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Oroville Dam Spillway Concrete Failure (Feather River Flooding, CA) 36

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msquared48

Structural
Aug 7, 2007
14,745

Erosion has created a 300-foot-deep hole in the concrete spillway of Oroville Dam and state officials say it will continue grow.
State engineers on Wednesday cautiously released water from Lake Oroville's damaged spillway as the reservoir level climbed amid a soaking of rain.

Situated in the western foothills of the Sierra, Lake Oroville is the second-largest manmade reservoir in California after Shasta....

Member Spartan: Stage storage flow data here for those interested:

Mike McCann, PE, SE (WA)
 
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Sometimes, topography is more essential than geology when dam sites are selected. I don't think there are credible reasons for doubting the dam. It is the spillways that are suspect.
 
So because of the flood, you are proposing removing the dam that was partly built to hold back the flood. Is that correct?

I am just wanting to know.

I personally think they should keep the dam, as I am tired of hearing about the lack of water in states where they don't manage the water resources very well.

And I don't doubt that there maybe flaws in the design or construction of the dam or spillway, but the purpose seems sound in reducing flooding.

Otherwise we could declare the land down stream as not buildable for housing, and pay to buy the land, and to move those people.
 
Little Inch said:
Interestingly this also gives section details of the spillway - looks rather simple to me.... No wonder they were worried. The section is noted later as being in the middle of the emergence spillway.

The toe directly at the bottom of the emergency spillway looks very, very thin to be projecting out that far at the first point where the water coming over the top of the emergency spillway "bounces" off towards the river below. Not surprised the emergency spillway was a point of concern for erosion once it was over-topped.
 
Let's say this facility is still here 500 years or more. If these spillway problems continue at unpredictable intervals, even if there are paved spillway chutes, will the need to protect downstream people from an unexpected 10 or 20 ft. wave finally get to be too much to deal with? Sure near full lake volume flood control will stay, even if there is complete loss of the spillway area "rock" and earth holding back that upper 20 to 30 feet of water head. Even now major improvements at spillways will be difficult to fund.
 
I am getting into this conversation late but do have some comments:

The large helicopters are Sikorsky S-64E Sky Cranes - capacity 20k lifts. Probably contracted with Siller Brothers out of Yuba City.

In about 1963, there were a number of new smaller dams just being completed. This project was for the Oroville-Wynandot Irrigation District. There was a dam recently completed and empty. I believe it was called the Ponderosa Dam. The thinking at the time was that it would take two years to fill the dam. There was a heavy storm that came through and it filled the dam in one day. I was working for Guy F. Atkinson at the time and on another project when we heard that they had almost lost the dam. Apparently two of GFACO's people went up to the dam in the evening and discovered the almost full dam. There were large tainter gates that could be opened with electric motors. But the storm had taken out the electricity and the emergency generator wouldn't start. There was a large wheel (mayby 8 feet in diameter) that one could manually turn to open the gates but very slowly. Remember there wasn't mobile phones in 1963. The two fellows worked all night in heavy rain downpours to slowly open the gates and were able to release the water down the spillway. Within the company, these guys were hero's, but I do not know what their bonuses were like that year.

There is a report (which was sent to me) called: "Report on Feasibility of Feather River Project and Sacramento-San Joaquin Delta Diversion Projects - Proposed as Features of the California Water Plan." published May, 1951. It should provide quite a bit of background. Through some conversations I have heard was that some people did not want to do the project if there was people below the new dam.



 
Sounds to me that these structures were not designed to the maximum PMF they could see. Probably need reanalysis and major spillway modifications...

Mike McCann, PE, SE (WA)


 
The captions on one of the photos indicates that Yuba City was flooded on one occasion due to its levees failing after an 100 kgal/s discharge from Oroville. The entire project as a WHOLE is the mechanism for dealing with floods, which includes Oroville itself, the levee system, and other flood control gates further downstream. As population increases and more people wind up in the flood plains, the potential for damage increases.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Anyone with a 3D Printer, you too can have your very own model of the Oroville Dam, perfect for setting up a miniature hydrology lab in your bathtub:


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
It's missing some of the newly developed 'features'. :)
 
I wonder if it is possible to print part of the spillway with water soluble media. A real working model. grin

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
For an overall picture of the current status of California reservoirs, including Oroville, here's an interesting graphic:

URL]


For the full article, which includes some additional graphics showing river levels throughout the greater Sacramento Valley, go to:


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Lake Berryessa (at the Napa Valley area) is also refilled 100% + from the used-to-be-permanent drought, and is pouring back out its spillway (the Glory Hole behind the dam.)
 
Lake Berryessa; Last time I drove around it it was going over the terrifying lip
of the overflow and the water was coming out the pipe a hundred yards away at the
bottom of the dam like a Devil's fire-hose. The road that goes around the
southern edge of the lake had a handful of creeks running across it that were a
foot deep. It provided a lot of pucker-factor in a Renault 10. I bet those creeks
are really ripping now.

As for the San Luis Reservoir... It has provided me with lots of interesting
learning experiences. As a kid in high school my dad dropped me off on a hundred
foot diameter island two hundred yards from shore. This was so I could sit in a
duck blind in the center of it with my 12 gauge in hopes of bagging some ducks.
To my horror I soon realized just how fast they could raise the level with their
pumped storage. I could see my fifty foot shore line shrinking by the minute.
I was starting to consider the swim to shore when my dad came back. My island was
about 10 feet in diameter when he returned. He thought my 2 hour torture was hilarious.

Recently I stopped at the visitors center with my son at 3am on the way back from Fresno
so we could relieve ourselves. Of course it was closed so we only made it half way to the
center barred by their gate. In desperation we jumped out into the star dazzling pitch dark
in a steady 40 mph wind.

We both learned that peeing in that much wind was a very bad idea, best described as
omni-peeing.

Keith Cress
kcress -
 
Despite the reservoirs being at, or over, capacity, California's aquifers were severely depleted over the past 7 years, and those may take as many years, if not more, to replenish.

Oddly, San Francisco's beloved Hetch Hetchy Dam is not part of the state's water project, so statistics aren't listed there for it, but are here:
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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