See below:
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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.
Thank you for those pix of the “shift sensor” !
50 foot long section could break off & go downhill...
See below:
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so what exactly does this shift mean? If it shifted 1 inch at that location does that mean it has shifted more than 1 inch at the end of the spillway since its 50 feet away and at an angle?
lake at 860.6 feet down about a foot the past 24 hours inflows still 25,000 to 30,000
last 24 hour rainfall: .28 inches at the DAM and .75 to 1.25 inches in the mts the past 24 hours
todays rainfall: about 1/4 to 1/3 inch in the mts mostly this morning
next possible systems(will have up to date info later today):
Sunday: very light rain in the mts maybe .1 inch
Tuesday: a weak-moderate system similar to last nights
the lake needs to fall 23 more feet to get to 837 at 1.75 feet a day thats 13 more days so looks like the spill wil be around 19 days not 10-14 like DWR said
I have read these posts and may have missed it. There is one value you haven’t accounted for. The water which goes into the aqueduct.
That complex, along with other reservoirs in the system, can supply water to the river as needed for it’s normal needs and keep the aqueduct full and flowing.
The RIV REL value is how much is flowing in the river channel when all is said and done. BVB
Potential "Break Away". Movement detection of failing section of the damaged spillway. Emergency Repair Rock Bolts were not placed in this section (blue line downward). Rock Bolts placed in the next array of slabs above this "pulling away" seam. Thus the balance of the quality of rock + existing anchor rods determines how this section responds to spillway flow stresses (i.e. will it suddenly "fail"). This may be why the spillway is limited to 35,000 cfs.
I’ve seen a 2.5 foot long version of a big wide band-aid on a car. It was over a dent in the side of the car. Didn’t know if the person made it themselves or if it is something you could buy. Can you imagine the reaction if someone, as wry humor, stuck a bunch of these at various places on the spillway sidewall?
Considering that the slabs below the anchored area are partially damaged anyway, I don’t think they wanted to waste any money trying to save them. Besides, as you said, the rock beneath them is suspect (incompetent, or “ moonbeam” rock).
Do you think Bea is following this FR thread?
He admitted he got a lot of his stuff from Metabunk. They’ve got most everything we have here. I still lurk over there every once in a while, but I’ve quit posting, because the clowns who run the thing had gotten so anal retentive with their rules.
No speculation, they wrote. Hell, you can’t do investigative work without throwing ideas out for the group to debate. Brainstorming, I think it was called in college.
We know DWR is following Metabunk. Check out this post. One of Croyle’s people. Even misspelled his name to make it look good.
https://www.metabunk.org/oroville-dam-spillway-failure.t8381/page-41#post-204996
I for one wanted to note how lucky Oroville, DWR and everyone else was that they had Director Coyle on board that disastrous night. When the water started over the emergency spillway and the erosion was apparent immediately. It would have been massively stressful. Calling for the evacuation of town at the same time. Then someone has to throw out the idea, “we need to reopen the main spillway”.
It is clear now, in hindsight, when they reopened the main spillway they saved that structure and that town. I am sure in the heat of that moment, that was not so clear. They kept level heads, and managed with what data they had in hand. There was certainly a bit of luck that the remaining spillway structure and enough solid rock to handle the flows.
Every decision the response team has made sense, seems from what is available, to have been great decisions. Closing the Hyatt at the right times. Pushing massive debris removals. Anchoring and shotcrete on the remaining spillway. Armoring the emergency spillway. All seem, in hindsight, to have been done in the right order at the right times, to create more options as they went along.
I take a slight exception with the AP article’s headline
Content from external source
AP Exclusive: Managers made errors in handling of dam crisis
(link for reference: below). I do not think there was much wrong in the ‘handling’ of the crisis. I realize this is like editors/authors trying to come up with a sensationalized headline. Just feel it does not quite convey the correct sense.
Sure there was a lot wrong with the operations and maintenance of the structure that led to the crisis. That has been well documented, discussed here. The overall handling of the crises once the hole appeared in the deck, seems pretty good.
ref:
https://apnews.com/0a4b46c359444c58918ad374f7cd3d28
Maybe they are better at the pound of cure than the ounce of prevention...
Agreed WRT the rules. They seemingly don't like anybody outsid the "clique" to post.
bttt
DWR now says this current spill will last through the first week week of May(no surprise) also they are going to blast some of the cliffs.......
http://www.water.ca.gov/news/newsreleases/2017/042017_oroville_construction.pdf
The following activities, some already ongoing, are scheduled to begin April 21 through April 28.
DWR will provide regular updates on all activities over the coming months as construction
r
Slope setback with controlled blasting
• As part of regular procedure, DWR will use controlled blasting methods to break up intact
rock on the slopes along the damaged gated flood control spillway so that it can be safely
excavated. The slopes are near vertical and are up to 150 feet in height. These slopes
present a significant safety risk for construction workers.
• The controlled blasting produces little to no audible noise or vibrations. A whistle/air horn
will alert workers near the project area prior to each controlled blast.
• Seismographs will be located throughout the project area so engineers can monitor
movements and to make sure recorded vibrations are within safe levels.
• The controlled blasting will begin as early as Friday, April 21, and will continue for four to
six weeks on approximately an every-other-day schedule, so that workers can start
making necessary repairs to the spillway to meet the tight construction schedule.
• DWR obtained required permits for the work from its state and federal regulatory
partners, as well as the Butte County Sheriff’s Department.
Gated flood control spillway flow release update
• The damaged gated flood control spillway also known as the main spillway, is currently
spilling 35,000 cubic feet of water per second. Based on current hydrologic modeling, the
spillway will continue at this flow through the first week in May
New Federal Energy Regulatory Commission filing documents detailing issues pertinent to the current Oroville Repair/Recovery Crisis. These documents detail the conflicting statements by DWR & the CA Division of Safety of Dams (DSOD) with the actual dangerous erosion of the Emergency Spillway. DWR & DSOD stated that the hillside was adequate - proven significantly incorrect. These documents filed to FERC also identify the concerns of secrecy in the new construction repair/recovery process - that it is inadequate for concerned citizens (public) to have proper access & review. Notes that the volume of rock in the large area of the spillway should not be hidden as secret via CEII, in addition to noting that such rock would be of little interest to "an attack".
Documents reveal the significance of the 1960's political engineering decision to create a separate Emergency Spillway instead of working out the kinks in getting a fully armored "Combined & Delta Main + Emergency Spillway design" perfected. By DWR making this "engineering" switch to an Emergency Spillway that was "deemed" to be very rare in its use, this decision has come back to haunt the dam design. This decision created the dangerous problem of the loss of a "safe redundant" spillway in case the main spillway had a breakdown. All for the sake of "deeming" the Emergency Spillway would likely not be used except in very rare circumstances - in that the Probable Maximum Flood (PMF) would be so rare that the use of the Emergency Spillway would be 10,000 years or greater. What was not included in this decision was a failure of the main spillway. The Emergency Spillway needs to be a "safe backup" or "redundancy" to cover this contingency.
These documents re-inforce the engineering culture pitfalls of the "politics of engineering" decisions that must not occur in exceptionally critical infrastructure. These documents also demonstrate the continued defense by DWR & DSOD of the 1960's decision in stating the Emergency Hillside was adequate for use. Thus the reinforcement of the poor engineering competency is again revealed in the "loss of safe redundancy" by the first go-around in defending against armoring the hillside in a prior FERC filing & review. Now, today, we have DWR & DSOD complicit in poor engineering competency in revealing yet again a non-safe redundant emergency spillway. This design will not safely operate 369,000 cfs, (a required spill rate spec by the Board Of Consultants), as the apron does not protect the full hillside down to the Feather River.
How many times will this poor engineering competency set of "reasoned away" PMF excuses be used? Yet, the real use of the ES has been for "safe redundancy" - of which it failed spectacularly & will so in the future as the new concept design stands.
note: Blue & red underlining markups, arrows, & comments added for discussion notation - not part of the original document.
Image 1: Newly Filed FERC Submittal of doc 20170419-5231 - Request of Friends of the River, CSPA, American Whitewater, SYRCL, and Sierra Club for clarification of licensing/dam-safety proceedings/process and for a public process at Project 2100 reconstruction.
Image 2: Newly Filed FERC Submittal of doc 20170419-5231 - Request of Friends of the River, CSPA, American Whitewater, SYRCL, and Sierra Club for clarification of licensing/dam-safety proceedings/process and for a public process at Project 2100 reconstruction.
Image 3: Newly Filed FERC Submittal of doc 20170419-5231 - Request of Friends of the River, CSPA, American Whitewater, SYRCL, and Sierra Club for clarification of licensing/dam-safety proceedings/process and for a public process at Project 2100 reconstruction.
Image 4: Newly Filed FERC Submittal of doc 20170419-5231 - Request of Friends of the River, CSPA, American Whitewater, SYRCL, and Sierra Club for clarification of licensing/dam-safety proceedings/process and for a public process at Project 2100 reconstruction.
check out these two points....
• The controlled blasting produces little to no audible noise or vibrations.
• Seismographs will be located throughout the project area so engineers can monitor
movements and to make sure recorded vibrations are within safe levels.
so which is it? No vibrations or enough vibration they have to place equipment to monitor them to make sure the vibrations are not too strong?
The US Bureau of Reclamation distinguishes three classes of spillway. Friends of the River et al., refer to the Oroville spillway as an auxiliary spillway, the design docs call it an emergency spillway.
3.1.1 Spillways
[] There are three classifications of spillways typically employed by Reclamation, which are based on frequency of use. They are explained in more detail in the following sections.
3.2.1.1 Service Spillway
A service spillway provides continuous, or frequent regulated, or staged releases5 (controlled) or unregulated (uncontrolled) releases from a reservoir without significant damage to the dam, dike, or appurtenant structures due to releases up to and including the maximum design discharge. Service spillways are typically very robust, erosion-resistant structures consisting of mostly cast-in-place reinforced concrete and riprap channel protection. Some examples of service spillways are illustrated in figure 3.2.1.1-1.
3.2.1.2 Auxiliary Spillway
An auxiliary spillway is infrequently used and may be a secondary spillway (augmenting a service spillway discharge capacity). During operation there could be some degree of structural damage or erosion to the auxiliary spillway due to releases up to and including the maximum design discharge. Auxiliary spillways may be less robust, erosion-resistant structures consisting of some cast-in-place reinforced concrete, riprap channel protection and/or unarmored excavated channels. Some examples of auxiliary spillways are illustrated in figure 3.2.1.2-1.
3.2.1.3 Emergency Spillway
An emergency spillway is designed to provide additional protection against overtopping of a dam and/or dike and is intended for use under unusual or extreme conditions such as misoperation or malfunction of the service spillway or outlet works during very large, remote floods (such as the PMF), or other emergency conditions. As with auxiliary spillways, some degree of structural damage and/or erosion may be expected due to releases up to and including the maximum design discharge. Emergency spillways are the least robust, erosion-resistant structures consisting of some cast-in-place reinforced concrete, riprap channel protection, and/or unarmored excavated channels. Some examples of service spillways are illustrated in figure 3.2.1.3-1.
see generally https://www.usbr.gov/tsc/techreferences/designstandards-datacollectionguides/designstandards.html#final
I think it would be wise for a dam this large to have an auxiliary spillway in addition to an emergency spillway.
It’s common practice to use seismographs to record the acceleration “shock” waveform data for the purposes of demonstrating that their actions did not cause any damage to nearby structures. View it as a liability backup of proof to show that they didn’t cause someone’s house foundation to crack - in case it is claimed.
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