Dams’ owners allow problems to linger
SACRAMENTO » The owners of some of California’s most critical dams have allowed problems identified in annual inspection reports to linger for years, a newspaper reported Friday.
Unrepaired deficiencies include cracked concrete, rusted equipment, broken sensors, and frozen valves and gates, according to a Sacramento Bee investigation.
State officials said the problems are not imminent safety threats. And dam owners said it’s best to methodically research problems and design repairs if there’s no emergency.
But experts said seemingly small problems can add up and eventually cause a crisis.
Outside investigators looking into the cause of a catastrophic crater in the spillway at Oroville Dam this year say a drainage system clogged by tree roots likely contributed.
The problem set off a cascading series of events that eventually led to the evacuation of nearly 200,000 people amid fears that uncontrolled flooding would swamp communities downstream, though the crisis was averted.
The newspaper published its report the same week residents near Oroville Dam told state water officials that they can’t be trusted when they say small cracks in the
rebuilt Oroville spillway are not a safety risk.
The repeat offenses show the state has to do a better job of cracking down on dam owners whose facilities don’t measure up, experts said.
“You’ve obviously got an enforcement problem,” said J. David Rogers, a damsafety expert at Missouri University of Science and Technology. “The inspections are taking place, but the mitigation measures, the upkeep and maintenance — there must not be a very severe penalty for not doing the things . ... There’s got to be teeth in the system.”
The newspaper looked at five years of inspection reports from 93 dams where state officials ordered a comprehensive review of spillways after the Oroville incident.
Ninety-one are considered “high hazard” facilities, meaning a failure could kill people downstream. Every inspection report reviewed by The Bee pronounced the dams “safe for continued use,” even
if the same shortcomings were cited year after year.
The state’s Division of Safety of Dams has jurisdiction over 1,249 facilities but does not inspect federal dams, including Shasta and Folsom dams. Federal inspectors are conducting their own reviews of dams they oversee following the Oroville scare.
“Issues that do not present an immediate dam safety concern, and are related to routine maintenance, are given lower priority and may appear in subsequent inspection reports,” said Erin Mellon, a
spokeswoman for the Department of Water Resources, which oversees the dam safety division.
The Bee’s review of inspection reports was obtained through the California Public Records Act.
It found some problems went unaddressed for years. They ranged in scope from multimillion-dollar repairs to small jobs that could have been performed quickly by workers with hand tools.
“Patching a spillway is not like patching a sidewalk in front of your house,” said Mark Hutchinson, deputy public works director in San
Luis Obispo County, where it took four years for officials to pinpoint and fix the cause of a small leak near Lopez Dam. The project required remote cameras and specialized concrete mixes.
The documents could contain evidence of even more serious problems that were impossible to determine because the state blacked out large portions of inspectors’ findings, citing terrorist concerns, before giving them to The Sacramento Bee.