Good afternoon,

 

Notes:

-Valve releases from Hetch Hetchy Reservoir continue to decrease this week, with variable reservoir spill expected to continue in the 50-250 cfs range.

-Kirkwood Powerhouse spill will end on Saturday, June 4. All recreational releases will come from Holm Powerhouse 07:00-11:00 June 4 onward.

 

Summary:           Flows at the Cherry-Tuolumne Confluence will range from approximately 1,200-1,500 cfs during the 07:00-11:00 period.

Confluence flows during the middle of the day will be lower, ranging from 450-700 cfs.

 

Hetch Hetchy Reservoir

• Valve releases will continue to decrease this week
• June 1: 350 cfs
• June 2: 250 cfs
• June 3-5: 150-200 cfs (minimum streamflow release for June-August will be 110 cfs)
• Reservoir spill is expected to continue and will vary according to natural inflow patterns
• Spill rates between 50-250+ cfs can be expected, in addition to valve releases
• Kirkwood Powerhouse
• June 2-3
• Powerhouse spill of approximately 300 cfs 07:00-16:00
• Powerhouse spill of approximately 500 cfs 16:00-21:00
• Powerhouse spill of approximately 150 cfs 21:00-07:00 (overnight)
• June 4 onward
• Powerhouse spill to cease at 00:00
• HHWP to provide notification if Kirkwood generation increases are scheduled at a later date

 

Cherry Reservoir

• Valve releases 7 cfs
• Holm Powerhouse
• June 2-3
• Powerhouse releases of approximately 550 cfs 07:00-11:00
• Powerhouse releases will be high (~950 cfs) 18:00-07:00
• Powerhouse releases will be low (~25-50 cfs) 11:00-18:00
• June 4 onward
• Recreational powerhouse releases of approximately 950 cfs 07:00-11:00
• This pattern to persist through Labor Day
• Exceptions: “No Water Wednesdays”, the first of which  will be observed June 15
• Powerhouse releases this weekend will also occur in the evenings (18:00-23:00)
• Expect these evening generation pulses to end next week

 

Lake Eleanor

• Valve releases 20-30 cfs
• No additional spill from Lake Eleanor is anticipated

 

 

As always, stated flow rates are best estimates and are subject to change as operational conditions and constraints evolve.