Commentary: Forensic report confirms Oroville Dam lapses

The verdict is in and California stands convicted of gross negligence in the construction and maintenance of the nation’s highest dam, Oroville.

The dam on the Feather River came very close to failing last year, forcing the evacuation of a quarter-million people living downstream. Heavy outflows revealed structural flaws in the dam’s concrete spillway and when dam operators switched to an auxiliary spillway that dumped water onto an “unarmored” earthen hillside, it quickly eroded, threatening the entire structure with collapse.

Officials blamed the near-failure on heavy winter rains – and used that rationale to seek disaster aid from the federal government – but had the spillway been designed, constructed and maintained properly, and had the auxiliary spillway been upgraded as critics had urged, the heavy flows would have been handled easily.

Outside experts said as much in their critiques and the federal government’s 584-page report, released this month, essentially confirms that stark appraisal.

“The Oroville Dam spillway incident was caused by a long-term systemic failure of the California Department of Water Resources (DWR) regulatory, and general industry practices to recognize and address inherent spillway design and construction weaknesses, poor bedrock quality, and deteriorated spillway chute conditions,” the first page of the forensic report declares. “The incident cannot reasonably be ‘blamed’ mainly on any one individual, group, or organization.”

Oroville’s dam and reservoir, with a capacity of 3.5 million acre-feet of water, are the star features of the California Water Project, which supplies water to Silicon Valley and via the California Aqueduct to San Joaquin Valley farmers and millions of customers in Southern California.

Built in the 1960s, it is also the hallmark achievement of the late Gov. Pat Brown, father of the state’s current governor, Jerry Brown.

With the forensic team’s report, however, it’s evident that as important as it has been to the state’s growth and economic prosperity, the dam was not built correctly. Among other things, the report points out that the dam’s main and auxiliary spillways were designed by an inexperienced engineer and when the flaws became apparent, they were inadequately repaired.

The flaws “were quickly deemed to be ‘normal’ and as simply requiring on-going repairs,” the report states. “However, repeated repairs were ineffective and possibly detrimental.”

Clearly, for decades there was no willingness at DWR to acknowledge the fundamental nature of the flaws and spend money to repair them.

That would have required bureaucrats and their political overseers to admit error and tap water agency clients for the money to make the fixes.

What was done, or not done, eventually resulted in near-disaster. Oroville reinforces why we should be skeptical when officialdom says it knows what it is doing, and a cautionary tale about other major public works projects.

A few years ago, when the Sacramento Bee punched through a cloak of secrecy and revealed flaws in the reconstruction of the eastern third of the earthquake-damaged Bay Bridge, Jerry Brown dismissed it as “shit happens.”

As mayor of Oakland when the bridge project was being considered, he insisted on the futuristic design that led to its costs quadrupling and construction defects. He’s also been silent on the Oroville situation other than to praise DWR for handling the dam’s near-failure adroitly.

Brown, however, is advocating two other immense projects, twin tunnels beneath the Sacramento-San Joaquin Delta that would complete his father’s water plan and a north-south bullet train that he first proposed during his first governorship four decades ago.

Brown insists that both are needed and the state has the financial, managerial and technical capacity to build them.

That’s what his father said about Oroville.