Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
The plant may be operational by Thursday!
http://www.sacbee.com/news/state/california/water-and-drought/article135422349.html
An amazing feat if they do.
There was a short video there showing they are already attacking the rock pile.
Well ain’t that just the way it goes...
For two weeks they’ve been having to buy rock
to fill holes up on top of the emergency spillway, and
now, all of a sudden, they’ve got 1/2 million cubic feet
of free rock and have to figure out what to do with it.
There’s a lot to attack. But the fact that the water level dropped 23 feet after shutting down the spillway is very positive. The majority of that debris pile at the bottom of the spillway was covered with water prior to them shutting it down. Hopefully, they can drag out a good channel to flow from the dam to the river.
Once again the scale/size has been deceptive to my eyes.
Did you see the video of the bulldozer driving on the rock pile?
That’s not gravel, it is huge boulders.
I don’t know how in the heck i would attack it.
I (wild guess) think it must be over five acres of debris
and at an unknown depth.
I tried to find data showing a level gauge on the river
below the dam but had no success.
“water level dropped 23 feet after shutting down the spillway “
I haven’t figured out where that water went, but there are hints of other minor outlets.
Anyway, for those wondering what difference the power plant will make in the reservoir: flow through the plant at max is 14,000 cfs = 27,768.6 acre foot/day.
There’s a problem running the plant without elect demand. There are pumps to use the excess electricity- but they pump the water... back into the reservoir LOL! (There’s probably an obvious solution that escapes me.)
Does that mean the rock pile is 23 feet high
just from what we can see above the surface of the river?
From your link:
...crews are working to get transmission lines running from the plant reattached to the powergrid...
...the powerplant when fully operational can release about 14,000 cubic feet per second...
... the lake level rose about two feet over night to 840 feet, or 61 feet below the top...
...officials said they’ll open the spillway up again before the lake rises to above 860 feet...
...heavy equipment operators will work round the clock the next few days attacking the debris pile...
I’m pretty certain that they can make room in the generation mix to allow this plant to run. It’s not that huge in the grand scheme of things. I had read elsewhere that the plant’s total generation was capable of pumping almost 17,000 cfs, from a site not related to this incident. Although, it appears that one of the 6 generators might be out for maintenance as witnessed by an image posted earlier (the one where they were putting sandbags along the one wall) that showed the generator hole open. Maybe that’s why they didn’t quote 17,000.
The water level dropped because there was no longer 50,000 cfs pouring down the hill into the river. It likely flowed downstream, as the feather river flows into the Sacramento River farther downstream.
To clarify, I was referring to the water at the bottom of the spillway, not up in the reservoir.
That’s a great article and vid you linked in 2044.
... If only I had read it before my earlier reply I wouldn’t have thought the wuote was referring to the reservoir’s level.
There is forty one feet of snow in the central Sierras and the resorts are staying open until July 1st.
The damage to the spillway is incredible. I don’t see how the problem gets fixed before next winter, especially since the spillway will have to be opened when the snowmelt starts.
Wow, that is something.
IRONic...or maybe ironic rock...
I just don’t see until they actually repair the Main Spillway (looks a YUGE project) how they keep from filling up the river again with more debris when they have to use the spillway again.
Whoever is in charge is juggling a lot of variables.
A few more pictures have been added. The first one lends some scale to the size of the bottom of the spillway chute.
One thing in their favor is that the ravine is truly carved to mostly bedrock. I don’t think it will erode nearly as bad as it initially did. Which means that there will be a lot less debris moved.
My thought, for a temporary repair (and this is just a WAG), would be to build up the ground at the end of the good section of the chute so that the water can gently fall down at an angle rather than falling hard and beating the ground below. Use the path it’s been following and harden it as much as practical. Use that until a new spillway can be designed and built.
Like I said, a shot in the dark. I have no idea how realistic that might be.
The emergency spillway to the left is truly an extreme emergency use only tool.
Yeah.
I see the main spillway as a big problem,but not necessarily imminently threatening to life.
I see the emergency spillway as a YUGE and imminently threatening problem.
Zowie.
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