Urgent Oroville Dam Update – Collapse Risk High
From: [Name Withheld]
Date: 25 September 2017 at 4:34:21 pm AEST
To: William Costellia
Subject: >>> Urgent Dam Update2: Collapse Risk At Oroville Dam – Unacceptably High <<
Please convey this important message to God’s Children living in California USA and especially for those living near Oroville Dam.
The California Department of Water Resources (DWR), the owner/operators of Oroville Dam, released the anticipated Dam Leakage report in late August. This report is the one that I was concerned could confuse the public into complacency regarding a sudden dam breach risk. This report is deficient with respect to a proper comprehensive engineering analysis of the Dam Leakage that includes a selective exclusion of critical evidence. This analysis methodology and misinterpretation of evidence leads to critical errors, in their report summary claims, in that “there is no threat to the safety of the Dam”. See below for details.
Early snow and hail have occurred in the Sierra Nevada Mountains on the last day of this summer. Oroville Dam was built to capture the runoff from these mountains. We may be facing an early rainy season. With these current developments, and with the unacceptable dam breach risk (too many unknowns and strong through the dam leakage evidence), prayers are needed to alert God’s Children that may be in harm’s way if the Dam were to suddenly escalate to a Breach Failure.
A history of inadequate engineering analysis by DWR – Two Spectacular Failures
A history of inadequate engineering analysis by DWR has revealed to the public the degree of these consequences from two spectacular failures at Oroville Dam. Because of these deeply flawed analyses, it resulted in the immediate evacuation of 188,000+ people, with less than an hour’s warning to a “failure”, with a possible 30 foot high wall of water racing down into the nearby towns. Panic spread as the escape roads were clogged from vehicles with residents fearing for their lives.
This first engineering analysis failure stemmed from DWR’s claim that the Emergency Spillway was on “solid bedrock” and there was no risk. Yet their analyses were severely flawed, and proven incorrect, as the Emergency Spillway failed at only 3% of its rated capacity. The cause was found from an improper analysis of the erosion characteristics of “highly weathered fractured rock” – called rotten rock, not solid bedrock. The Emergency Spillway hillside had widespread and deep layer of highly erodible “rotten rock”, not “solid bedrock” as they had claimed.
The second engineering analysis failure led to the blowout destruction of the massive concrete Main Spillway. DWR claimed the Main Concrete Spillway was constructed and anchored upon “Extremely Competent Rock”. It was not. Their own historical Geological and Construction engineering reports revealed the Main Spillway was constructed upon large and deep clay seams, not solid bedrock. The Main Spillway experienced a “blowout failure” with extreme hydraulic pressures developing underneath the concrete slabs.
The failed Main Spillway had to continue to be operated with high water flows to keep the failing Emergency Spillway hillside from triggering a “toppling” of the tall concrete Emergency Spillway Weirs. The Main Spillway Failed at only 18% of its rated capacity.
New inadequate engineering analysis – Leading to a Sudden Dam Failure? – a Third Spectacular Failure?
DWR has chosen again to selectively present information dismissing a potential dangerous leak in the dam to be “only from rainfall”. Again, their analysis is deficient regarding a comprehensive investigation to accurately establish that there is no risk from a dangerous leak within the dam.
DWR does admit there is a process of “suffusion” occurring on the backside of the dam in large “Erosion Channels”. Yet they fail to test or measure how deep this suffusion of fine materials goes into the embankment. Without this knowledge of the extent of the deep migration of sands and fine materials in the mix of the boulders, rocks, and cobbles, the stability of the dam may be structurally compromised. There are many more other engineering evidence examples that have been dismissed in DWR’s analysis – that was given to the public in their recent report on the Dam.
A comprehensive rebuttal 129 page report was created by concerned engineers and scientists regarding the dangerous oversight DWR’s recent Dam report analysis. I have studied this extensive report and I fully agree with the findings. This full report has not been released to the public, however I have permission to share a “Summary section” of this report below. There are other important references, articles, and interviews below that further detail this risk to Oroville Dam.
Will the Public get any Warning to a Sudden 770 ft tall Dam Failure?
The lack of any warning to the hundreds of thousands of residents from a 770 foot tall Dam Breach Failure is of the greatest concern. A faulty engineering analysis will lead engineers – and the public – to believe that there is no risk of a sudden dam failure. DWR is under extreme public pressure from the two prior Spillway Failures. Currently, DWR is facing a class action lawsuit with claims of nearly $1.6 Billion Dollars from the consequences of these two failures in flood releases, evacuations, property value losses, lost business revenue, and farmland destruction. Given this history, and the history of DWR’s exhibited priority of “Public Relations Image” concerns, engineers would be extremely hesitant in issuing a warning if an outside embankment surface leak were to suddenly develop. It was by God’s Providence that Law Enforcement (Sheriff) discovered the imminent Emergency Spillway failure threat. The Sheriff called an emergency meeting with DWR officials and swiftly drove the decision to notify the public to evacuate. It was by a sheer accident that the Sheriff discovered the Emergency Spillway Failure danger as he overheard a comment from a DWR engineer. The Sheriff was not notified by DWR of the immediate failure danger as he was originally heading out of DWR’s offices.
However, a Dam Breach Failure would escalate quickly to where there would be little to no time to investigate. Any delays of indecision by DWR engineers, directors, and public relations – since they fully believe that there shouldn’t be a leak through the dam – could cost tens of thousands of lives or more. The Breach Failure and collapse of the 1976 Teton Dam in Idaho and the 1928 St. Francis Dam in California starkly demonstrate this where there was little time left to investigate before their sudden collapse.
With God’s Providence again, it may be through social media, private citizens, a conscientious engineer, and possibly a Sheriff being in the right place at the right time, in discovering and revealing the early warning leakage, which may be the only warning the citizens may receive.
Scott Cahill: Collapse Risk At The Oroville Dam Is Still Unacceptably High
“Oroville Dam could end up in the history archives as the greatest natural disaster in California history, if not in the entire United States, if it is later found to be from a destabilizing internal leakage that led to a sudden breach of the dam,” they wrote.
Oroville Mercury Register, Risa Johnson, Sept 6, 2017
Urgent Oroville Dam Update – Prayers Needed, July 30, 2017
“Ominous news of a “breach danger” within the U.S.A.’s tallest earthen dam, Oroville dam, has been revealed by a team of independent scientists and engineers in a newly released report (see news articles below).
I can attest to the specific scientific and engineering information that reveals this serious danger. Nearly 200,000+ nearby residents risk a massive flooding catastrophe if the internal defects in the leaking dam were to escalate, possibly with not much warning.
Instead of responding with the care of love of brother and sister, in the responsibility to keep safe from harm, the State Department of Water Resources, who operate the dam, are ignoring the mounds of evidence in this report.
There are some caring souls within the organization that do desire to help, and have helped quietly from within, but they are being over-ruled by leaders who care more about looking good in public relations than admitting that there are serious design risks.”
OROVILLE DAM FAILURE? — September 5, 2017
(Special Permission to release – “Summary section” of New Sept 5, 2017 report. 129 page Report that contains extensive data & analyses from scientists & engineers tied to UC Berkeley Risk Management group headed by Professor Robert Bea)
REPEAT OF ST FRANCIS DAM AND TETON DAM FAILURES?
Appendix A reveals that DWR* faces crucial uncertainties, conflicts in analyses, and an extensive lack of consideration of critical relevant factors, in the current seepage report (presented as “rainfall only”) regarding an accurate determination to the source to the Dam Green Wet Area. Appendix A details the history, the extent, and relevance of these numerous critical issues that should have been fully analyzed and thoroughly investigated regarding the Green Wet Spot Seepage Anomaly. This compilation includes DWR’s consideration, but then dismissal, of an Oroville Dam Failure condition leading to a potential major Dam seepage related failure (item 31).
The described Oroville Dam failure sequence is near identical to the abutment seepage and the subsequent swift and catastrophic breach failure of Idaho’s Teton Dam in 1976. Yet, between DSOD** and DWR there have described and noted four different versions of the “source” of the seepage, each of which conflicts in evidence between the versions with respect to each other. With “versions” ranging from DWR noting to FERC in a 2014 Part 12D detailed analysis that the “seepage source” is from a “plurality of an existence of natural springs”, to a singular “a natural spring” in an April 2017 town hall meeting, then to DWR changing to a narrative of “rainfall only” in their newly released report. Conspicuously missing in the new DWR report are DSOD inspection reports detailing strong evidence of a “through the dam leakage” path, in defining the “reservoir” as the seepage source (2014 and 2015 inspections). Most notably, the DSOD July 2015 inspection report found wet seepage on the face of the dam even in a severe heat and an on-going drought which included photographs of brown grass. Thus any narrative of a “nothing to worry about” emphasis in placing the seepage source as “rainfall only”, with so many unanswered questions, may result in a dangerous complacency.
The Left Abutment has proven to have numerous cracks, in the metavolcanic rock, that surprised DWR in its stability behavior by the large 100,000 cubic yard rockslide during construction; even after the rock excavation was “thought to be” completed. DWR blamed the destabilization from heavy water penetration into “cracks” in the rock that triggered the massive landslide. This same nature of a geological surprise, in unexpected geological abutment conditions, was a primary root cause to the failure of St Francis Dam in 1928. Yet, with no working piezometers in the dam, DWR is heavily placing the measured safety of the dam using simple peripheral seepage points as “indicators” from the toe drain, gallery tunnels, and core block seepage. Thus, any “lost” or “unseen” water penetration, that escapes these “indicators”, could go unnoticed until the potential event of a sudden breach failure occurs.
Indeed, a DSOD inspection report notes a volume of water penetration, increasing every year, through deep rock cracks in the Left Dam Abutment into the Hyatt Power plant. This clearly demonstrates the ability for water to migrate deep into the Left Abutment rock through cracks. This level of high “transmissivity” in the Left Abutment Rock has the ability to divert internal “unseen leakages” away from the toe drain seepage weir. With DWR critically depending only on these “indicators”, without any internal piezometers or sensors providing “definitive proof”, DWR is making a High Risk choice that has a “catastrophic High Risk potential” that was well described in their Part 12D Dam Failure exercise in 2014. This was dismissed by DWR as their version was from a different core leakage mechanism (DWR had not considered Left Abutment slope induced failure mode of “Differential Settlement” in the Part 12D analysis exercise). Until DWR answers all of the crucial relevant factors, with a thorough investigation and using “in the dam” piezometer instrumentation giving solid “proof” data, Oroville Dam could end up in the history archives as the greatest natural disaster in California History – if not in the entire United States – if it is later found to be from a destabilizing internal leakage that led to a sudden breach of the Dam.
*DWR – California Department of Water Resources
**DSOD – California Division of Safety of Dams