Skip to comments.Emergency: California’s Oroville Dam Spillway Near Failure, Evacuations Ordered
Posted on 02/12/2017 4:26:47 PM PST by janetjanet998Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
Here's a puzzle for y'all (and you too Freeper "abb"- welcome). A few days ago a swarm of workers (bees, yellow jackets :-) ) were shuttling buckets of some type of material to a location adjacent to the upper main spillway concrete wall. What is potentially coincidental (and unconfirmed) was radio traffic of a crack in the upper main spillway dam road. This (unconfirmed) radio traffic included back & forth talk of water leaking in this "crack". All of this coincides with the mystery "bucket" activity.
If there were to be any type of seepage or leaking from a crack in the dam roadway, it would have to been equal to or lower than the water level at that time. The surface of the spillway is at 813.6ft MSL. The walls of the spillway are stated to be from 20-24ft high. Rough calc: Using 22ft for a wall height, this puts the wall near 835.6ft at the location the workers are shuttling to and from. You can see one of the workers bent over looking down to the location of interest. (where everyone is going to and from). Since they are carrying empty buckets on the way back, and you can see others carrying non-empty buckets (via weighted buckets in their posture) going to this location, this indicates material is being deposited.
The water level was above 850ft at the time of this work. If the workers w/ hats are 6ft this puts the location at 829.6ft. Thus the water side of the spillway entrance is at least 20.4ft higher than this location of interest.
For the sake of theoretical discussion, if there were some type of crack & leak discovered, it most likely would have been on this side of the dam road. Why? Because the dam road curves downward in elevation towards the Emergency Spillway and is within the 20.4 ft "head" of water pressure. Could it be possible that water is finding its way into the berm to the left of the workers? The grout curtain is deep at the footing of the spillway (at least 50ft deep). But is water finding its way through cracks?
Has there been any official statement on why such a concentrated focus of shuttling of big buckets of material to this location? Also note the minor rockfall from the embankment near this location (could be just another coincidence).
The other mystery is what material leaves this very "mud looking brown color" in the buckets?
I just find it interesting.
Thanks for the pings.
The bucket brigade was a few days ago, but I do wonder what they were up to. I don’t imagine they were filling potholes in the gravel along the wall, but who knows.
I have never been able to figure out what all those guys with the buckets of rocks were up to.
Info at the time said they were volunteers from some Cal Conservation Group.
I figured they wanted to ‘help’ so they were given some busy work...
I thought maybe just making a safe walking surface for observers/inspectors...
I really have no idea.
That bucket brigade fascinated me also. Was there some of the backfill along the wall that was eroding? Did they fear a washout that could have taken out more of the spillway?
>>Bucket mystery discussion:
Given the volume of the buckets times the number of them in just these two photos, the ground would be bulging from the sum of the material. This indicates there is a “hole” that is being filled.
Now what type of “brown material” would you use to fill a “hole” - especially in a water sensitive situation? Is the hole a sinkhole? If so, this indicates something eroding or washing material away. I would/could believe that a flow could be going down towards the lower sidewall of the spillway. The hydraulic flow (or underflow) near/at the slab & sidewalls could be facilitating an evacuation of this “flow”.
from what I just read of that local article and other sources..
1) water is being released from the smaller resevoirs to meet the fish requirements
2) they have enough storage to do this for 7 days (well 4-5 now)
3_ that article said if they can’t get the power plant back online after 7 days they will have to use the main spillway again
4) I’m not sure how much debris they have to remove to prevent backup but 1.5 million cubic yards is estimated washing in and they removed 60,000 so far
5) if they use the main spillway it will dump more debris back into the channel
translation: they have more 5 days to remove enough debris or maybe start over
The bucket brigade was making a path on the cobbles that backfill the walls on the upper spillway chute. There were/are roving teams monitoring for any upstream failure of the chute and walking on cobbles really suck, particularly at night. I know I was part of that monitoring team.
The CCC team really earned my respect - worst working conditions, very manual labor yet they were positive and always address people as ‘sir’ or ‘ma’am’
Thank you much for the information, and for helping out.
I’m all the way over in Tennessee, but I find this situation fascinating.
Did you pick up any information on how the underslab drainage system worked? Or how they connected to the drain outlets in the walls?
Aerial view of main spillway damage taken 2/27/17
(from an interested but unaffected observer in Georgia)
Thanks for your effort out there.
It all seems like it depends on the weather at this point...
The lake level is at 844 1/2 and rising about 2 feet per day.
They have said they will let it fill to 860 feet before
they re-open the gates on the main spillway.
They are doing what they can to control the inflow, but
another storm or warm weather snow-melt and all bets are off.
So I guess those guys moving rock out of the river
are working 24/7 for as long as the weather holds out.
Debris dumped into pond near Diversion Dam
Hi abb, I would alter your sketch to angle the horizontal drain pipes upslope. Although the original design stated "horizontal pipe drains" (1)(2) , they were "redesigned" or modified during actual construction to be angled upslope - denoted as a "herringbone pattern" (3). The yellow highlighted archives describe the angled slope (downward) into a "Longitudinal collector system". The modifications of angling in addition to resizing the drain pipe to 6 inches allowed for "increase in flow capacity" and "its self-cleaning ability". Makes sense.
The drainage system depended on a "foundation" beneath the concrete slabs with gravel "enveloping the drain pipe" to facilitate the collection of water. Line item (4) infers that the pipe was partially encased into the concrete floor of the chute, but surrounded (enveloped) by gravel. Early photographs of the Main Spillway bed show a compacted layer of aggregate and/or gravel at the top of the Main Spillway outlet gate area. Construction archives do not define the extent or thickness of this layer & if this layer was continuous underneath the full length Main Spillway. The only term used is "foundation". (Insiders with further info - invited here to chime in ).
Why do I get the feeling they really don't want you to know?
I’m not ready to put on my tin foil hat! (yet)
I think it was some volunteers just trying to help out.
Super Tractors - a dual D9 tractor became a workhorse for clearing the Oroville Dam Spillway. Clip below from Peterson Caterpillar History. Images reveal "side saddle" operator controls for the earlier prototypes. These tandem linked tractors were used with dual ripper shanks to rip down to rock. These tractors also were used to "push assist" the earth mover "DW20 pull-scrapers". This is an interesting legacy of history tied to Oroville and the progression of Caterpillar innovation.
= = excerpt: Building the Oroville Dam
Oroville Dam one of the greatest water projects in California history, was completed in May 1968. It is the keystone of Californias $2.2 billion State Water Project, built in the 60s and 70s to provide water for arid Southern California. Oroville began in 1957 with the relocation of U.S. Hwy 40 and the Western Pacific RR which both ran right through the future reservoirs lakebed.
Oroville Dam was where Peterson cut its teeth on in combining traditional product support with innovative custom fabrication. Five years earlier (1957) Peterson had been awarded the northern territory belonging to Sierra Tractor because Caterpillar felt Peterson was better equipped to handle the large-scale water projects than the local ag-dominant dealer. Trinity Dam was followed by Whiskeytown Dam (both near Redding) and in 1962, the mammoth Oroville Dam construction officially began.
The job veered away from conventional construction methods when the bid winner Oman Construction out of Nashville decided to transport fill materials using a railroad system rather than trucks and scrapers. We were gambling on some of our contractors getting Oroville Dam, recalls Howard Peterson. We went to the bid opening in Sacramento and an unheard-of, out-of-state contractor, was low bidder. We were sick. Howard and Buster immediately flew back to Nashville to meet Bill Oman. We had a very warm reception. He took us into his home and practically treated us like sons. Two days later, Howard left Tennessee with a large machine order and the beginnings of a promising work relationship with Orovilles lead contractor.
Peterson fine-tuned its large fleet product support system, begun at Trinity, by providing a fully stocked, onsite parts trailer that was serviced daily from the new Chico store. Resident mechanics and round-the-clock service were also part of the package, along with a 60-piece order of new machines and rental equipment, which included: ten D9s, some D8s and compactors, 20 bottom-dump wagons powered by 660 tractors, four 660 scrapers, some 988 wheel loaders, a couple No. 16 motor graders and six rental DW20 (pull-scrapers). Everything used on that job was CAT, if CAT made it at the time.
The scope and difficulty of the project really put Peterson to the test in terms of whether to supply the traditional means or really step up and be progressive and offer new solutions to head-scratching problems. According to Western Construction magazines October 1966 issue, Busters Quad D9s were the star of the show on the $20 million spillway.
Excavation of some 4 million cubic yards of solid rock made it one of the biggest ripping jobs in the West at the time. One million yards of that material had to be ripped using various methods, including Petersons new Quad D9 arrangement, outfitted with two 10-ft shanks, each with 4-ft extensions. The rock was so hard that when points and shanks wore out, they simply replaced rather than rebuilt them. Also new on the dam portion of the project was CATs new hydraulic 660 tractors pulling Busters 97-ton Athey rock wagons [patent # 3185528] designed especially with hydraulic actuating hopper doors for Oroville.
Along with new equipment innovations, Peterson made heavy use of its parts drop system, begun at Trinity Dam to expedite the heavy parts demands. Oroville was the main reason for bringing the nightly shuttle truck up north, according to retired shuttle truck driver, Fred Knowles who clocked over 3 million miles on the road for Peterson.
Today, Oroville still stands as the tallest earth-fill dam in the United States and among the top 20 in the world. The job was considered the most highly automated of its kind in the 1960s, involving an astounding volume and variety of equipment, much of it specially designed. Aside from the traditional CAT equipment used on the job, Oman employed several of Buster's innovations including the Quad D9s, the Athey bottom-dumps and the tandem 631 compactor.
BIG Magazine stated that, if the material for the dam was moved by wheelbarrows, placed end-to-end, they would extend to the moon and back. More than 1.5 million RR cars made the trip from the tailing dump to the dam enough to circle the globe at the equator, several times. The RR handled more than 300 million gross tons, more than several of the nations largest commercial railroads combined. In other words, Oroville was, and still is, considered one of the construction marvels of the heavy construction industry.
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