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Re: Oroville Dam

Unread postPosted: Wed 19 Apr 2017, 08:00:53
by vtsnowedin
GASMON wrote:Agree - but the consequences of failure / getting it wrong are immense.


Well there certainly will be a tendancy to overbuild this time but it is hard to overbuild when the inspector is "Mother Nature". :)
"Hey should those rock anchors be one inch diameter and twelve feet long.?" "Nah just to be sure let's make them two inch and thirty feet long."$$$ :)

Re: Oroville Dam

Unread postPosted: Wed 19 Apr 2017, 11:26:12
by hvacman
vtsnowedin wrote:
GASMON wrote:Hhvacman the LA times report seems very thorough and professional.

It seems an immense task to repair. The USA once rose to these events with alacrity and engineering prowess. I hope "the lowest bidders" know what they are up against.


While the quantities of material required are huge there is nothing especially difficult about this project though some will pump it up to get an award or two. This is much less difficult then building inside an operating airport or building a highway or tunnel in an inner city while maintaining traffic unimpeded. Why there isn't even a caisson to sink a foundation in a hundred feet of water and two hundred feet of muck.

Kiewit was my personal pick when I saw the bidders list. They have a very good track record with these big projects. They already are mobilizing, with the goal to have a temporary concrete batch plant suitable for the concrete volume in-place by the time the last spill of the year is done.

Yes, this is not like the Big Dig, the new SF Bay Bridge, or other mega-projects done in tight quarters. The daily logistics are simple, but the seasonal and chronological logistics are a nightmare. Several things complicate the proposed construction:

1. The time frame. They absolutely HAVE to have the new upper spillway done by Nov 1. The old one will be demo'ed. Kiewit can't start now - the DWR is currently spilling 35,000 CFS trying to drain the the lake some more. Nature isn't cooperating, as we are having a very wet spring, along with the heavy snow-melt. They started spilling 5 days ago and the lake level has only dropped 4 feet. They have to get it down another 26 feet. They will have to spill for at least another 10-15 days and will probably have to do one more spill in late May to get the lake back down to 835 feet where the Army Corps of Engineers are telling them they have to set their max level until the new spillway is done. Only then can Kiewit begin demo of the existing upper spillway and start infilling the existing plunge pool rock-canyon with roller-compacted concrete.

2. The unknown geological situation below the existing spillway. As they demo the existing spillway, lots of unknowns will be revealed. Where the competent rock is that can remain. Where the fill, voids, or clay, or incompetent rock is. That will have to be removed and in-filled.

3. The fact that the new spillway engineering isn't yet done and being done in a hurry. Construction will progress while engineering and engineering double-checking is also still in-progress. I've been involved with several projects with that scenario in my career. Starting construction with hurried, incomplete designs means there will ALWAYS be various engineering revisions in the middle of construction, some of which will impact work already completed that has to be corrected. That means time and money. Additional money can be had, but time is fixed. Nature is up to bat next November, no matter what the DWR or contractors or Corp of Engineers say.

Re: Oroville Dam

Unread postPosted: Fri 15 Dec 2017, 16:31:24
by Tanada
Oroville Dam spillway failure equals failed state water policy

How much better off would California be if the fresh water spilled from Lake Oroville earlier this year had been stored instead of converted to salt water?

How far will 5.23 million acre feet of water go in California? You could irrigate the state’s entire almond crop without pumping a drop of groundwater; or provide the 29 State Water Project (SWP) contractors – a third of this water goes for agricultural users – with more than a years’ worth of water.

One could also fill Shasta Lake (4.5 million acre feet) and 19 percent of Lake Oroville, or fill Lake Oroville (3.53 million acre feet) and one-third of Shasta Lake. The worst option would be to waste it and let it flow into the Pacific Ocean.

The recent announcement that California State Water Project (SWP) contractors could receive 15 percent of requested supplies if no more rain or snow falls this winter makes one wonder how much higher the initial allocation could have been if 5.2 million acre feet of water not been released down the main spillway at Lake Oroville last winter.

By comparison, each of the three next-highest water years – 1997, 1983 and 1969 – saw a little more than two million acre feet released from Oroville Dam. At no other time in history were Oroville Dam and its spillway so tested.

This doesn’t count water that free flowed over the emergency spillway at Oroville Dam in early February, sending 200,000 people scrambling for higher ground as officials feared catastrophic failure.

Sure, some of the 5.2 million acre feet of water likely wound up in aquifers as the Feather River overflowed its banks, flooding areas that allowed for percolation, but suffice to say most of that fresh water eventually became salt water as it passed under the Golden Gate Bridge.

Mike Wade, executive director of the California Farm Water Coalition, said the Dec. 1 preliminary estimate by the California Department of Water Resources is a fair indication of what officials think of the season yet to come, particularly as Lake Oroville – the main SWP facility – is at a fraction of desired storage for this time of year due to repairs to the broken main spillway on the dam.

Today, Lake Oroville holds about 35 percent of its 3.5 million-acre-foot capacity. Depending on how winter progresses over the Feather River watershed that could either be fortuitous in hindsight or unfortunate if we return to drought conditions.

Here’s a few more amazing numbers related to Lake Oroville from the Department of Water Resources.

Feb. 6-7: Lake elevation rises 12 feet in a single day, or about 157,000 acre feet, as inflows from the Feather River exceed 100,000 cubic feet per second (CFS).
Feb. 7: Main spillway fails.
Feb. 8: 178,777 acre feet of water are added to the reservoir as the lake continues to rise more than 10 feet per day, closing fast on the 900-foot elevation of the emergency spillway.
Feb. 9: Lake levels rise another 12 feet, as 240,000 acre feet of water is added to the reservoir. Daily inflows to the lake exceed 155,000 CFS. Outflow at this time is about 30,000 CFS as officials limit outflows and consider how to handle the growing chasm in the main spillway.
Feb. 11, the lake overflows its emergency spillway and 200,000 people are ordered to immediately evacuate as officials fear the emergency spillway would fail.

This is just one example of how failure to maintain our water infrastructure can have catastrophic impacts, and why California with its 40 million people should immediately build more water storage and improve the ability to convey it where needed.

What if instead of losing all that water to the ocean we could have stored it elsewhere for groundwater recharge and irrigation?

Oroville Dam Failed Policy

Re: Oroville Dam

Unread postPosted: Fri 15 Dec 2017, 16:43:20
by jedrider
That's called INFRASTRUCTURE investment.

That's the only good use of debt.

Re: Oroville Dam

Unread postPosted: Fri 15 Dec 2017, 18:11:37
by vtsnowedin
Tanada wrote:....

What if instead of losing all that water to the ocean we could have stored it elsewhere for groundwater recharge and irrigation?

[/quote] There was and is no elsewhere to store it. When a impoundment gets full the excess flows over the spillway and on towards the ocean. Just a fact of life.

Re: Oroville Dam

Unread postPosted: Fri 15 Dec 2017, 19:30:24
by Outcast_Searcher
vtsnowedin wrote:
Tanada wrote:....

What if instead of losing all that water to the ocean we could have stored it elsewhere for groundwater recharge and irrigation?

There was and is no elsewhere to store it. When a impoundment gets full the excess flows over the spillway and on towards the ocean. Just a fact of life.[/quote]
Excellent point. To be fair to Tanada, that quote was from an article linked to -- not a direct quote, BTW.

It's too bad the vast majority of such proposals don't have a sound PLAN behind them, instead of just a feel-good "I wish it could be so", without thought to cost, WHO pays for it, viability, etc.

It's like "let's build bullet trains", as though the funds couldn't and shouldn't be used elsewhere. CA shows us lots of examples of what happens with high taxes and expenditure of lots and lots of money on what "enlightened" liberals want.

Like with most places, you get some good and some bad, but certainly no wonderful shining example of a place run so well (infrastructure or otherwise) that we should all blindly follow it, "just because".

Re: Oroville Dam

Unread postPosted: Sun 14 Jan 2018, 17:13:17
by vox_mundi
Failed Oroville Dam Spillway Designed by Inexperienced Grad Student in the 1960s


California’s Department of Water Resources was blasted in an independent report for having a culture of complacency and incompetence that contributed to last year’s near-disaster at Oroville Dam.

The full 584 page independent forensic team report is here.

The agency’s largest water storage site and the nation’s tallest dam at Lake Oroville fell into disrepair. In February, pounding rain and large water releases caused the reservoir’s spillway to collapse. A back-up spillway also failed. Fears that water would pour uncontrollably downstream prompted the evacuation of 180,000 people.

The independent panel of safety experts said the dam was badly built from the start in the 1960s. The principal designer of the spillway told the dam-safety team that he had just completed post-graduate work at the time he worked on the Oroville project decades ago, had had no previous engineering employment beyond two summer stints, and had never designed a spillway before.

Re: Oroville Dam

Unread postPosted: Sun 14 Jan 2018, 20:18:14
by vtsnowedin
That is quite a slam against graduate and post graduate students. Who else would have in hand all the history and information on the subject and know where to search out needed information. And he was certainly not the head of the California DWR (Department of water resources) so his work was certainly checked and signed off for by people with a much higher pay grade then his.
The DWR is now pointing the finger at this one individual to turn criticism away from their bureaucracy as a whole.

Re: Oroville Dam

Unread postPosted: Sat 20 Apr 2019, 18:26:14
by Tanada
Video of the new Oroville Dam spillway being tested. Good to see it is finished as this is an El Nino year like the one that caused the initial flood control problems.