With Oroville Spillway Damage Spreading, Officials Prepare for Reservoir to Overflow

KQED TV ^ | 09 Feb 2017 | Staff writers

[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 state’s 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 didn’t believe the spillway situation posed an imminent threat.

[Axenolith]

21 mile dam north east of Elko failed a couple days ago.

[yawningotter]

From what I can tell, the spillway is separated from the main dam by a section of natural terrain. That should provide a buffer against the water rushing out of the spillway, so long as there is a good rock foundation underneath. That is probably why they put the spillway where they did.

[blueplum]

update on Reno and Lake Tahoe area conditions:

http://www.rgj.com/story/news/2017/02/09/weather-service-expects-flooding-sparks-6-pm/97720708/

[keat]

A debris boom on the upper arm of Lake Don Pedro preventing trees and dead wood , torn loose be the heavy flow in the Tuolumne River, from floating into the main part of the lake.

Boaters remain wary of collisions with "dead head" logs. Floating inches below the surface and weighing up to 800 pounds,these invisible hazards can destroy a boat at just about any speed.

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WILTON — Three levees along the Cosumnes River were breached Friday night at Pear Lane, Peach Lane and Green Road.
http://fox40.com/2017/02/10/cosumnes-river-levees-break-flooding-rushes-into-wilton/

Water levels are also rising in local bodies of water. Locally, rivers such as the Sacramento River (at Tehama Bridge, Vina Woodson Bridge, and Ord Ferry) and the Yolo Bypass (at Lisbon) are at the flood stage, while rivers such as the Sacramento, Yuba, Cosumnes, and San Joaquin rivers are at the monitor stage. 
Emergent water levels have been noted at Arcade Creek near American River College (74.81 feet, one-and-a-half feet below flood stage) and near Wilton (73.5 feet). Dry Creek West at Elkhorn has also reached the monitoring stage with reports of water levels at 45 feet.
http://www.capradio.org/articles/2017/02/10/thunderstorms,-potential-floods-expected-friday-additional-snowfall-continues-at-higher-elevations/

[blueplum]

ALL:

Feb 12, 5:45pm California time

Evacuation order for those below dam - head for higher ground (Chico). River path: Yuba County - head east or west

http://www.latimes.com/local/lanow/la-me-ln-oroville-update-20170212-story.html