Dozens of California dams need repair as El Niño winter draws closer

With an El Niño winter threatening heavy rain, the State Auditor warns that California’s aging dams “continue to pose a risk to public safety,” especially in the Bay Area, San Diego, and Los Angeles areas.

Lawmakers gave the state the power to penalize dam owners that violate safety requirements in 2017, after the Oroville spillway failure forced the evacuation of nearly 200,000 people. Water managers have yet to use that power, the audit found.

Even if state water managers had wielded their enforcement powers, dam owners likely couldn’t have afforded the fixes.

An audit released Monday found 57 dams in poor or unsatisfactory condition as of May, up from previous counts. That number is likely to keep rising, as state water officials reevaluate aging dams.

The 40 riskiest dams — rated high or extremely high hazard — are located throughout the state, but cluster near densely populated coastal cities.

Should these dams fail, the auditor reported, “they could collectively endanger as many as 1.5 million people and cause more than $265 billion in economic damage.”

Almost a decade ago, lawmakers strengthened the California Department of Water Resources’ authority to impose penalties such as reservoir restrictions, property liens, and fines when dam owners violate state safety laws and other requirements.

State engineers have referred owners of 44 dams for enforcement as of April. But, the auditor wrote, the water resources department “has never taken punitive enforcement actions against dam owners that fail to remedy their violations.”

Aging dams, limited funds

The problem is that dams are getting older. Many were built when safety standards were softer. State laws never required dam owners to set aside funds to keep them safe, so when concrete crumbles, sediment accumulates and spillways threaten to erode under floodwaters, most dam owners lack the money for repairs.

The state’s water resources department oversees the safety of more than 1,220 dams, most of them in satisfactory condition. Responsibility for maintaining the dams falls to the local governments, utilities, water agencies, and the private landowners and companies that own them. Some of the dams rated in poor condition are owned by state agencies.

Disasters are extremely rare. But when they do occur, like in Oroville, or the 1928 collapse of nearly-new St. Francis dam northwest of Los Angeles — they can be catastrophic.

San Diego’s Lake Hodges Dam under repair in fall of 2022. The dam is expected to be replaced in the next decade. The dam, built as a multiple arch design, was completed in 1918, and purchased by the City of San Diego in 1925.

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Photo courtesy of John Gastaldo

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The auditor applauded the water resources department’s inspection program but blasted its failure to enforce against dam owners who fail to meet state planning, safety or other requirements, “thereby allowing serious deficiencies to persist.”

One of the cases involved a dam with a 47-foot-wide hole in its spillway that has gone unrepaired for more than 30 years, which the audit said could cause flooding affecting nearly 300 people and more than $88 million in damage.

The audit doesn’t name the dam. State water managers said more specifics could pose security concerns, though the department makes each dam’s hazard potential and condition public in an annual report.

State water managers finalized the enforcement regulations in 2022. But they told the auditor they haven’t been able to adequately staff an enforcement branch and aren’t confident they could afford to defend their actions in a hearing.

Even with staff and money, the auditor concludes, if a dam owner remained noncompliant, the state “cannot act before the dam poses emergency-level danger. This leaves a gap in state law that puts public safety at risk.”

Drop in the bucket

Gov. Gavin Newsom touted dam repairs in his drought-era water supply strategy four years ago, as a way to shore up water supplies. Two years later, in 2024, Newsom and lawmakers slashed funding for a dam repair grant program.

Since then, a 2024 ballot proposition delivered a $464 million infusion for the program. A Federal Emergency Management Agency grant also awarded California $629,198 this September, according to Jason Ince, a spokesperson for the Department of Water Resources

But the audit cited estimates that repairing the state’s less-than-satisfactory dams could cost around $28 billion, making the funding a drop in the bucket.

The report urged state lawmakers to set deadlines and require dam owners with high and extremely high hazard dams — meaning ones that could kill people if they fail — to submit maintenance and repair plans to state agencies.

It also called for lawmakers to expand state water managers’ enforcement authority, and for the agency to use the full force of its powers.

“To ensure that the safety of the public is addressed before a dam’s condition results in an emergency,” the audit said, “the Legislature should amend state law to allow Water Resources to order the condemnation and decommissioning of a dam when Water Resources’ other means of enforcement are unsuccessful.”

Laura Hollender, deputy director of flood management and safety with the Department of Water Resources said that the department worked closely with the State Auditor but disagrees with some of the report’s findings and recommendations.

Still, she said in a statement, they are carefully reviewing the recommendations and preparing for whatever El Niño brings. “Protecting public safety is DWR’s highest priority, and we recognize the critical role that dam safety and levee maintenance play in reducing flood risk for California communities.”

As the wet season approaches, the auditor also highlighted that dam safety planning statewide is incomplete.

The Governor’s Office of Emergency Service has not yet approved emergency plans for 245 dams describing what their owners would do to protect people and property should the dam fail. Officials told the auditor’s office that dam owners haven’t completed required revisions, and state law doesn’t require deadlines. 

This article was originally published on CalMatters and was republished under the Creative Commons Attribution-NonCommercial-NoDerivatives license.