Why this Placer County dam keeps getting cited in inspection reports
Cracked concrete. Plugged drains. Unchecked tree and brush growth. Broken outlet valves.
These are some of the problems that have gone uncorrected for years at California dams in spite of being flagged repeatedly by inspectors from the state Department of Water Resources. The sample below is based on a Sacramento Bee analysis of five years of inspection reports at the 93 dams singled out for further review by state officials following the February crisis at Oroville Dam. All of the dams mentioned below are classified as “high hazard” by the state because of their proximity to people living downstream.
Nobody home at North Fork
The inspector who showed up in September 2012 at tiny North Fork Dam, owned by the Pacheco Pass Water District in Santa Clara County, could barely hide his frustration.
“None of the requested work from (the) last inspection has been performed at the dam,” he wrote. “Work involved removal of vegetation from the dam and the spillway. I again requested the owner remove all the brush from the downstream and upstream face of the dam and from the left spillway wall. The owner assured me this work will be done.”
The shortcomings piled up, year after year. In 2014 an inspector said cracking had left the spillway’s concrete surface in “poor to serviceable condition.”
At an August 2016 inspection, inspectors got to the root of the problem: “The Pacheco Pass Water District...does not have a functioning board of directors and measures have been taken to dissolve the District,” an inspector wrote.
That appears to be changing. After a decade of inactivity, a new board was elected last December. Rob Bernosky, board secretary, said the flaws cited repeatedly by the inspectors aren’t “terribly egregious” but are being addressed. Pacheco Pass is also evaluating its long-term future, holding talks with the much larger Santa Clara Valley Water District about a possible takeover.
A frozen valve, and a $30 million headache
As state inspectors watched, employees struggled to open one of the outlet valves of Newell Dam, 11 miles north of Santa Cruz. It’s a task that’s supposed to be performed once every three years in the presence of inspectors, to show the valves are in good working order.
The Aug. 23, 2012, demonstration didn’t go so well. One of the valves opened, but stayed frozen “in the half-open position,” the inspectors wrote.
It’s still stuck.
Eileen Cross, a spokeswoman for the city’s water department, said Santa Cruz developed an “acceptable workaround” that got the state’s approval while the city figured out how to pay for the project.
“It’s like a $30 million project,” Cross said. “For us it’s a huge, huge project.” Repairs are getting underway soon, she said.
‘Uncontrolled release of the reservoir’ – or not
Lake Curry, located in Napa County and owned by the city of Vallejo, has been a trouble spot for decades. Since 1995 the state has reduced the maximum of water the reservoir can store, by about 8 percent, because of various deficiencies.
For the past three years, the state has focused on a corroded cast-iron pipe through which water is released from the lake.
Inspectors in 2014 said the pipe “varies from fair to poor condition,” and a failure could result “in uncontrolled release of the reservoir.” After a 2016 inspection, they again warned about the pipe’s deterioration.
City officials told the inspectors they were waiting on funding for repairs, and in June 2016 they submitted a plan to fix the problem. Michael Malone, director of Vallejo’s water department, said the work should be completed soon. He added that, despite the inspectors’ warnings, the city’s consultant concluded that the problem wasn’t a serious safety concern after all.
“The public is not in danger,” he said.
Getting the valves to work
Every three years, dam owners must demonstrate that their valves and gates can open and shut properly.
When inspectors showed up in September 2014 at Rollins Dam, in the Nevada County foothills, expecting to get a demonstration, an “electric systems malfunction” kept the valves from operating.
During a follow-up inspection three months later, one valve opened perfectly but the other got stuck after opening two-thirds of the way. A 2015 inspection report said the valve could open 88 percent, after hardened grease had been removed from the mechanism.
In September 2016 the Nevada Irrigation District told inspectors they were designing replacement parts for the valve, which “still cannot be fully operated,” according to the state’s report. Installation was expected to be completed last month. District officials didn’t respond to requests for comment.
An apology, then another headache
Dave Meraz, an employee of the San Benito County Water District, had a simple statement for the inspectors who visited Hernandez Dam in July 2013: Sorry.
Inspectors had told Meraz the year before to fix multiple problems at the dam: cracks on the spillway, clogged drains and more. Meraz “agreed to make the necessary repairs and apologized for not completing the work since the last inspection,” inspectors wrote.
The problems weren’t cleared up until the March 2016 inspection. But that same inspection brought a new problem to light: Attempting to demonstrate an outlet valve for the inspectors, a dam employee was able to open the mechanism but couldn’t shut it back up.
The valve remained locked in the open position until shortly before last winter, said general manager Jeff Cattaneo.
Cattaneo said the valve, which wasn’t a safety hazard, would have been repaired sooner but the reservoir had to be empty first.
He said keeping tabs on Hernandez is tough. Located in a remote part of the county, Hernandez is 55 miles from district headquarters in Hollister. The dam has no full-time employees; it’s monitored remotely.
“It’s not like we go down there every single day,” Cattaneo said. “We go down there once or twice a month to do inspections.”
Shrubs in the spillway
The Metropolitan Water District of Southern California is a $1.6 billion-a-year behemoth with 19 million customers and considerable sway over state water policy.
But it’s been rendered seemingly powerless by vegetation growing at its dam near Temeculah in Riverside County.
Inspectors who visited Robert A. Skinner Dam in April 2013 noted that “a large shrub was seen growing in the spillway channel that needs to be removed.”
A year later, inspectors warned again about a tree growing in the spillway. By 2015, it had been removed, but in 2016 inspectors found a new tree growing inside the outlet where water is released. Last April, inspectors said the tree hadn’t been removed. Also, trees were sprouting again around the spillway.
Gordon Johnson, chief engineer at Metropolitan, said the agency hasn’t neglected the problem. Vegetation gets trimmed, it grows back.
“We don’t tear up concrete and be invasive about it. We control the vegetation,” he said. “We contain the growth and maintain it.”
Where are the data?
When dams are built, engineers often install devices that measure water pressure, movements within the dam caused by seismic activity, pressure changes or natural settling. Dam owners are supposed to report the data annually to state inspectors.
However, at least five dam owners went multiple years without reporting data, despite repeated complaints from inspectors. At Puddingstone and Cogswell dams, both owned by Los Angeles County, inspectors said the last instrumentation report they saw contained sensor data at least seven years old.
Foresthill Public Utilities District, owner of Sugar Pine Dam in Placer County, was told repeatedly to develop a plan for replacing its aging piezometers, which measure water pressure. When inspectors visited the dam in March of this year, five of the 16 piezometers were broken. One third of the piezometers at Guadalupe Dam, owned by Santa Clara Valley Water District, went unrepaired for three consecutive years.
All but three of the original 56 piezometers installed at Oroville Dam in the 1960s have stopped functioning, according to inspection reports.
Blackberry bushes and a clogged drain
When inspectors arrived in January 2014 at Iron Canyon Dam, a hydroelectric facility owned by Pacific Gas and Electric Co. in Shasta County, they found standing water in the spillway chute. A likely culprit: a clogged culvert.
When they returned a year later, they found the problem hadn’t been fixed. The same was true in January 2016 and May 2017.
PG&E dam safety official Eric Van Deuren said the culvert is located far from the dam and “doesn’t impact anything safety related.” The culprit: blackberry bushes that get cleared out but then pop up again.
“You know how fast those grow back,” he said.