California's Lake Oroville Main Spillway Severely Damaged/Eroded. Oroville Dam's Recently Reconstructed Main Spillway Fundamentally Flawed

Based upon the evening press conference ... I put my notes in a post above ... it looks like people have a solid 2 days (from this afternoon), maybe 3, before "CRISIS" time may hit.

No need to "Panic" yet ... but do need to pay attention to what they say tomorrow night after they have examined the Spillway.

If I were in the area I would watch the lake levels ... and "IF" they are actually approaching 900 feet, say 895 feet, THEN I would be getting away from any downstream location ASAP (gives you a couple of days to pack up stuff you may want to take with you).

Link to the hourly data ... you have to hit the "Latest" blue type below the numbers to actually get the latest hourly data. The posted data runs about 2 hours behind.
[link to cdec.water.ca.gov]

(current lake level at 7 PM PST was 859.69 feet, up from 854.95 feet at 12 noon which is when they shut down the Spillway)

Well full flood capacity is the crest elevation of the dam. Most earthen dams have a slope downstream, so the water could theoretically flow over the top of the dam.

Unless the dam structure fails because it has more weight on the upstream side, that's a slope failure.

The overflow on the crest would act like a weir equation, and if it flows for too long obviously you'll get erosion of the dam on the downstream toe which could lead to failure of the embankment.

Basically, the water can flow over the top for a while, and the dam should have been designed for that but you can never test that condition so you don't know.

For you west coasters ... the 9 PM PST numbers just hit:
860.82 feet

Living here for 30+ years, I have become very impressed by the engineering that went into the design and construction of this dam. The usage of local materials in the fill, the processed rock from the gold rush dredge tailings combined with the local clay soil, painstakingly combined and compacted.

It is an engineering marvel.

Then it was turned over to bureaucrats to manage. Shameful.

There is an emergency spillway, a concrete apron designed to accommodate uncontrolled overflow. How effective? It has never been tested.

Last Edited by Crunch62 on 02/08/2017 12:21 AM

I live in central valley. Water should be directed into the canals rather than into the ocean. The farms can let it flood empty fields and refill the underground water supply which is tapped dry thanks to the drought and Nestle Water. If you read stories about dust bowl (Grapes of Wrath), you will find the farmers were not permitted to stay on land and farm it.

They should try to rush through that secession act so CA can apply for foreign aid.

I see so the spillway that OP is talking about is a regular release spillway, and then at some higher elevation is another (untested) emergency spillway?

What can it release? 200,000 cfs?

since this is glp, has anyone suggested this damage may have been 'encouraged'? enviro-terrorism? false flag to further delay sessions' confirmation?

i certainly hope this can be mitigated fast. lotta water in that lake.

to follow, hi Geo! Stay safe everyone out there.

It's probably lack of maintenance. Since the drought they probably haven't used the spillway that frequently, if they have turbines for power generation that most of the release is through the pen stocks feeding the turbines.

So when they finally get a big storm (5 year or so) then they have to use the release spillway. But cracks can develop in the spillway slabs, and when water flows over the cracks, a lot of water, it can rip the concrete up. Especially if the concrete was spalling around the joints.

Our infrastructure is old, most surface water impoundment structures like this were built in the 60s'-70s.

I suspect it can release whatever the volume is flowing over it. It is basically the overflow channel for the lake. No control or management possible. I suppose it exists to reduce erosion damage of the dam by diverting emergency flows to the side and away from the dam structure.

Ignore this post..

Last Edited by Westsail on 02/08/2017 01:05 AM

that sounds plausible. but doesn't this dam prevent some fish migration or something? seems like the enviros hated it for that. wouldn't put it past wacko enviros to minimally maintain a dam.

ok..i'll get off the conspiracy stuff...you just never know these days.

Where are you seeing this information? The lake level has risen by 5+ feet since 1 PM and the current outflow is 5112 CFS.

[link to cdec.water.ca.gov]

Oh, never mind everything I said ... looked at the timestamps wrong .. I thought the newest was on top!

Oh shit.. ok, well nice to have that data

861.33ft now

Last Edited by Westsail on 02/08/2017 01:10 AM

Yes, the construction of the dam prevented salmon from returning to their headwaters to spawn. The Feather River Fish Hatchery was constructed below the dam to mitigate this impact.

I live 4 blocks away from the river in a basement with my daughter's. Near Veatch and High. The news just indicated an inflow of 96000+ cubic feet of water and 5100 outflow, raising the river 6 inches an hour until it reaches capacity on Saturday a.m.

We're scared.

that is alot of fuckin physics goin on...entropy.......

This isn't a joke to us.

u r correct it is not a joke..i would get out of there...

According to my math, at the past rate of fill since the spillway was closed, there is 52hrs till 900' spillover stage.

And I read there is more rain in about 2 days.


02/07/2017 11:00 854.43 2868214 57545 132518 59665 31.44 13.4
02/07/2017 12:00 854.95 2875299 30009 129300 47321 31.44 13.4
02/07/2017 13:00 855.68 2885266 5420 128248 13480 31.44 13.4
02/07/2017 14:00 856.40 2895121 5153 122526 16490 31.44 13.4
02/07/2017 15:00 857.12 2904999 5107 120754 20596 31.44 13.5
02/07/2017 16:00 857.83 2914763 5110 119409 22057 31.44 13.4
02/07/2017 17:00 858.47 2923584 5158 111989 22098 31.44 13.4
02/07/2017 18:00 859.10 2932286 5185 105473 22172 31.44 13.5
02/07/2017 19:00 859.69 2940452 5135 102495 22147 31.44 13.5
02/07/2017 20:00 860.28 2948634 5172 99347 22179 31.44 13.4
02/07/2017 21:00 860.82 2956136 5112 96936 22158 31.44 13.5
02/07/2017 22:00 861.33 2963234 5158 88657 22131 31.44 13.5

Hopefully it will be alright. I'm a widow with 2 daughters and a full time student at Butte College. I can't just bug out. I'll loose my financial aid. I can't have that.
Thank you for updating this thread with good info. Thank you GLP.
We're just going to be alert and ready to leave. Is anyone else in this part of the 530? All the Best.

Unfortunately in the longer range, there seems to be several more Atmospheric River storms coming straight from Hawaii. It can still change, but this seems like it could get violent throughout the whole state of these longer range models hold.

Thoughts and prayers to everyone downstream of the Feather River. They don't call Oroville 'Orohell' for nothing.

Be safe.

Geo, do you see this as a 150/200 year storm/flood?

The last great Cali flood with Atmospheric river storms was ~1862.

I've seen comparisons, but I will wait and see on what is coming up. But this sure has been a very bad flood year that's for sure. I think we have had over 10 AR's this Winter which is completely unheard of. We still have a month or so in our wet season left.

^THIS^

The simple fact is....

Central and Northern Ca. is completely saturated with 200%+ above normal rainfall, levee's are strained, reservoirs are near capacity, and this could be just the beginning of a long line of failures on an over-stressed system and we're only half way thru winter with a long range forecast showing more of the same....