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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"Hello river folks -
After saying that everything was calming down, the storm that came in last night really hit several of the watersheds hard - over 2 inches of rain on wet soils and melting snow.
HHWP has increased the release at Cherry Dam from 20 cfs to 3000 cfs, and tomorrow at noon HH release will rise from 1700 to 3400 cfs. Middle and South Fork are climbing now, and will add at least another 500 by later in the day.
Lumsden flow will rise from the current 5500 cfs and rising to 9000 cfs by 11 am today. Tomorrow around 6 pm it will rise to 10,500 or so.
Sorry for the quick reversal, and OUTFITTERS - please make sure any trips planned for today are aware of the change that is coming in two hours from now."
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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"Hello river users -
River flows and emergency releases have backed down now that fair weather has returned. The weather will then cycle quickly to very hot with the peak temperature occurring on Monday the 4th.
Lumsden flow has dropped to 7500 cfs, but the release from HH increased 1500 cfs at noon today, so Lumsden flow tomorrow (Friday) will see about 8000 cfs. I expect that Saturday will drop to 7000 cfs. Sunday will be between 5500 and 6000 cfs, and Monday the 4th should be between 4500 and 5500 cfs.
The effect of the heat is hard to predict right now, but I do not expect Lumsden flow to go above 6000 cfs between the 4th and the end of next week. Because the reservoirs are full except for Hetch Hetchy (and it is mostly full), we have very little ability to control flows. I will be in contact if reservoir regulation (or spill from full reservoirs) is likely to raise flows above 6000 cfs.
Please boat safely, and wear all protective equipment. Have a great Independence Day holiday."
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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"Hello river folks -
The heat is melting the snow fast at the top of the basin, and with all three reservoirs basically full, what is coming in has to come on down the river. Inflows to Hetch Hetchy are rising, and I have little room to store that water. As a result, the discharge at the dam was increased by 2500 cfs this morning, and another 500 cfs was added this afternoon.
Lumsden flow is at 6300 cfs now, a little lower than the 7000 cfs I predicted on Thursday. However, instead of going down through the weekend, it is going to rise to about 8800 cfs about 4:30 pm today and go on up to 9200 at 7 pm or so. It will stay in that range through Sunday and probably Monday.
I expect it will start coming down again after Tuesday of next week, but the amount of snow in the highest elevation portions of the basin was huge this year, so we could stay above 7000 cfs for most of the week.
I will send a new bulletin on Tuesday or whenever conditions change again."
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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"Hello river folks -
The hot weather has kept snow melting at maximum rates, but the high elevations are finally starting to melt out, and clouds have also slowed things down. As a result, HHWP will be making small cutbacks in release rates to hold reservoirs water levels up.
Lumsden flow has dropped from 10,500 cfs a few days ago to 9,700 cfs today. It will drop to about 9000 cfs tomorrow (Thursday) afternoon due to minor cutbacks that will be done at Cherry and Hetch Hetchy. The moisture and thunderclouds from Tropical Storm Arlene should clear out by tomorrow noon and snowmelt will pick up a bit, but the triple-digit temperatures in the Valley will end, and temps are supposed to drop back to the normal 90's. Lumsden flow should start to edge down each day and be between 7000 and 8000 cfs over the weekend. By Tuesday the 12th we should go below 7000 cfs and not come back up again.
If conditions are diverging significantly from this forecast, I will send out an update Friday morning."
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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"Hello river recreationists -
The cooler weather and declining snowpack have caused flow at Lumsden to begin falling toward the summertime normals, but a few more weeks of higher flows on the Hetch Hetchy side can be expected.
Cherry Creek (between Holm PH and the confluence) can be expected to be below 2,000 cfs from this time forward. Holm PH is running about 975 cfs round the clock for the next week or two. Cherry release will stay below 300 cfs, and Eleanor releases will drop to 20 cfs or so sometime tomorrow, but will then come back up to less than 400 Thursday or Friday. Consult the gage below Holm for a real-time reading of that side:
http://waterdata.usgs.gov/ca/nwis/uv/?site_no=11278400 [waterdata.usgs.gov]
While the "Cherry Creek Run" may start in Cherry Crk, most of it is in the Tuolumne mainstem from the confluence to Lumsden. I am told that if flow is much over 2,000 cfs at Lumsden, the run is not generally attempted. We are dropping the release at Hetch Hetchy from this morning's 5,000 cfs to about 2200 cfs on Wednesday. About 500 cfs is being released at Intake, so the Cherry Creek run will continue to be unavailable through the week. I would expect flows on the Hetchy side to stay above 1000 during the week of July 18 as well. The Creek Run may become available the last week of July, but it is too early to make promises.
Lumsden flows are currently about 7500 cfs, but by Tuesday morning (7/12) they will be about 5700 cfs. On Wednesday morning they will be about 4800 cfs. On Thursday morning they will be about 4000 cfs. They should remain between 3000 and 4500 cfs through Sunday, and I will provide another update on Thursday."
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cgoold
Member
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Posted: Jul 14, 2011 Post Subject: updates on cherry creek above holm powerhouse?
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| | Several groups are interested in any updated forecasts for flows in the section of cherry creek upstream of Holm Powerhouse for the coming days, if such a forecast is available. Are there still plans to adjust the release from Eleanor Lake? Is it expected that the Cherry Lake release is likely to remain stable?
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chris
Site Admin
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| Hetch Hetchy Water and Power reports as follows:
"The cool weather continues to slowly decrease runoff across the watershed. We expect flows to continue to slow with a slight bump up with the return to normal temperatures next week , but it will only be slight. Right now below HH there is ~2700, ~ 250 below Cherry, ~30 below Eleanor. Flows below those reservoirs will remain near those values for the next 5 days. This results in the Cherry Creek run still being too high and the estimate of the last week of July as the earliest point of flows dipping below 2100 on that stretch of the river still stands. For those watching for that run closely, spill at Hetch Hetchy needs to be below 500 cfs for it to open up. So it is getting closer.
Flows at Lumsden will be remaining pretty stable over the next week and remain in the 3000 to 4500 cfs range. We do not expect flows to surpass the 5000 cfs mark again this runoff season.
Enjoy the cool weather before the heat returns."
Carlton - I believe that answers your question about Cherry above Holm. If not, let me know.
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cgoold
Member
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| | Thank you, that is exactly the information that we needed.
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pearen
Member
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| | Any update on Cherry Creek flows for this week? Seems like it is getting closer...
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Flow Forecaster
Member
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| Here is the latest "short-term update" for the Cherry Creek run:
Wednesday Aug 3: There will be ~1400-1500 on the mainstem of the T above Cherry Crk, and Cherry Crk will have ~175 up till 9 am and ~500 after 9 am, So I come up with about 1575 to 1675 at the confluence of the T before 9 am and 1900 to 2000 after 9 am.
Thursday Aug 3: For the confluence: Decreasing spill/release from HH should result in 1300 to 1500 prior to 9, 1400 to 1600 till noon, and 1900 to 2100 after noon.
Friday Aug 3: In the morning there will be 1100 to 1400 prior to noon and 1500 to 1900 in the afternoon.
The boating flows from Holm PH have not begun yet, but HPH is schuduled to contribute some flow during the "boating release period" 7-11.
Thunderstorms last weekend changed the forecast and operations. However, there is no forecast for additional t-showers this week. If that remains the case through the weekend flows will remain below 2000 and likely in the 1000 to 1500 range, watch for the weekly river update on Thursday.
Remember to check the real time flow gages.
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chris
Site Admin
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| I've been out of town, not able to post. THANK YOU Flow Forecaster for your post while I was away. Here's the most recent Hetch Hetchy communication, from Aug 4:
"Hello River Folks:
We are coming into the 2nd week in August and snowmelt runoff is just about over! Unbelievable year - wet fall, wet winter, cool spring, wet June, cool summer, and thunderstorms, all of that and big flows on the Tuolumne. The tail end of runoff on the Hetch Hetchy side will impact the flows a little bit, but there will at least ~1100 at Lumsden during the usual boating hours, which hit Lumsden around 9 am. In general there should be greater than 1200 cfs at Lumsden during the daytime hours, below are the ranges that encompass flows from ~0900 to ~1700 hrs at Lumsden with an estimate for South and Middle Fork. Evening and nighttime flows at Lumsden should remain 1000 cfs or greater.
Friday: 1200 to 1900 cfs (highest flows in the afternoon)
Saturday: 1200 to 1600 cfs (highest flows during normal rafting hours)
Sunday: 1200 to 1600 cfs (highest flows during normal rafting hours)
Monday : 1350 to 1500 cfs
By Tuesday do not count on boating flows around the clock at Lumsden. ~1100 cfs will be at Lumsden during the boating hours.
Tuesday-Thursday ~1100 cfs, arriving around 9am
The Cherry Creek Run is now "in", but be aware HPH is not doing it's typical summer releases yet and you should consider the Early Intake bridge as a put in. I will give the details below, so you know what to expect for that run:
Friday: 900 to 1100 cfs below KPH all day: 7 to 12, there will be ~250 cfs on Cherry Creek, 12 to 7 there will be closer to 700 cfs on Cherry Creek
Saturday: 900 to 1100 cfs below KPH all day: 7 to 11, there will be ~450 to 500 cfs on Cherry Creek, 11 am on there will be ~150 cfs
Sunday: 900 to 1100 cfs below KPH all day: 7 to 11, there will be ~450 to 500 cfs on Cherry Creek, 11 am on there will be ~200 cfs
Monday: 900 to 1000 cfs below KPH all day: 7 to 11, there will be ~450 to 500 cfs on Cherry Creek
Tuesday: 400 to 500 cfs below KPH all day, 7 to 11 there will be ~750-850 cfs on Cherry Creek
Wed -Thursday: Likely the usual release from HPH and ~125-150 cfs below KPH.
As we move into the typical rafting schedule do be aware that August 17th and 31st are scheduled as non-boating days and are reserved for maintenance. View the schedule here: http://www.dreamflows.com/Pages/TuolumneSchedule.php
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chris
Site Admin
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| In response to my question about possible boatable releases in September, Hetch Hetchy Water and Power responded as follows:
"Unfortunately, we can only do rafting from Holm releases, and we have serious switchyard maintenance/breaker replacement going on starting right after Labor Day. So there will not be generation or water during September."
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Cornbread
Member
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| Posted: Aug 23, 2011Post Subject: September Calender
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| Hi Chris,
Thanks for the continuous updates regarding flows. I noticed the calender for Sept is actually from 2010 so I was wondering if the creek would be running Labor Day Sept 5th? Hoping to make it there at least one weekend this summer....
Thanks!
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chris
Site Admin
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| | Thanks for letting me know. It was a typo, now fixed.
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chris
Site Admin
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| As the result of a special request for information, Hetch Hetchy Water and Power reports as follows:
"We will be running Holm PH later this month and in November. We are also going to be releasing from Eleanor (likely in the first week of November) -- maintenance work at the dam. At this point I am not completely sure of what it will look like -- but higher flows during the daytime hours (300-500 when HPH is running and could get closer to 1000 during the day when we do Eleanor releases). I am guessing we will have some additional water out of HPH next week."
[The above request for information came from a fisherman. Even though Dreamflows was conceived primarily as a whitewater paddling website, nearly 15% of visitors are non-paddlers. At least, that's based on the folks who have Dreamflows accounts and checked the "Primary river interest" box. Interesting, no?]
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