BREAKING: Oroville spillway collapse threat lessens as 160,000 evacuate, clogging roads

[brooklynite]

Source: Sacramento Bee

Lake Oroville water levels have fallen to 901 feet, the level at which water flows over the emergency spillway, state figures from 8 p.m. show.

That means little or no water is likely coming over the emergency spillway – and the threat of collapse due to erosion has diminished said Joe Countryman, a member of the Central Valley Flood Protection Board and a former engineer with the U.S. Army Corps of Engineers.

Water coming over the top of the emergency spillway is likely the main factor in its erosion, Department of Water Resources spokesman Chris Orrock said Sunday night.

Now, officials should be able to start assessing damage to the emergency spillway as it begins to dry. “They are going to dry out the emergency spillway area,” Countryman said. “They are going to start the repair work.”

Read more here: http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html#storylink=cpy

Read more: http://www.sacbee.com/news/state/california/water-and-drought/article132332499.html

[braddy]

1. This is encouraging.

[NutmegYankee]

2. The main spillway was opened and is finally lowering lake levels.

Another hour or two and the water will stop spilling over the emergency spillway and the state can rebuild the ground next to the foundation.

[herding cats]

3. It's no longer going over the auxiliary spillway and they're working on temp repairs now!

A real tragedy might just have been averted.

The people below Oroville are still in imminent danger of serious flooding, however. Lake Shasta is releasing at over 70 cfs, and that coupled with the excessive release from lake Oroville (upwards to 125k cfs) is a danger. The two merge on the areas below Oroville.

Granted, the repair may not work and more rain is coming. But, for now the worst case scenario has been averted and it's looking hopeful.

[kysrsoze]

4. They're not out of the woods yet. There's an awful lot of rain coming later in the week. :(

[StrictlyRockers]

6. The weatherman is predicting heavy rain for a week straight...

The weatherman is predicting heavy rain for a week straight starting on Wednesday.

So yah, I'm worried. They are far from out of the woods.

https://www.wunderground.com/us/ca/oroville/

[DallasNE]

10. They Need To Retain The High Releases

To try and keep water from going over the spillway while repairs take place.

[kysrsoze]

11. Wow, i knew there was a lot of rain coming, but not that much. I'm worried for everyone downstream.

[Hortensis]

13. Yes. If only they could have taken their homes with them.

Don't suppose 160K people will be allowed to return to pick up more possessions during this interim.

[StrictlyRockers]

5. Rachel Maddow's report from Friday on the #OrovilleDam situation

http://www.msnbc.com/rachel-maddow/watch/oroville-dam-in-crisis-raises-alarm-in-california-874905667526

ICYMI: here's Rachel Maddow's report from Friday on the #OrovilleDam situation heading into this weekend:

[progree]

8. Excellent, very educational. Especially near the end where she shows the hole

in the main spillway (revealed when they temporarily stopped the water flow), and how the water flow is making the huge hole larger, but they have no choice but to continue to use the spillway to drain water from the lake.

[citood]

7. More snow will melt tomorrow

[AngryAmish]

16. 4 inches of rain later in the week

[citood]

18. That would be devastating

"4 inches of rain later in the week"

Ignoring the element of time (or snow melted by that rain):

Basin: 3,600 square miles

Volume of water @ 30% runoff: 230,000 acre feet

Surface area dam: 16,000 acres

Capacity available if they're able to draw it down 10 feet before rains: 160,000 acre feet

Deficit: 70,000 acre-ft (3 million cubic feet)

Outflow capacity undamaged dam: 250,000 cfs

Time needed to flow at full capacity, without involving auxillary spillway: 8 hours.

I've read that the normal spillway was only going at half capacity before, which would yield 16 hours necessary to clear storm.

Can the normal spillway (with crater) rip for an additional 16 hours? Since its closer to the dam, they may again let it go over the auxillary. Yikes.

[jeffreyi]

9. The main spillway is looking bad

And they have to keep using it because using the emergency spillway obviously didn't work. A big chunk of adjacent hillside blew out in the last 24 hrs or so. I hope the thing can hold out until plan b comes along, whatever the heck that is. I wonder what the main spillway will look like tomorrow.

[olddad56]

12. the main spillway is dumping 100,000 CFS now...

and they seem optimistic that they can keep up that flow. The lake needs to drop another 50 ft before they can attempt a temporary repair on the emergency spillway. They seem confident that the Feather River can handle the output. We will see.

If the expected rain that is suppose to begin on Thursday is heavy, I think we are screwed.

I live in Sacramento, my sisters and all of their families live in Marysville and Yuba City. They were ordered to evacuate around 5 or 6 this evening. The evacuation has been a nightmare. Gas stations that had long, long lines have run out of gas. The traffic was so heavy earlier this evening that people couldn't get out of town. My sister and her husband had been in their car for almost 3 hours and had not even been able to get onto hwy 20 leading out of town. They had traveled about 10 blocks from their home in that time. One of my nephews was stuck in traffic and almost out of gas the last time I talked to my sister. In the towns near Oroville, all of the hotels and motels are full. There are many emergency shelters opening up in all of the towns surrounding that area.

I live in Sacramento, and if the storms coming in later this week are suppose to be heavy, I'm leaving town. If you wait until you are ordered to evacuate a city the size of Sacramento, you would never be able to get onto an on ramp. I'm keeping a bag packed and my car full of gas.

Lake Oroville feeds the Feather River. At Marysville, The Yuba river dumps into the Feather, about 20 miles north of Sacramento, the Feather dumps into the Sacramento River which is fed by Lake Shasta. In Sacramento, the American dumps into the Sacramento. The American is fed by Folsom Lake. All of these lakes are close to capacity, all of the rivers are already running very high. The Sutter Bypass is full, the Yolo Causeway is full. San Luis Reservoir, which is fed by the California Aqueduct, coming out of Folsom Lake is full, the other, smaller rivers like the Consumes and Mokulome are at flood stage.

There is just not much room left anywhere for more runoff, several days of rain are forecast for later in the week and the snow pack in the Sierras is 153% of normal with high water content.

This is all coming on the heels of a long drought.

Maybe Mr. Trump is wrong about climate change being a hoax. In fact I think Mr. Trump is a hoax.

It is going to get very interesting later this week.

[BumRushDaShow]

15. If the West Coast (jet stream) ridge gets knocked back down again

hopefully the temps will drop in the mountains and start to re-freeze some of that melting snow in the Sierras.

[AngryAmish]

14. I have no idea why everyone's hair is not on fire about this.

[nikibatts]

17. I feel as you. I can't seem to get the current news on-line.

Everything seems delayed streaming. Anyone have a link to live news updates from Cali?