When the Levee Breaks

[sparky]

"OROVILLE, Calif. - An immediate evacuation from the low levels of Oroville and areas downstream is ordered. 
A hazardous situation has developed with the Oroville Dam emergency spillway. Officials say that operation of the auxiliary spillway has lead to severe erosion that could lead to a failure of the structure.
Failure of the emergency spillway structure will result in an uncontrolled release of flood waters from Lake Oroville.
In response to this developing situation, DWR is increasing water releases to 100,000 cubic feet per second. Immediate evacuation from the low levels of Oroville and areas downstream has been ordered.
Officials are anticipating a failure of the auxiliary spillway at Oroville Dam within the next 60 minutes. 
Residents of Oroville should evacuate in a northward direction such as towards Chico."

[ERIC]

30 vertical feet of the spillway could crumble within the hour, officials say.

[ERIC]

Live streams of Oroville: http://www.actionnewsnow.com/livestream || http://www.kcra.com/nowcast

[rlown]

I sincerely hope this won't be massive, but I fear it will be. thanks for the post, just saw it on TV..

[rlown]

there's a thread.. viewtopic.php?f=8&p=115934#p115934

[ERIC]

Let's just hope it holds long enough for people to evacuate.

[rlown]

"Marysville/Yuba County now being included in the evacuation notice due to Oroville Dam emergency spillway potential failure."

Not sure how you got the well formed twitter info in, but I'll add this.

and this: http://www.pressdemocrat.com/news/66601 ... artslide=0

[ERIC]

Saw that. Relevant that Marysville is 30 miles downstream of Oroville.

[Tom_H]

Here is an article giving information on how ground level elevation has dropped in the Central Valley due to excessive groundwater extraction. It can actually be difficult for soils to recover from subsidence. As water is removed, particles compact, filling the voids, leaving less volume for new water to fill. WD is correct regarding lateral migration of water into aquifers. In many aquifers the water drawn in a well migrated laterally for hundreds of miles over a period of hundreds to thousands of years. In many aquifers water doesn't simply perc directly down and recharge the system.

http://www.latimes.com/local/lanow/la-m ... story.html

I have read articles in the past about pressure injecting excess water into aquifers in times like the present, but I just don't see how that is in any way practical.

[Lumbergh21]

Oh, guess I did not explain one thing very well. If you have a well and are pumping water from the lower aquifer, the level of the water you pump is not the depth of the well - it is water level in that well. It does not go up and down due to drops of water recharged at the well location. It goes up and down due to the pressure head, that is recharged at the edge of the Sierra. You do not actually wait for any drop of water to migrate eastward. Over pumping reduces the pressure head.

I was really surprised when I first started working on groundwater here. There are thousands!! of very large agricultural wells with an awesome cumulative effect on the aquifers. Surface water deliveries to farmers are good for everyone in that if it allows farmers to pump less, we all win because we all depend on the aquifer some way or another.

Maybe I should rephrase. How will restrictions on surface water usage help the Central Valley aquifer recover? I am not referring to restrictions on withdrawals from aquifers. The restrictions put in place over the past three years and now continuing through this year are on water usage. I have no problem with water systems being restricted to the amount of water that they have available to them through contracts with the USBR, etc. However, when the DWR decides that you are not allowed to use the water allocated to you and that the USBR agrees to supply to you, there's something wrong. The Governor says we all need to learn to conserve and adjust to this new way of life. What is the reason for conserving water in a wet year especially in a water rich part of the state? Is it to make the whole state feel the pain? Is it to increase the amount of fresh water flowing into the ocean? Or, maybe it's to increase deliveries around the delta and into Southern California? I don't know, but it certainly isn't because Northern California is in a drought. Heck, our snow pack had nearly recovered last year, and our precipitation was above average. Had reservoirs and local aquifers recovered to levels prior to the drought? No, but we certainly had more water than we were allowed to use. Now this year it has passed into the land of ludicrous. I will say, that if Oroville Dam breaks there will be drought like conditions as the summer time river flows will go back closer to normal summer time flows, which are not nearly as high as the summer flows we have artificially created through the Central Valley Water Project. Don't get me wrong, I'm not saying that those artificially high summer flows are a bad thing. Also, I'm not saying that I think Oroville dam is going to break, not entirely anyway.

I also work in the water business.