Here's a good visual explanation of what's going on:
Spillway failure
in 1st: that'll buff out!
-J0N
I have been watching this and thought the back up spill way would be able to hold up but that seems to be failing. If you are in the area you should leave.
Yay! They saved so much money by going with the lowest bidder!
There a bit of history with dams in Cali.
This really sucks, but I'm worried this won't be the last major infrastructure failure we'll see in our lifetimes.
For those that don't know, Northern California has been getting a LOT of rain this winter (and snow, Sierra snow pack is 150% of normal). There is another storm heading in next week.
Here is a more complete article on it:
http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html
Some highlights:
More than 162,000 residents in Butte, Sutter and Yuba counties were affected by Sunday night’s evacuation orders, census figures show.
State Department of Water Resources told Butte County Sheriff Kony Honea shortly after 6 p.m. that “the erosion that caused all this concern was not advancing as rapidly as they thought.”
“That’s a very good thing,” he said.
There is a plan currently in place which would hopefully plug that hole, Honea said, including using helicopters dropping bags of rock into the crevasse to prevent any further erosion.
He said two inches of water is still coming over the dam, which “is significantly down” from earlier flows.
“That has helped reduce the level of the lake,” he said. “It’s hopefully going to reduce the pressure on that alternative, emergency spillway and stabilize the situation so we can find a repair and hopefully prevent it from complete failure.”
Meanwhile, officials say they’ve mobilized swift-water rescue teams to be ready should they need to rescue people in floodwaters below the dam.
Tk8398
New Reader
2/12/17 10:43 p.m.
The part that they are concerned may fail is actually a bit west of what you can see in those pictures. You can see it in Google maps pretty easy though.
I saw this earlier.
All I could think was that California really needed this water, but damn, not that bad!
...and yet, the state government is still imposing "no washing of cars on driveways" rules to save water because we're in a drought.
Stefan wrote:
There a bit of history with dams in Cali.
This really sucks, but I'm worried this won't be the last major infrastructure failure we'll see in our lifetimes.
Considering most of the major infrastructure of our country is at least 60 years old I'd say your very much correct.
Tk8398 wrote:
The part that they are concerned may fail is actually a bit west of what you can see in those pictures. You can see it in Google maps pretty easy though.
If I understand correctly, it's basically just a part of the hillside. "If it's going to totally bust over the top, this is the least worst place for that to happen. But it's going to suck."
Am I the only one that notices the access road in the last pic would make a great rally stage?
News story this morning says they're trying to relieve 50 feet of water so they can evaluate and hopefully fix the spillway.
This photo of the reservoir at full pool is just incredible.
It's an interesting flaw. I bet up close, the concrete looks really thick and stout, but looking at it in relation to the amount of water going over the spillway- it looks tiny and insignificant. One small shift in it, and the resulting turbulence will have massive power over it. Which is what happened.
Hope all turns out well.
Ian F
MegaDork
2/13/17 7:06 a.m.
OHSCrifle wrote:
News story this morning says they're trying to relieve 50 feet of water so they can evaluate and hopefully fix the spillway.
This photo of the reservoir at full pool is just incredible.
A video I saw last night was focusing on an area to the left of the emergency spillway in the picture above. About 25% of the spillway is shown and then there is a flooded parking lot with water going over/through the embankment past the emergency spillway.
It looked like most folks were heeding the evacuation order.
When isn't California NOT on fire, out of water, too much water, or shaking itself apart?
The knee jerk reaction to 9/11 was to lower the water levels in all the dams.
Then a couple of years of dry weather and it's OMG drought!
So now they fill the reservoirs back up, because OMG. (instead of letting it out because wet winter is here)
Politicians must be running the reservoirs!
Here in Oregon the politicians want all the dams removed because the record number of salmon that returned dont have enough native fish in the count.
Who will be first to cry out when homes get washed away by floods. People have forgotten that the dams were originally built to control flooding, they have fish ladders, recreation, power & water supply was a side benefit of the dam (and should not dictate storage levels). (short memories and can't see past the next dollar they are grabbing)
Duke
MegaDork
2/13/17 8:33 a.m.
Seems stabilized at the moment. It's no longer overtopping the embankment and they're still dumping 100,000 cfs down the main spillway to relieve the emergency spillway and affect a fix.
In reply to 914Driver:
Wow, that really showed the extent of the damage more than the article.
914Driver wrote:
Short film posted on a flying forum.
^Bonus points for Schroth harnesses.
In reply to alfadriver:
From some news reports I saw, the damaged area of the main spillway had been repaired fairly recently. Something caused turbulence in the repaired area, resulting in the damage we're seeing now.
The big underlying issue is that while the whole area around here got a lot more precipitation than it did over the last few years, a lot of it was rain rather than snow even at high elevations. So instead of the snow pack gradually melting over the summer, you get huge amounts of water dumped on already waterlogged soil. This dam is probably the biggest single problem, but you see the effects everywhere - lots of mud slides in the mountains, for example.