Posted on 03/07/2022 8:56:37 AM PST by Oldeconomybuyer
The Oroville Dam in northern California is the nation’s tallest dam and it creates the state’s second-largest reservoir. In February of 2017, an atmospheric river dumped a huge amount of snow then a huge amount of rain into the reservoir’s watershed.
A 30-foot wall at the top of the dam, called the weir, nearly gave way to the volumes of water and 188,000 people had to be evacuated.
“Rainfall from the atmospheric river was enhanced by about 11 to 15 percent by climate change, compared to what it would have been in pre-industrial times,” said Alexander Gershunov, a research meteorologist at the Scripps Institution of Oceanography in San Diego.
The year 2017 was the most active year on record for atmospheric rivers in California, according to Gershunov.
The ability of air to hold moisture increases with temperature. The "Earth's Future" article's conclusions were based on climate modeling projections, which show that climate change increased the rainfall at that event.
“It illustrates very well the kind of hydroclimate change that we expect to see with climate change in California," Gershunov said. "Specifically, less frequent precipitation but more intense extremes due to atmospheric rivers.”
Climate change means California’s water supply is becoming more dependent on atmospheric rivers, which are becoming more intense. So researchers hope to be better at forecasting them.
As for preventing more climate change, Gershunov said people need to enter the "next phase in the evolution of humankind" as it relates to our development and use of energy resources.
(Excerpt) Read more at kpbs.org ...
Was it EarthResearcher333?
https://www.youtube.com/watch?v=hfEmlekQo5w&t=116s
The Oroville dam is doing just fine. It is releasing water down the spillway that was repaired in 2017(?)
This release is due to all the rain and snowpack this year. Upstream from this dam. So release now to avoid problems when the snowpack melts.
https://freerepublic.com/focus/news/3524221/posts?q=1&;page=1#1
Thanks for the link. That’s it!
Looks like EarthResearcher333 is the man. Looks like he may have disappeared from FR. If so that’s a shame. FR needs more grounded, educated, and knowledgeable folks contributing to the issues and stories of the day.
When will the Oroville crisis resurface? It appeared to me in 2017 that the earthen dam itself was leaking. If they haven’t fixed that (the politicians wouldn’t even admit its existence) then it looks like the disaster is still waiting to happen.
Anyone have any updates, maybe since all of this rainfall?
You are correct he never joined into other threads after the Dam crisis. And you are also correct that besides the gates the earten structure itself was of concern to us.
They opened the spillway last Friday around noon. So far, I’ve not heard of any issues. For a billion dollars (the cost of the repair, iirc) it damn well ought to work.
https://www.mercedsunstar.com/news/california/article273130495.html
Video: See gorgeous views of Oroville and Folsom dams releasing water
By David Caraccio
Updated March 14, 2023 6:03 PM
I tell ya, if I was living below that dam, I'd be concerned enough to have moved. And my presumption is these corrupt politicians haven't done anything about the dam structure and the leaks. If so, that would make this dam a catastrophic disaster waiting to happen.
I'm just wondering if my presumption is wrong which would be a minor miracle.
They are using the new spillway now for the 2nd time
About 20,000 cfs is all
Lake about 860 ft
Well, let's hope that works.
The ongoing issue is the evidence of water coming through the earthen dam itself.
If I were living below that dam, I think I would have moved by now.
Interesting. My theory back in the day was tree root intrusion and lack of upkeep. The ground under the spillway surface was determined to be less than desirable. That certainly would allow ground critters to follow the tree roots under the spillway...
bump
I never saw a ground squirrel report. I would appreciate it if you can direct me to such.
https://damfailures.org/case-study/oroville-dam-california-2017/
“Over time, chute flows and temperature variations led to progressive deterioration of concrete and corrosion of steel reinforcing bars and anchors in the chute slab, with likely loss of slab strength and anchor capacity. There was likely also some shallow underslab erosion, damage and deterioration of the underdrain system, and some loss of underdrain system effectiveness, which contributed to increased slab uplift forces. The particularly poor foundation conditions at the initial service spillway chute failure location likely contributed to low anchor capacity and shallow underslab erosion.
The seriousness of the weak as-constructed conditions and lack of repair durability was not recognized during numerous inspections and review processes over the half-century history of the project. For example, although the poor foundation conditions at both spillways were well documented in geology reports, these conditions were not properly addressed in the original design and construction, and all subsequent reviews, including FERC five-year reviews and Potential Failure Mode Analyses (PFMAs), mischaracterized the foundation as “good quality rock.”
I don’t recall ever seeing anything about ground squirrels, but I do recall speculation about root intrusion beneath the slab from trees adjacent to the failure area. Those roots may have contributed to failure of the underslab drains and allowed that area beneath the slab to erode.
Remember the pics of the drains in the sidewall not jetting out water like they did in the rest of the spillway.
Yes I remember the sapling incursions but as the quote says the substrate condition and how the design and design administration failed to treat it was the main issue as I saw it.
The exchange about failure came after we were alluding to another issue entirely and that was the earthen dam itself, separate from the spillway. That dam was leaking and no one wanted to talk about it.
Oh no...this reporting is the cause of Global Warming with the Bull💩 that is being delivered!!
Found a reference of repair to the gates from last year:
https://water.ca.gov/News/Blog/2022/July-22/Oroville-Update-7-8-22
Seems like it is just for the hoists. Don’t see anything about the retaining bolts or the cracks.
I put the Lake level on my daily things to check on.
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