Emergency: California’s Oroville Dam Spillway Near Failure, Evacuations Ordered

Breitbart ^ | Feb 12, 2017 | Joel B. Pollak1

[janetjanet998]

The California Department of Water Resources issued a sudden evacuation order shortly before 5 p.m. Sunday for residents near the Oroville Dam in northern California, warning that the dam’s emergency spillway would fail in the next 60 minutes.

The Oroville Dam is the highest in the nation.

[meyer]

It will take that much to dig out Moombeam Canyon...

LOL - Moonbeam Canyon! :)

[KC Burke]

You must have missed my copyrighted up-thread analysis. I named the sideways gouge Moonbeam Canyon AND I stipulated that the only appropriate backfill for the canyon is (grip your chair arms) BULLET-TRAINS.

You only have to attribute it to me on you first theft. After that, it’s yours.

[meyer]

Lol - credit to you, KC. That is the perfect name for the newly-formed ravine - Moonbeam Canyon.

[meyer]

Outflow stopped for 4 hours to allow for surveying of the diversion pool...

http://www.actionnewsnow.com/story/35057508/oroville-lake-outflow-back-at-zero-again

[janetjanet998]

here is an update about the about of debris removed 2 hrs ago on their twitter page..but nothing about why they shut down the plant for 4-5 hours and why only back to to the lost 11,000 level

if it was something like you suggest one would think they would be talking about it

https://twitter.com/CA_DWR

[Jim W N]

Does anyone know of plans to lower the reservoir below where there is evidence of water seepage in the dam?

[Jim W N]

It will take that much to dig out Moombeam Canyon... LOL - Moonbeam Canyon! :)

That's funny. Definitely should be memorialized as "Moonbeam Canyon."

[Jim W N]

Ditto.

[Repeal The 17th]

A few new pictures are up ... 603 images now.
(shhhh - it’s a ‘secret’)
https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/Oroville-Spillway-Incident

[janetjanet998]

power plant output dropped to 10500 last hour

they can’t seem to keep it at maximum utilization

running 80% of what it was

[EarthResearcher333]

"Does anyone know of plans to lower the reservoir below where there is evidence of water seepage in the dam?"

That would be 660ft... I am unaware of any news or discussion about doing that. I do know that California water customers of Oroville are anxious if Oroville is going to meet all of their commitments in water shares. Farmers need answers now due to decisions of sowing crops (irrigation availability). DWR has yet to fully commit to water shares in the state. The SacBee article below discusses the belief by some that Oroville's reservoir will be kept lower to give a "safety buffer" on inflow when spillway fix work begins in earnest.

Why Oroville Dam’s woes could cut into California water supplies

[EarthResearcher333]

Oroville Earth Fill Dam Design - Drainage Zone (gravel cobble boulders) to collect seepage & Wet Area location

Blueprints reveal the compacted materials within the Oroville Earth fill dam, including a "Drainage Zone" filled with gravels, cobbles, and boulders to collect "seepage". The Drainage Zone is a 20' wide chimney constructed between the Transition Zone and the Pervious Embankment Shell Zone. Any seepage through the two Transition Zones and the center water barrier Impervious Zone is intended to be collected in the Drainage chimney. The Drainage Chimney has a 10' thick horizontal Drainage Zone that leads to a seepage monitoring station at the Toe of the dam. Below this side view blueprint image is the Feather River Embankment Canyon cross-section view. The "Wet Spot Area" is at an elevation that is near the seam abutment elevation of the Feather River Canyon walls. Grouting was performed along the canyon wall abutment. Note that the Palermo Outlet Tunnel is about 100 ft below the "wet spot area" in the canyon rock. If the Drainage Zone Chimney is ineffectual on this side of the canyon wall, then seepage could by bypassing the chimney (going horizontally through) and leveling out at the layer 2 to layer 3 construction boundary compaction seam.

There still is a correlation puzzle on reservoir water levels to the "wet spot" area (i.e. vegetation greenage in the Wet Spot area does not always correlate with reservoir water levels). Most notable was high reservoir water levels at the 2016 inspection date window of photos showing a dry zone & dead grass.

[Jim W N]

The idea, of course would be to keep it at 660ft long enough to repair the damage if the damage is reparable.

I mean with this leakage, is the dam reparable or is it a goner? What do you think the options are?

I mean if they don’t do something, it sure looks to me that at some point the water customers of Oroville are in danger of getting a lot more water shares than they bargained for.

[mad_as_he$$]

bttt.

Right now the next storm is forecast to dump hugh amounts of water in the region starting Thursday night.

[EarthResearcher333]

"I mean with this leakage, is the dam reparable or is it a goner? What do you think the options are?

Right now there is not enough data to infer the risk from this wet area. Earth Fill dams have a normal amount of seepage that is collected in the Drainage Zone chimney. The drawings show a seepage monitoring station at the end of the horizontal Drain Zone where seepage rates may be monitored for changes.

Personally, I don't think there is a structural risk to the dam at this moment. Why? the embankment erosion channels seemed to have developed over a number of years (image overlay & transparency shifting while examining any increases or changes to the erosion channels).

However, any wet area on the back side of the dam is very important to monitor & understand. This is exactly what the prior Dam Inspectors had put into their reports.

There is one avenue I'm still researching - that is, if there is a link to the Palermo Outlet Tunnel OR if there is a link to any type of hillside spring deep in the abutment. An "artificial spring" may be the source as the impervious core has a 50-75ft deep & wide "channel" cut into the hillside rock to act as a "keyed" anchor. If seepage is penetrating into the hillside rock from a grout missed fracture area, the hillside could act as a saturation holding tank (small but a form of a high elevation mini water table). When the reservoir water levels fluctuate below 660 ft, this may allow a backflow of this hillside mini-water table onto the horizontal seam layer 2 top and layer 3 bottom - causing the wet spot & greening to appear.

[KC Burke]

I think we should add for Jim and others with the same questions that there are repair techniques that are used when full understanding of an internal problem is reached. Short of cutting into a dam after reservoir draining, there are pressure grouting, relief drilling and other methods that are used when a problem occurs.

Diagnosis is paramount however as incorrect repairs could make matters much worse.

[Jim W N]

Thanks KC.

[EarthResearcher333]

"Diagnosis is paramount however as incorrect repairs could make matters much worse.

Yes, understanding the origin drives options.

I've read of techniques using sensitive InfraRed thermal imaging systems to help diagnose water seepage presence and sources. Subsurface percolation and evaporation provides a "cooling" thermal profile that would not be observable in the visible light spectrum. This has been used at dams to investigate wet areas deeper within the structure.

I've used FLIR systems to investigate warming spots on volcanoes. You need a thermal absorption profile of the rock to delineate/analyze the image results. An interesting note is that trees will absorb heat from the roots near the andesite and the full tree will appear brighter than the snow covered andesite areas with cooler trees.

[janetjanet998]

update

he took his own pics of the spillway today
https://www.youtube.com/watch?v=Mi9auu7muZY

[Repeal The 17th]

Good video.
At .55-it shows a lot of workers on the spillway and it looks like the shot-crete wall has held up.

Later on he talks about the “secrecy” issue.