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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "River Folks - The cooler weather has finally begun to decrease runoff, but flows will remain high through the weekend. The NWS is debating the amount of cooling through the weekend and into next week, so the exact decrease in flow is problematic.
We will be reducing the release from Hetch Hetchy by about 1000 cfs today, and there will be another 500 cfs combined decrease from Cherry and Eleanor. All PH operations will continue as they have been - 1000 cfs release from Holm PH and 700 cfs release from Kirkwood PH.
The reductions will cause flows at Merals Pool launch point to decrease from the current Dreamflows estimate of 14,000 cfs to about 12,500 cfs.
We expect to be able to control releases by next Friday and through the weekend so that flows at Meral's Pool will be in the 8,000 to 10,000 cfs range. This prediction is following the NWS forecast of cooling through the week. If the lone NWS forecast model saying more heat proves right, flows may exceed this level. I will communicate with you all again on Monday and refine the flow estimate."
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "Hello River Folks - The weekend's cool weather has decreased inflow to Project reservoirs, and the National Weather Service forecast calls for low 70's at the critical 8,000 ft elevation throughout the week. The River Forecast Center holds inflows fairly steady at between 7,000 and 8,000 cfs into Hetch Hetchy for the next week. Spills and drafts from all three Project reservoirs are easing, and we now have 25,000 AF of storage room in Hetch Hetchy in case of thunderstorms or unexpected snowmelt inflow.
As a result, we reduced the release at O'Shaugnessy to 5,000 cfs this morning (Monday), and minor reductions in releases will also be made at Cherry Reservoir and Lake Eleanor. The 2,500 - 3,000 cfs reduction in Project releases, as well as decreased runoff in the Middle and South Forks, should bring the flows at Lumsden Bridge down to between 9,000 and 10,000 cfs by about 5 pm today. We expect to maintain this approximate release rate through Monday, June 19, although further minor decreases in releases are possible. If any significant changes become necessary, you will be notified immediately.
best wishes for safe boating"
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "River Folks - Due to the very cool weather, reduced inflow, and our log boom configuration, we have reduced the release at Hetch Hetchy from about 5,000 cfs to 2,500 cfs. This will reduce the flow at Lumsden bridge to about 7,500 cfs.
Temperatures are forecast to be up 5 degrees tomorrow (Thursday), and up another 5 degrees on Friday, so by the end of the weekend the inflow should increase and we will probably have to go back to the 5,000 cfs on Monday or so.
have a good weekend"
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "Good Morning......
Hetch Hetchy will be increasing releases from O'Shaughessy this morning to 2800-3000 cfs.
Cherry will be increased to 400 cfs.
Additional increases may be made over the course of the week-end based on inflows."
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "Good Morning......
Hetch Hetchy will be increasing releases from O'Shaughessy at 1:00 today by 2500-3000 cfs (release at dam will be 6200 cfs to 7000 cfs)
Cherry release is being increased this morming by 100 cfs (releases at dam will be 650 to 700 cfs)
No change at Eleanor
Additional increases may be made over the course of the week based on inflows."
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chris
Site Admin
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| | The San Francisco Public Utilities Commission reports as follows: "We do not anticipate any increases in releases below O'Shaughessy for the rest of the summer. We will begin tapering off releases below HH facitilites some time next week."
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports as follows: "Friday morning we are reducing 250 cfs at O'Shaughnessy.......for a total of 5250 cfs.
Discharge to remain the same at Cherry......750 cfs; and Eleanor......600 cfs.
No further changes are anticipated for Saturday or Sunday."
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports as follows: "While the recovery effort continues below Early Intake, flows from Hetch Hetchy Reservoir will be reduced today. Following the effort, releases and spill at Early Intake will be increased. Based on the information I have before me, we will begin spilling about 750 cfs at KPH and doubling the releases below HH (about 2500-3000 cfs) after 1200 today. We will update you as more information becomes available".
Then later they continued with:
1) We will be increasing the release below Cherry to ~360 cfs (doubling from 180 cfs) this morning.
2) At noon, we still plan on increasing the gen at KPH (spilling about 750 cfs at KPH into the Tuol and doubling the releases below HH (about 2500-3000 cfs)"
Then later still:
"We have lost a unit at KPH and are only getting 720 cfs through the unit. Therefore, we need
to release the balance (500 cfs that would have flowed through KPH) below O'SH. Therefore,
we will have about 60 cfs of spill at EI and around 3000-3200 cfs of release at O'SH".
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chris
Site Admin
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| | The San Francisco Public Utilities Commission reports again as follows: "We have lost KPH2 for the remainder of the spring. Because we will have to have reduced flows through Canyon Tunnel, we will make the balance out of the release below O'SH. After 1200 today, we will be increasing the release below O'sh by about 500-600 cfs. There may be a small increase below Cherry of 100-200 cfs. I will update you after we have the final reservoir readings."
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chris
Site Admin
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| The San Francisco Public Utilities Commission reports again as follows: "Inflow to HH Res. is dropping after the heat and with this slight cooling, and the release was decreased today to about 2200 cfs, which will result in about 4600 cfs at Lumsden through Sunday the 9th. As inflow is predicted to continue to drop, the release will drop on the 10th to about 1500 cfs.
Cherry and Eleanor releases will also decrease by about 300 cfs around July 6 and 7, and during the week of the 10th, Lumsden flow will be about 3500 cfs during the usual summer boating hours (8 am until noon) until Friday, July 14. On about the 10th, Holm PH will start cycling to conserve water, so remember that flows at Lumsden will drop off by about 950 cfs after between noon and 3 pm of each day. On the 14th the HH release will have to drop another 250-750 cfs, and Lumsden flows during the boating hours should be in the 2700 - 3200 cfs range on Sunday, July 16, as other tributaries continue to decline."
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chris
Site Admin
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| Hetch Hetchy Water & Power reports again as follows: "River folks - Inflow is decreasing rapidly, and spill could be over by about the end of next week (July 21). Our boating calendar does include Sunday boating on July 23 and 30.
Cherry and Eleanor are at minimum streamflow releases, and Holm PH is releasing ~950 between 6 am and 10 pm and ~250 cfs between 10 pm and 6 am. We plan to reduce the duration of the high flow through Holm PH to 8-12 hrs next week, but morning flows will be maintained per our boating calendar.
The release at Hetch Hetchy is 1100 cfs but may decrease to ~550 cfs on Saturday. The continuous release at Early Intake is about ~200 cfs. We plan to reduce the duration of the release at Early Intake to 8-12 hrs in about 6 days, and stop it entirely in about 12 days."
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chris
Site Admin
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| Hetch Hetchy Water & Power reports again as follows: "River Folks - Spill at O'Shaughnessy is fading fast, and that spill down the Tuolomne reach to Cherry Confluence has been providing a large part of the Lumsden water. As spill stops, Holm PH will increase to typical summer operation (~975 cfs from 7 to 11 am, plus ramp up and down) and provide the bulk of the recreational release, targeted to provide flow at Lumsden between 8 and noon. Sunday the 30th will have a release, as per our agreement.
The release at Cherry is 16 cfs.
The release at Eleanor is 22 cfs.
The release from Holm PH is ~675 cfs Thursday - Saturday, 7 to 11 am
The release from Holm PH is ~875 - 975 cfs, 7 to 11 am, Sunday and on
The release at Hetch Hetchy is ~125 cfs and about 150 cfs spill.
The release at Early Intake is ~220 cfs.
We will reduce the release at Early Intake to zero Monday or Tuesday, and at that will leave about 140 cfs in the reach from Early to Cherry confluence.
Good luck escaping the heat ... and be safe."
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chris
Site Admin
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| On Thurs, Aug 3, Hetch Hetchy Water & Power reported again as follows: "River Folks - Spill at Hetchy stopped last week, and inflow has dropped significantly. As a result we have cut back all discretionary releases except for those that follow the Boating Release Schedule. We have Sunday releases scheduled for August 13 and 27, plus the usual 4+ hours of releases on Monday through Saturday.
The release at Cherry is 16 cfs.
The release at Eleanor is 19 cfs.
The release from Holm PH is ~960 cfs for 4 hours (between 7 am and 11 am) and variable between 50 cfs and 300 cfs in other hours.
The release at Hetch Hetchy is 126 cfs.
I will not be sending additional email unless changes are anticipated."
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