Planning a trip from my Sacramento-area home to Klamath Falls to check out real estate for a possible/probable move.
I spent three days evacuated out of my home last February due to the spillway failures at Oroville dam. Don't want to ever do that again. (I know, here goes Anne again, blah, blah, blah
).
Of course, since then, what was left of the lower part of the main spillway after it failed (not much) has been demolished, the canyon that the water had carved has been filled in, and the spillway has been rebuilt/replaced. The upper part of the main spillway is scheduled for the same treatment after the rainy season here ends (about May).
However (I am shocked, I tell you,
shocked!) they are now finding "hairline cracks" in the newly-poured concrete of the repaired/replaced portion of the main spillway. DWR (California Department of Water Resources) assures everyone that this is a normal consequence of concrete curing.
Whew! No worries there, then.
It was (and is) DWR that is responsible for the inspection and maintenance of the main spillway, so that the spillway would remain safe, and in working order. You know - the spillway that failed.
It was DWR that said that water releases had been increased on the damaged main spillway, so that the "emergency" spillway would not need to be used. You know, the one that was not actually a spillway at all, just your average California dirt hillside with trees and brush and grass, with a concrete lip at the top.
It was DWR that said, once water began to flow over the lip that the spill (down rapidly-eroding dirt hillside) was "under control, no problem". (Watch what happens when you aim your garden hose at the dirt in your backyard - the water will dig a hole with the water coming out of your hose at about 1 cubic foot per minute. The water coming over the concrete lip was hitting the dirt at a reported 12,000 cubic feet per
second.)
That is, until one of the few people at the dam who were apparently paying attention noticed that a major crevasse was being excavated in the hillside by the water, the crevasse eroding closer and closer to the concrete lip. Had the concrete lip been undercut by the erosion, to quote Butte County Sheriff Kory Honea (the man who called for the evacuation, after,
by chance, accidentally over-hearing a conversation by DWR engineers): "It was not whether people would die, but how many would die.”
Then, suddenly, it was time for 200,000 people to hit the road. All at once. I was one of them. They gave us an hour to git outta town.
So! No worries about the hairline cracks on the newly-rebuilt portion of the spillway, though. Whew! DWR has it under control! Yeah!
On the other hand, haven't read nothin' coming from DWR about the effects of cavitation on small cracks.
https://www.usbr.gov/ssle/damsafety/risk/BestPractices/Chapters/VI-3-20150610.pdfBut I'm not an engineer, so what do I know?
Anne
Posted: Mon Jan 08, 2018 8:51 am
I'm currently in the Keys, visiting some friends I met my very first winter RVing, in El Centro, CA. They live/work in Marathon now. Just hopping around FL, visiting friends. Got to meet a 2nd cousin in Leesburg. Planning to leave the Keys tomorrow afternoon and spend a couple of nights at a casino, before heading over to Palm Beach to visit a friend I made at Amazon one year. From there, I plan to join Vicki and Dave in Avon Park. Plans are in the works to go to the Tampa RV Show with a friend or more. Lots of friends to see in FL, then thinking of heading over to MS to visit a friend and LA to visit my nephew and his wife. I have to live on the cheap, so lots of boondocking is likely.