Yes, I said dams, plural - the above pic is of the Anderson Dam, just south of San Jose, which is now using its spillway.
Even if the Oroville Dam holds, the flooding down river looked exactly like what we dealt with in SC two Octobers ago. Undermined roads, drowned cars, 2-3 foot wide creeks flooding adjacent houses and businesses, usually tiny streams cresting at 15-10 ft.
The spillway on the Don Pedro reservoir in the central valley was opened around 3pm today. The water released is already spilling over roads. Dramatic images from the Toulomne Sherriff’s Department. Bob Henson at Wunderground posted today about the high rainfall totals in the southern Bay Area and high winds that will come with the back end of this storm system and affect a broad area. They are expecting lots of power outages. It will be an opportunity for folks to test their preparedness.
Yesterday, Juan Browne posted this video. He got access to the DWR spokesman. Then, he summarized their conversation in the attached 6 minute video. Highlights:
Work is progressing on the emergency spillway. Four primary areas were targeted. Work on these 4 primary areas is between 60% and 100% complete. Although work is being done to armor the emergency spillway, it will only be used as a last option when the power plant and regular spillway cannot remove enough water. [My advice to anyone downstream … if it ever gets to the point that water crests the emergency spillway, you should have gotten the HELL out while you could! Keep a close eye on water levels and set personal trigger points for actions. If you wait for an official pronouncement, there will be no opportunity to get through the gridlock to safety.]
A barge is being built below the dam’s toe in the tail water to carry an excavator that will clean out the debris from the spillway washout. This work will be done to lower the tail water so the power plant can be operated.
The power plant is not connected to the grid and cannot function until the tail water is lowered and new electrical connections to the grid are installed. Water cannot flow past the penstocks until these 2 conditions are met.
Grid power to the spillway gates has been cut. Power to operate the gates is being supplied by generators.
Weather is cooling down which should minimize snow melt for the time being. Water levels in the lake are down about 50’ from the emergency spillway crest. [Just checked https://cdec.water.ca.gov/cgi-progs/queryF?s=ORO and water level is at 852.25’ on 2/21/2017 at 1 PM PST. That’s up about 3’ since yesterday morning. Not bad, given all of yesterday’s rain.]
Grover
Now that the water emergency is over, here’s some photos showing the damage caused by the spillway erosion.
http://www.kcra.com/article/10-photos-show-extensive-damage-at-oroville-…
That spillway is 50% gone....
Here’s a close up of the damage from the link I gave above. Note how small the trucks are (on the left side) compared to the canyon that was carved out. I don’t know much about dam construction but I do know it’s going to take a lot of truckloads of filler material to repair the spillway.
http://www.appeal-democrat.com/news/repair-work-continues-at-oroville-dam/article_7c92f1fc-fe20-11e6-9b2e-c72c976f9569.html
This is a photo of about 20 people at the bottom of the Oroville Dam spillway. This thing is huge!
Base of the main spillway.
Here’s the latest video from Juan Browne dated 3/1/2017. It is about 27 minutes long. Juan shows the current work progressing to remove debris from under the eroded spillway and gives a good description of the work needed to relocate the power lines so the Hyatt power plant can be reconnected. Then, he visits other infrastructure associated with the Oroville dam complex.
Some highlights:
The washout from the spillway generated approximately 1 1/2 million cubic yards of debris.
In the day and a half that the spillway has been shut off, about 60 thousand cubic yards of debris have been excavated.
The goal is to get a channel formed so that water can flow through the Hyatt power plant down to the Feather river.
Temporary power lines have been relocated and hooked up to the Hyatt power plant. As soon as the channel is sufficiently cleared, water can once again flow through the power plant.
Water stored in the Forebay and Afterbay is being released at 2500 CFS into the Feather River to keep the river alive.
There is at least 1 week of water storage remaining in these bays.
There is an enormous amount of work remaining to be done. If a channel can be opened enough for the power plant to work, water levels in the reservoir can be moderated by using this release mechanism. (I heard that only 5 of 6 turbines were functioning. That might limit discharge rates.) While the power plant operates, crews can still work on removing debris from the spillway damage.
With 1.5 million cubic yards of debris and 40,000 cubic yards/day of removal, it would take almost 40 days to remove the debris pile. If the weather holds, this is very doable. The normal wet season ends in about a month. After that, snow pack melt will be the issue of concern. For now, the future looks much better than it did just a couple of weeks ago. Of course, mother nature always bats last.
Grover
PS - sand_puppy, that link in your post #71 is a great summary in pictures of the calamity. Thumbs Up!
To underscore davefairtex’s point, as a software project manager, I have many times seen engineers, when asked to state an estimated project delivery date, say “Well, if everything goes right, it will be ready by XXX.”
Of course, assuming that everything goes right is assuming, by definition, a statistically improbable scenario.
And maybe that scenario is about as probable as assuming that everything goes wrong 
.
But it’s good to look optimistic to the Big Boss. And I don’t ever recall hearing the Big Boss reply, “What if not everything goes right?”. Much harder (and scary) question to answer.
Here is the drone video mentioned in the video posted above.
Here is the latest Juan Browne video for those of us who can’t get enough. This video is 7 minutes long. It is only kitchen table shots - no field report. Here are the highlights:
The Hyatt power plant is marginally operational now. That means that electrical lines have been relocated and that the debris filled channel has been excavated sufficiently to allow some water to flow. As of the time of video posting, about 2,500 CFS were flowing. The goal was to have it ramped up to 3,000 CFS by the end of the day. With only 5 of 6 turbines available, max flow is about 14,000 CFS
Reservoir elevations about 849 feet. Still have about 50 feet of freeboard.
Debris field quantity has been re-estimated to 1.7 million cubic yards. So far, 168,000 cubic yards have been moved - about 10%.
Some temporary repair work is being done on main spillway blowout. The immediate goal is to minimize head cutting. If spillway is needed, flows will likely be ramped up to 40,000 CFS (or more) to move water off spillway and diving into plunge pool in order to minimize head cutting erosion on the busted spillway.
Precipitation for the last few months has been a “100 year event.”
Emergency evacuation warning remains in effect. Will be removed when 1) emergency spillway has been armored (complete), 2) power plant is fully functional, and 3) reservoir elevation is at 850’ or lower.
Getting water to flow through the power plant is a BIG accomplishment. Work will continue to excavate the debris field. The goal is to have enough water exit the power plant that reservoir levels can be kept in check. They don’t want to use the main spillway unless absolutely necessary.
Grover
Here is a 3 minute video of work being done over the weekend. Crews are continuing to remove debris out of the river channel. Others are spraying shotcrete under the busted spillway to keep it from head cutting and eroding more when they need to release water down the spillway.
There is a short speeded up sequence of debris excavation at about 1:40. The heavy equipment looks like just so many ants. That made me wonder what would have happened here if the economy wasn’t functioning. Where would the fuel to operate the equipment come from? Who would stay behind to operate the dam if there weren’t any monetary incitement? Do the operators have a plan for a lights-out scenario?
I read that this was a “hundred year storm.” If so, it should occur on average once every 100 years. Will we be ready the next time this happens? Will we have a functioning economy/available fuel to repair the damage and prevent more catastrophic damage? What if the next storm is a 1,000 year storm or a 10,000 year storm … or bigger and more widespread? What will happen to anyone unfortunate enough to be downstream of this dam or any other dam when it bursts?
Grover
Here is Juan Browne’s latest video dated 3/9/2017. It has more good news. Water is flowing through the Hyatt power plant. Enough debris has been removed from the river channel to allow at least 4 of the 6 turbines to operate. (Latest DWR data has 11933 cfs outflow and reservoir elevation at 859.92’.) Weather is also cooperating with cold nights, mild days, and no rain in the forecast. New arbitrary reservoir elevation trigger for opening spillway is set to 865’. (It was arbitrarily set to 860’ until this latest change.)
https://cdec.water.ca.gov/cgi-progs/queryF?s=ORO OROVILLE DAM (ORO) Station comments: 02/23/2017 Outflow from Oroville includes all releases from the Oroville Dam (i.e.: Hyatt, spillway, low flow outlet), while River Release (RIV REL) pertains to the Oroville Complex as a whole which includes any releases from the Diversion Dam gates and Thermalito Afterbay River Outlet.Now for the bad news. Current estimates are that the emergency repairs are costing $4.7 million per day. Fortunately, 75-90% of the cost will be reimbursed by FEMA. Whew! And I thought someone would have to pay for it. GroverQuery executed Thursday at 16:26:24
Provisional data, subject to change.
Select a sensor type for a plot of data.
EarlierDate / Time
RES ELE(PST)
FEETAF
CFS
CFS
CFS
INCHES
VOLTS
03/09/2017 05:00
859.592939067
8730
5997
4957
39.48
13.4
03/09/2017 06:00
859.642939760
8781
7591
4956
39.48
13.4
03/09/2017 07:00
859.682940313
8727
7731
4936
39.48
13.4
03/09/2017 08:00
859.712940729
8725
6226
4969
39.48
13.4
03/09/2017 09:00
859.752941283
8690
6794
5616
39.48
13.4
03/09/2017 10:00
859.772941560
8716
6283
5637
39.48
13.4
03/09/2017 11:00
859.802941976
10314
4309
5646
39.48
13.4
03/09/2017 12:00
859.832942392
10260
5247
5638
39.48
13.4
03/09/2017 13:00
859.852942669
10260
3490
5623
39.48
13.4
03/09/2017 14:00
859.882943085
10286
4657
5682
39.48
13.4
03/09/2017 15:00
859.912943500
11882
15831
8481
39.48
13.4
03/09/2017 16:00
859.922943639
11933
15098
8537
39.48
13.4
http://www.mercurynews.com/2017/03/09/oroville-dam-dwr-says-repair-cost-estimated-at-4-7-million-per-day/ On Wednesday afternoon, Assemblyman James Gallagher, R-Yuba City, said he was expecting to hear about costs accrued, as the DWR met with the Federal Emergency Management Agency earlier Wednesday to discuss repair and maintenance costs related to damage of the spillways. Curtis Grima, Gallagher’s chief of staff, later said in an email that according to conversations with DWR officials, the estimated daily average cost is $4.7 million. It is estimated that between 75 percent-90 percent of the cost will be reimbursed by FEMA, Grima’s email said.
Here’s Juan’s latest video (about 17 minutes) dated 3/10/17. He talks about the current state of the situation - river elevation about 860’, flow through Hyatt power plant near 13,000 CFS, about 715,000 cubic yards of debris from spillway washout removed, and all operations are continuing. With the snow melt, there is more inflow than outflow. The spillway will likely be operated again to keep water from flowing over the emergency spillway.
He also delves into some of the specifics of the dam. It is an interesting video.