When the Oroville Dam failed earlier this year, it prompted a review of numerous major infrastructure projects throughout California. The news is not good, as it is clear that many billions of dollars of tax-funded projects were designed and constructed to withstand significant seismic events. That’s because we’ve learned that our previous codes and standards were too lax.
A preliminary report reviewing the failure of the Oroville site specifically shows that even the less stringent codes and standards or yesteryear were not adhered to. According to Steve Schooner of the Chico Enterprise-Record:
The result was a spillway as thin as 7 inches in places, much of it built on rock that was not sound enough for anchors driven into it to hold the concrete slabs in place.
The concrete was prone to crack in the thin spots, letting more water though the concrete than the drainage system was built to handle. The drainage system was designed just to carry away groundwater seepage, according to John France, leader of the forensic team, who spoke to reporters during a conference call Tuesday afternoon.
Repairs were also faulted as “generally limited in extent, rather than designed to reliably and durably withstand high-velocity flows.”
The truly scary part: Oroville’s situation is far from resolved, and (based on inside information I have access to) there isn’t a ton of confidence that the fix proposed will adequately address the issues.