Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
The guy on the live news feed says "about this far" (gesturing about four inches). That's assuming the hole that's forming hasn't worn through to the other side.
So stumps ramming fishing piers was more... I’m not really understanding this very well. Our dam operations here (7 dams on the 8 Highland Lakes, 2 Hydro) are extremely complicated... this dam just, something weird is going on.
“Another data point just came in. The lake level has dropped 1/2 foot in the last two hours.”
Area of Lake Oroville is about 65,000,000 square meters. It dropped about .07 meters/hr. That’s about 4,550,000 cubic meters/hour, or about 1,201,655,000 gallons/hr, or about 20,000,000 gal/min (2.67 million cubic feet/min), or only 45,000 cf/s.
Since I heard they are releasing 100,000 cf/s, unless there is a lot more water coming into the lake, they should be OK after several more hours.
The emergency spillway is concrete with piers. The concern is at the northwest end where the substrate is just dirt and stone, basically ordinary ground, at the corner of the parking lot.
Poor design and poor maintenance.
Everybody knows that you can’t have flowing water on an earthen dam. The emergency dam to the left of the spillway is concrete atop a earthen dam. Water is overtopping the emergency dam and eroding the earthen base.
The emergency concrete spillway was damaged and never repaired.
Remember a dam a few years back. The erosion from the overflow eventually ate away under the dam so the lake behind drained like a bath tub. It was small but even that small was horrible for those down stream.
Good math work! Inflow’s about 40K cfs at the moment.
That's the main spillway. And that hole is kind of "cosmetic", to tell you the truth, it just goes down to bedrock and that's the end of it. It is eroding to the sides which is kind of messy. But the hole is nowhere near the lake -- it is far back through the hill.
V notch effect & dam construction post by an engineer
https://www.linkedin.com/pulse/oroville-dam-failure-scott-cahill
Evacuation orders are “just in case”.
That’s what I’m starting to wonder.. is this a planned failure?
Either A) the engineers, at design, never dreamed there could be rainfall like there has been recently (unlikely), B) Engineers assigned to the dam are crooked and not reporting decay - and where is ACE on this?! - or C) somebody wanted that dam to fail.
Never attribute to stupidity that which is explainable by malice.
The big hole part way down the main spillway has nothing to do with the dam’s ability to hold the lake back.
I was born and raised in LIve Oak, survived the flood of Christmas 1955. Oroville Dam was planned and built due to that devasting flood. Yuba City was hit the worst during that one. Prayers for anyone living south of the dam
Jerry Brown’s merry band of bureaucrats have been in charge too long. CA has had several periods much above average rainfall since 1968, not a problem before. DWR waited too long looking at the “hole” in the regular spillway...should have been releasing at 50,000+ CFS all along and fix the spillway later. Now they are behind the curve and doing 133000+ CFS to try and prevent water from going around the end of the emergency spillway.
Lake level is down about a foot since 8am:
http://cdec.water.ca.gov/cgi-progs/queryF?s=ORO&d=12-Feb-2017+19:43&span=12hours
KCRA talking heads are starting to make relief noises re the water level at the emerg spillway currently dropping slightly, as the main spillway has been opened to 130,000cfs.
However, any significant undercutting/holes that might already have developed on the lee side would throw the engineering parameters into some question/doubt for the structure as a whole.
With even more storms forecast for that area early in the week, the situation seems by no means resolved, even should tonight pass without a major breach.
Anyway, apologies for the naysaying, FRiend.
There was a thread a few months back about a dam in Iran looking like it was going to fail.
did that thing ever go down?
We have three more dry days, then 8 more days of rain. Real disaster, but not to worry we will protect the illegal felons.
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