ULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SACRAMENTO CA
435 PM PST SUN FEB 12 2017
THE NATIONAL WEATHER SERVICE IN SACRAMENTO HAS ISSUED A
* FLASH FLOOD WARNING FOR...
A DAM FAILURE IN...
SOUTH CENTRAL BUTTE COUNTY IN NORTHERN CALIFORNIA...
* UNTIL 415 PM PST MONDAY
* AT 419 PM PST, DAM OPERATORS REPORTED A HAZARDOUS SITUATION IS
DEVELOPING WITH THE OROVILLE DAM AUXILIARY SPILLWAY. OPERATION OF
THE AUXILIARY SPILLWAY HAS LEAD TO SEVERE EROSION THAT COULD LEAD
TO A FAILURE OF THE STRUCTURE. FAILURE OF THE AUXILIARY 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 AREAS
DOWNSTREAM IS ORDERED. FROM OROVILLE TO GRIDLEY...LOW LEVEL AREAS
AROUND THE FEATHER RIVER WILL EXPERIENCE RAPID RIVER RISES.
THIS IS NOT A DRILL. THIS IS NOT A DRILL. REPEAT THIS IS NOT A
DRILL.
* LOCATIONS IMPACTED INCLUDE...
OROVILLE, PALERMO, GRIDLEY, THERMALITO, SOUTH OROVILLE, OROVILLE
DAM, OROVILLE EAST AND WYANDOTTE.
Uh oh. Someone who’s been keeping track of this and knows more than I do, please correct me if this is not the situation:
1. The main spillway was showing signs of erosion and they used the auxiliary spillway in addition to ease the pressure;
2. The auxiliary spillway is now showing signs of erosion and they opened the main one back up to ease that pressure.
3. Failure of the auxiliary spillway structure will result in no control whatever.
4. This would not constitute failure of the dam but would still be a very serious flooding situation.
5. The erosion in the main spillway is likely to get worse.
Is this the case? Could I get some expert comment, please?
That is horrible... I hope you are safe and same for all in harms way. I can’t even begin to imagine.. and the animals, too.
“THIS IS NOT A DRILL. THIS IS NOT A DRILL. REPEAT THIS IS NOT A
DRILL.”
Damn...
I was afraid the water rushing over that “emergency spillway” would cut right through it. Prayers up.
The Aux spillway started operating at about 8am yesterday. Peak depth of lake was reached last night, and it’s down a bit from that now. Inflow is way down from where it was in the last two days, so what they need to do is draw about another foot of water out of the lake and it’ll stop flowing over the aux spillway. The problem is that the only way to accomplish that is to increase flow through the main spillway, which is where the original problem is located. They’d cut back flow there yesterday because of the increase in size of the sinkhole in the waterway. Cranking it up to 100,000 is going to cause that thing to break up at a rapid rate, but with the alternative being unlimited flow, that’s what they “gotta do”. Time for some breath holding through the night now.
Thanks Janet Janet!
Links
Confirmed by tweet:
https://mobile.twitter.com/corinhoggard/status/830944293485371392/photo/1
NWS site has flood warning (I.e. imminent)