Oroville — a small town — sits at the base of the nation’s tallest dam. Ironically, it carries the same name as the city. Last year a spillway disaster led to the forced evacuation of 188,000 people downstream from the dam. Among them are the citizens of Oroville.
To update you if you’ve forgotten, the dam’s operators — the State of California via the California Department of Water Resources (DWR) — noticed a crater-sized hole in the main spillway. They shut off the water flow to investigate. The dam filled up and water spilled over onto the emergency spillway which also deteriorated and that led to the crisis.
Citing a culture of cronyism and trying to maintain the dam as cheaply as possible, the city filed a lawsuit against the State of California for its damned dam failures. The suit said state officials did not deliver on promised benefits to the city and the skimping on repairs benefitted farmers and those in Southern California and not the people in Oroville.
While no dollar figure was mentioned in the suit, the city’s lead attorney Joseph Cotchett said the city’s damages are in the millions and he predicts other local governments, business owners and farmers and others will also file suit.
Cotchett added, “This was not an act of God. This was not just a wild rainstorm. This went back 20 years of neglect.”
The suit or soon to be suits — it turns out — is just the beginning of the Oroville Dam’s troubles. In line with Cotchett’s comment on years of neglect, a 584-page report by the independent forensics team hired by the Association of State Dam Safety and the United States Society on Dams concluded that no one factor contributed to the dam’s failure.
The report says it is just one in “long term systematic failure.”
It targets the DWR and is highly critical of its shoddy work. The report says at the time of the dam’s construction the DWR was “significantly overconfident and complacent about the integrity of its State Water Project civil infrastructure, including dams.”
The investigators found a report from October of 1966 saying the 3,000 foot spillway was being established on unstable ground and that it was being put on “very little solid rock.” The biggest criticism is the DWR — knowing the dam was going to be built on unstable ground — did it anyway. Lead investigator John France and his team said in 1948 when engineers were scouting dam locations, they pointed out that the rock around the dam was not suited for the project.
“The decisions were made with the best of intentions, but against the advice of civil engineering and geological personnel, who by then had recognized the poor bedrock conditions and the potential for unsatisfactory performance of the previously untested emergency spillway,” the report said.
The extra cost of $1.2 million to dig deeper and into more solid ground was what drove the decision to go ahead. Blame lies with then Governor Pat Brown — current governor Jerry Brown’s father — to get water south to San Diego as quickly as possible. Because of that the warning was ignored and as a result the dam has “a foundation that did not meet the original design intent.”
France told the Sacramento Bee, “That sort of set the physical stage for what happened 50 years later.”
Once the dam was finished in 1968, the DWR — France and his group said — forgot about the warnings and moved on. “Actual bedrock conditions, and the implications of those conditions, were well documented prior to and during construction, but there was no post-construction recognition of the weathering potential of the rock types present at Oroville. Detailed and accurate information was not properly accessed in subsequent years; rather, inaccurate and incomplete summaries of information were passed on through generations of DWR personnel,” the group concluded.
In the meantime, the DWR has finished the major repairs to the spillway. They were done in November but more repair work will be needed this summer. That means the costs will go way above the $640 million already spent.
Source links: Insurance Journal, The Weather Channel