Posted on 02/09/2017 9:30:51 PM PST by blueplum
Update, 7:15 p.m. Thursday: The situation surrounding the damaged spillway at Oroville Dam has escalated into a crisis, with state water managers hoping they can dump enough water down the badly compromised structure to prevent the states second-largest reservoir from pouring over an emergency release point that has never been used before. Flow rates down the collapsing spillway were increased late Thursday morning to 35,000 cubic feet per second. The result was a spectacle of churning mud and water and the further damage to the concrete structure. [snip] Officials at the media briefing repeated further reassurances that the integrity of Oroville Dam, one of the largest in the United States, has not been affected by the spillway collapse. Butte County Sheriff Kory Honea said that while local emergency agencies are preparing for evacuations downstream of the dam, he didnt believe the spillway situation posed an imminent threat.
(Excerpt) Read more at ww2.kqed.org ...
Tapping a flow rate of half a million gallons persec? Lots.
The dam is in no danger of failing. The problem is with a spillway alongside the dam that is used for water release. They will use that spillway as long as possible. If there is a major amount of water flowing into the dam that the spillway can not handle, then the emergency overflow will be used. Imagine your bathtub filling up...the emergency drain would be when the water goes over the top and onto the floor....Still nothing wrong with the bath tub...same with the dam. The integrity of the dam is just fine, its just that the spillway collapsed and eroded due to time and water. We will just be fine. The Bay Area will not get flooded as its nearly 200 miles away.
We thank you for your prayers though as all prayers are helpful and appreciated.
That is spot on.
A lot less than 20000 cubic feet per second...
Right.
The big immediate problem is turbidity of the water which is threatening a major hatchery just downstream. We could be looking at a lot less salmon in the food supply...
http://www.sfchronicle.com/bayarea/article/Uncharted-territory-as-Oroville-Dam-10921941.php
Right now we are ten feet from the top. Sometime tomorrow night near midnight it might well flow uncontrolled over the top. They are trying to release 50K cfs, but water is coming in at 191K cfs. Hence the problem. If it spills over the top, then the dam officials will have a hard time with dam flood control
Stay safe, abigkahuna. The dam itself probably won’t fail, but they’ve got to let that water out and the only place to put it is into the river. Along with concrete, boulders, trees and assorted other goodies that wash away as the regular spillway breaks apart (which is what it looks like the dam people are going to allow). That makes for some nasty compressed water headed downstream.
They have been moving the fingerlings (about four million or so) into tanker trucks and moving them down into the Thermolito Forebay for protection. We get salmon runs in the Feather River and its pretty cool to see them coming upstream to the hatchery. Folks line the banks with fishing poles hoping to catch one of those big boys/girls
The only problem might be downtown. It happened around 20 years ago when the river crested the levees and flooded the streets. It should be all good though as we are headed for clearing weather on the weekend.
Another FR Oroville spillway thread: http://www.freerepublic.com/focus/f-news/3523218/posts
The emergency spillway (just to the North of the regular spillway) is lower than the dam...the water goes over there first.
Satellite shot (emer. spillway is just to the left of the regular one in this shot): https://goo.gl/maps/HNijdc4g8qp
Yup, I know as I used to walk the top of the dam everyday till it was closed off after 9-11. 165 miles of shoreline. Gorgeous area. Don’t move here.
Too late, was born in Calaveras County...currently living outside of “FR HQ” (Fresno)...we are planning our escape from Kalifornia...probably after our parents pass on.
The top of the dam was open to traffic in Nov., 2014 (we drove across...that is also how you get to a main boat launch ramp). Must have been a temporary closure in 2001.
Yeah, looks like somewhere around 700,000 gallons an hour. About 2 acre feet.
Some closeup shots of the damage on Facebook:
https://www.facebook.com/photo.php?fbid=724942224338895&set=pcb.724942281005556&type=3&theater
It’ll take more than a couple bags of “Quikrete” to fix that! They’ll probably let it scour down to bedrock and fix it in the summer/fall.
Those great explanatory photos. Thanks!
Infrastructure. Trump wants to spend on infrastructure.
Others are in danger of breakage as well. Near Napa is the spillway near Conn Dam which is being heavily tested.
Upside is.. the drought’s over.
Wiki: Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California in the United States, at 770 feet (230 m) high.
earthfill - that explains it.
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