From email from Reclamation (Peter Soeth):
All the runoff is receding in the upper Colorado River and it is allowing the releases from Granby Reservoir to be lowered.
The spillway gates are being closed at Granby and will be slowing releases through the outlet works.
The current releases are:
Currently moving 550 cfs through the Adams Tunnel to the east slope.
Releases from Lake Granby are currently 431 cfs.
Releases from Willow Creek Reservoir are 109 cfs.
From CBS Denver:
It doesn’t happen every year, but Lake Granby’s overflow spillway is a sight to see.
Water gushes from 320 feet in the air, out of the lake and into the headwater of the Colorado River. Water was flowing at 800 cubic feet per second as of Friday afternoon. The big wave at the base of the fall is caused by massive concrete blocks.
The big spill means Lake Granby — the water body that supplies Fort Collins, Greeley and Boulder — is full. Water experts say that because they’re able to do this spill it will be a good water year for Colorado.
“This signals that there’s still a lot of water, a lot of snowpack up in Rocky Mountain National Park that’s coming into our reservoirs and we don’t have enough room to capture it all. So good water year, we’re smiling in the water business today,” said Brian Werner of Northern Water.
Water pouring down the spillway will eventually end up in Lake Powell.