Good Afternoon,

 

To accommodate required California Division of Safety of Dams valve testing, Hetch Hetchy valve releases will fluctuate following the schedule detailed below. All other releases are unchanged.

 

We strive to keep the user community updated on projected flows on the Tuolumne River, flows are expected to vary significantly over the coming weeks.

 

Cherry Reservoir

• Valve releases at approx. 6 cfs
• Holm Powerhouse will cycle between 50-900 cfs
• Flows will be scheduled to reduce from 140 cfs to approx. 50 cfs at 08:00 Monday April 11 through Friday April 15
• High flows will resume at 17:00 each day
• Holm Powerhouse is scheduled for a maintenance outage on April 17-18
• Generation will be cut at 08:00 on April 17, resuming at approx. 18:00 on April 18

 

Lake Eleanor

• Valve releases at approx. 11 cfs
• Full and spilling, spill rates of 50-200 cfs are expected this week

 

Hetch Hetchy Reservoir

• Valve releases from O’Shaughnessy at approx. 65 cfs
• Valve releases will increase from 65 cfs on April 18 to 1,200 cfs on April  19, then return to 65 cfs on April 20, following the schedule below

 

Time	From (CFS)	To (CFS)
4/18/22 7:00	65	100
4/18/22 11:00	100	150
4/18/22 15:00	150	200
4/18/22 19:00	200	350
4/19/22 6:00	350	700
4/19/22 10:00	1200
4/19/22 13:00		700
4/19/22 17:00	700	350
4/19/22 21:00	350	200
4/20/22 7:00	200	150
4/20/22 11:00	150	100
4/20/22 15:00	100	65

Any significant changes to the schedule will be posted on the bulletin board.