 and downstream from Granby Reservoir.
Existing directives from the US Secretary of the Interior require at least 75 cubic feet per second (cfs) of water be released from Granby Reservoir throughout the summer. The Bureau of Reclamation will maintain releases of 75 cfs from Granby Reservoir through October this year as part of the ongoing Upper Colorado River Endangered Fish Recovery Program.