Several simultaneous projects are planned or underway to bring the power plant back online, restarting the bottom outflow (17,000 CFS max).
Building a new road to allow heavy equipment to access the pool at the bottom of the main spillway
Clearing the debris from the pool using heavy equipment (new road) and barges
Moving power transmission line towers higher up, to safer ground
Restringing the wires to the new tower
(source)
Regarding the bottom photos, it appears to me that there are 2 separate sources.
Left side - Clear water, indicating no erosion. This appears to be sourced somewhere near the top, flowing through the gravel layer between the spillway side wall and the earthen hillside, emerging through the side drains.
Right side - Brown water, indicating erosion. This emerges from the bottom lip of the hole in the concrete. It has somehow flowed across earth, either under the concrete spillway or along the right side, where the gravel and earth have been eroded away
Both sources must be above the hole, but where? The clear water is less of a concern. The brown water is really scary. As the dam expert noted in one of his outstanding Linkedin posts, the crack in the bottom of the spillway concrete likely was the result of water running under it undetected, carrying away the earth underneath it, leaving it unsupported. Then when the weight and impact of the rushing discharge water hit it, it failed, leaving a hole. This had nice jagged edges and dirt underneath, perfect for the fast moving 100,000 CFS stream to scour it, eventually completely removing the bottom part of the spillway.
Is there a leak under the spillway head gates? We should know pretty quickly as the water drops to the level of them and thus quits flowing down the spillway, allowing easier inspection.
The bottom photo in post #37 is a photo of the spillway after the first trial. The area is currently significantly more eroded. In this photo, there is water sheeting off the intact spillway into the void. There is water coming from the upper side drains (on both sides) and possibly also from a not-completely-sealed spillway gate. There may be an additional subterranean source. The water is likely mixing with the slumped soil from the erosional feature slightly above the spillway head scarp on the right side. This muddy water splits with some of it returning to the bottom spillway and most of it forming its own channel to the right of the spillway. I agree with you that muddy water indicates erosion.
Looking at more recent photos, I interpret the reddish colored rock as being more weathered and thus weaker. Water has done its job and removed what it could. Although more erosion may occur, the effluent is now running much clearer. I agree, that is a good sign. The bottom of the spillway is still intact as evidenced by plumes from water impacting the energy dissipater blocks at the bottom of the spillway.
The older photo (bottom photo in post #37) shows reddish color behind the spillway head scarp. If the red color indicates weaker rock, that rock may have weathered/eroded from under the spillway. Surface water percolating through a weak seam could do that. That could have been a source for the original weakness of the spillway. The rock may have been competent and unweathered when the spillway was built. Different chemical mixtures in the granitic source rock weather at differing rates. I've worked with slaking shale that was very difficult to chisel, but crumbled under hand pressure after being exposed to air for a day. Not that this rock was like that, but stranger things happen. The rock in the hillside certainly isn't homogeneous.
Also, that drawing showing the underground power plant is more or less for illustrating the pertinent components of the dam. It definitely is not to scale. The power plant would be much, much smaller and much closer to the toe of the dam. I'm only pointing this out so laymen won't get the wrong idea.
I'm glad they are working on several fronts, particularly getting the power plant operational. Without that functioning, the only "safe" exit is through the spillway.
Grover
For what it’s worth, I’m a retired safety engineer. OSHA is necessary.; there are employers who would put their workers at extreme risk. And the regulations go through a review process where industry weighs in. So yes. I will be writing the new administration about keeping those regs.
Both the 0z and 6z (below) GFS runs show plenty of rainfall over the next 7 days. The Canadian model agrees. I can’t see the European QPF maps, but it looks very wet as well. I guess they have things stabilized now, so we’re probably beyond the critical zone, with lesser chance of failure going forward, just based on some of the comments.
My apologies, in an earlier post I repeatedly stated the level of the main spillway inlet as 860’ versus the actual value of 813.6’. Dyslexia failure!
As of Feb 15, the level of the lake is about 870’, about 60’ above the main spillway inlet, and is dropping about 9’ / day. (source) So with no increased input, it would take about 7 days to drop to the level of the main spillway inlet. That time will be extended by the amount in increased intake brought about by the coming storms.
DWR chart:
My projection, based on the DWR data above and assuming no storms and linear drop for simplicity. The storms will slow the rate of decrease in elevation. The projection flattens out at 813.6’, the level of the main spillway intake. Whenever the hydro power plant comes back online it will be able to decline below that, at about 1/6th the rate (17,000 CFS versus 100,000 CFS).
For what it's worth, I'm a retired safety engineer. OSHA is necessary.; there are employers who would put their workers at extreme risk. And the regulations go through a review process where industry weighs in.
I disagree. There are 3 parties involved that have a vested interest and an OSHA person isn't one of them. You have
Employee - obviously wants to not be hurt and still be able to work.
Employer - who want the job done, doesn't want to have to retrain an employee or possibly pay for injuries depending on their agreement with the Employee.
Consumer - the person who is buying what ever the Employer is selling. You get to vote with your pocket book if you want better care of the Employee.
The OSHA inspector has no vested interest except as a consumer, the only power they have is through acts of violence by the state. This, just like anything done by the state, no matter how good sounding, is simply another potentially unsustainable distortion. It has the same impact as minimum wage laws in that it raises the cost of labor to where what ever is being done becomes not worth doing, gets automated, or gets pushed to anther jurisdiction.
Wendy S. Delmater wrote:
So yes. I will be writing the new administration about keeping those regs.
As you are doing that, please keep in the back of your mind, what you are saying is I'm asking someone to use violence against the Employer and/or the Employee on my behalf. To ultimately kill them by sending men with guns if they don't want to do things my way.
Or you could offer your services to an Employer by explaining to them how you can help save them money (better employees with less cost, less turn over) or you can help improve their image with their consumer. Or you could talk to groups of the employees and explain how to improve safety in their jobs. These are voluntary acts and don't involve threat/use of violence.
Everyone should keep that last point in mind. Anything you ask the state to do on your behalf is advocating violence by proxy. Is it worth it, that's up to you, but at least understand what your asking for and does it fit within your moral belief system. If you aren't willing to pick up a gun, go to the Employee and Employer and shoot them if they refuse to comply, then you shouldn't be asking someone else to do it for you. I see truly compassionate people,and I know your one from your writings on this site, that don't think about what they are asking.
As you are doing that, please keep in the back of your mind, what you are saying is I'm asking someone to use violence against the Employer and/or the Employee on my behalf. To ultimately kill them by sending men with guns if they don't want to do things my way.
Or you could offer your services to an Employer by explaining to them how you can help save them money (better employees with less cost, less turn over) or you can help improve their image with their consumer. Or you could talk to groups of the employees and explain how to improve safety in their jobs. These are voluntary acts and don't involve threat/use of violence.
Everyone should keep that last point in mind. Anything you ask the state to do on your behalf is advocating violence by proxy. Is it worth it, that's up to you, but at least understand what your asking for and does it fit within your moral belief system. If you aren't willing to pick up a gun, go to the Employee and Employer and shoot them if they refuse to comply, then you shouldn't be asking someone else to do it for you. I see truly compassionate people,and I know your one from your writings on this site, that don't think about what they are asking.
Or we could allow labor to unify itself, instead of outlawing such organizations of the working classes. Better yet, let's go back a time when the employees were treated with such horrible disrespect and subjected to even more horrible working and living conditions that they joined communist organizations by the millions. Better times, those were!
Hi rhare
I’m not sure it’s as clear cut as that. As I railway engineer I am licensed by the Institute of Railway Signalling Engineers to undertake Signalling Design Work. When doing so I must adhere to safety standards that have been developed over decades of railway accidents and accumulated experience that has followed the evolution of signalling systems. Expecting the three bodies you listed to remember and implement over a century of best practice without referring to enforced safety principles is a little naive. I have been in situations where I have had to point to the relevant safety standard and say “No, you can’t do that,” to the client, quoting the standard to back up my justifications. Removing that safety net would only spell trouble. And no guns were required.
DaveF posted something a while ago called the ‘normalisation of deviance’ referring to the Deepwater Horizon oil spill. Sure the people involved suffered reputational damage and prosecution, but that alone didn’t clean up the 4.9 million barrels of oil polluting the Gulf of Mexico or bring back the 11 lives lost, in addition to the wildlife destroyed.
Wendy - write away!
Regards,
Luke
Here is a 12 minute video focused on the Oroville dam and projected reservoir levels based on weather precipitation models. The first couple of minutes gives a summary of the situation (very worth watching.) The rest is interesting to watch, but a bit hyperbolic. A slight shift in the jet stream and everything changes - better or worse. The long term weather models just aren’t that good. The videos show the scale of erosion below the spillways very well. The huge equipment being used looks miniscule.
He mentions some really sound advice that I concur completely. If you're downstream of Oroville and the dam fails, your current existence will be over. Whatever you take with you is what you will have. The swath of devastation won't just be confined to the Feather River corridor. You need to evaluate the potential impact to you. A wall of water just a few feet high can cause enormous damage to unreinforced structures. Remember the videos of the Japanese tsunami?
Frankly, if you can't do anything about it, it isn't worth worrying about either. It is best to assess your personal situation ahead of time, decide what possible options you have, and then choose trigger points that will cause you to act in a certain manner. For instance, if reservoir levels are rising fast enough that water looks like it will crest the emergency spillway, you better be going and have somewhere to go!!!
Officialdom will not give you warnings soon enough to matter. They won't want to cause an unwarranted panic. If/when warnings come, there simply aren't enough highway lanes to evacuate that large of an area. Factor that into your plans.
If the dam breaks, lots of things that all of us currently take for granted will change. Transportation and utility lines will be broken for a considerable distance. The major interstates (I-5 and I-80) will be severed, hampering any efforts to get help to those who need it. Think of Katrina's devastation on steroids. Southern/Central California gets lots of water from Northern California. If those facilities are destroyed, what impacts will be created?
For the rest of us in the world, there will be fewer options at the grocery stores. Some pharmaceuticals may not be available for quite a while. Consider getting your medical needs up to date. Do you like olives? You might want to stock up. What about other currently abundant products? How long will those be abundant in a panic? It is prudent to plan ahead. It is hoarding when supply lines are cut.
California's finances are already on shaky legs. A dam break would bring it to its knees (at a minimum.) Will there be enough energy to rebuild the area? Look at Katrina and the efforts necessary to bring it to its current state. That was back when debt loads were considerably lighter at all levels of government. Bottom line, it will impact us all to some degree.
Grover
OMG!!
This is my town, lived here all my life. We never got much from having the Dam over our heads except when Dam comes up for re-licencing, then Oroville tries to get some $ for Environmental and recreational /park projects. We had some very nice parks all along the Feather River; nice fish hatchery, Athletic fields… All are wiped out now. Levies are breaking and orchards flooded. Fish and wildlife destroyed. People are upset and resentful due to the terrible losses, and distrust of authorities due to feeling we are not being told the truth about what is going on and what may happen in the coming week.
At least our bags are packed now. Better than sitting in the restaurant, hearing the sirens go off and an evacuation order to immediately run for your life. Folks dropped their fork, left plates of food uneaten, jumped in the car and TRIED to leave town. But then had to stress out wondering if a wall of water was going to materialize in their rear view mirrors while hopelessly stuck in traffic for hours trying to get out of the flood zone with 200,000 other people on the roads.
Yup, Fun Times in Oroville. My town will never be the same again.
Yes he really said this at the press conference on Feb 13, after both spillways had sustained massive erosion and, in the case of the main spillway, massive structural damage as well.
Video link is here. He starts speaking at 3:48. Remarks regarding the erosion, including “I’m not sure anything went wrong”, start at 8:10.
That is followed immediately by a question regarding the 2005 relicensing concern about the lack of concrete below the auxiliary spillway. He said he was unfamiliar with “that documentation or conversation”!
You can sleep well at night, the dam is in competent hands, and they are telling nothing but the truth.
Saying the reservoir has receded enough to handle inflows from approaching storms, operators at troubled Oroville Dam said Friday they would continue to dial back releases from its cracked main spillway in hopes of easing pressure on the Feather River and levees downstream.
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In addition to relieving pressure on downstream channels, DWR is hoping that dialing back the punishing flows on the damaged main spillway will allow cranes and barges to safely operate in the channel below. The aim is to start digging out a massive pile of concrete, trees and other debris that has accumulated in the channel since the main spillway fractured. The debris has clogged the channel below the dam, raising water levels to the point that its power plant – the dam’s primary release outlet outside of flood season – can’t operate.
Saying the reservoir has receded enough to handle inflows from approaching storms, operators at troubled Oroville Dam said Friday they would continue to dial back releases from its cracked main spillway in hopes of easing pressure on the Feather River and levees downstream.
About those slowing flows...I'm wondering if it's that as the water level gets closer to the spillway finally elevation if the water pressure has not reduced enough to slow the flow?
Less 'head' and less pressure = lower flow?
About those slowing flows...I'm wondering if it's that as the water level gets closer to the spillway finally elevation if the water pressure has not reduced enough to slow the flow?
Less 'head' and less pressure = lower flow?
Chris,
If that were the case, the discharge flow rates would be smoother rather than stair stepped as shown in the graph in post #55. It looks like it is being controlled by opening/closing the spillway gates. I question the precision that their outflow numbers imply. 69854.0 implies that their margin of error is less than 0.1 CFS (about a gallon per second.)
Grover
Hearing reports of other dams beginning to experience pressure. There are numerous reports of flooding, power outages, sinkholes, mudslides, and trees down throughout the state. Looks like several more storms are still on tap before they get a break. This would be a really bad time for a strong quake out there.