The discovery of previously unknown cracks and other concrete defects at Hodges Dam will extend ongoing repair work by several months, forcing San Diego officials to limit recreational activities on Lake Hodges and keep water levels low longer.
The newly discovered defects could prompt state regulators to downgrade the 104-year-old dam from “poor” to “unsatisfactory” and order all water to be removed, but city Public Utilities Director Juan Guerreiro hopes ongoing repairs will prevent that.
Get our important investigative reporting
Subscribe to Watchdog’s weekly newsletter for investigative reporting, data journalism and more.
From time to time, you may receive promotional content from the San Diego Union-Tribune.
City officials said they are working closely with the state Division of Dam Safety and local water agencies that use the lake, including the San Dieguto Water District and the Santa Fe Irrigation District.
The city already has a long-term solution: plans to build a Lake Hodges replacement dam about 100 feet downstream from the existing dam at a cost of about $180 million. But the repair of the old dam is necessary, because the new dam will not be completed for another 10 years.
Guerreiro described the newly discovered cracks as “surface defects in the concrete.” They were not discovered during a comprehensive assessment of Hodges Dam five years ago because they could only be seen when the water level was lowered in May for repairs.
The lake’s water level was lowered about 18 feet to 275 feet to facilitate repairs that were previously scheduled to be completed this fall. Newly discovered defects are expected to extend the repair work until the spring of 2023.
City officials said this week that extended renovations could jeopardize the lake’s usual February opening for recreation.
The lake, also called Hodges Reservoir, has been closed to boating and fishing since repairs began in May. Boating and fishing were expected to resume in February. San Dieguto River Park trails and facilities around the lake remained open during the work.
“Our top priority must be to preserve the integrity and safety of the 104-year-old Hodges Dam and the surrounding communities,” said Councilwoman Marnie Von Wilpert, whose district includes the lake. “While I understand this news is disappointing, public safety and the integrity of the dam must not be compromised.”
Guerreiro said there was no imminent risk of the dam breaching, which could flood nearby areas and threaten lives.
“While this is a setback for the project schedule, it is critical that we do a better job of ensuring that Hodges Dam remains safe,” he said. “The additional repair work will be worth the additional time it will take.”
The city’s nine reservoirs, all of which rely on dams, play a key role in the local water supply. They provide about 10 percent of the city’s water supply, and the rainwater they collect is much cheaper than the imported water the city relies on for most of its water.
Last year, San Diego launched a $10 million effort to complete risk assessments of all nine dams, which range in age from 62 to 110 years.
City officials say the assessments are expected to reveal problems that will require about $1 billion in repairs and upgrades over the coming decades — and possibly replacement of the dams as a last resort.
San Diego’s dams are among the oldest in the state and nation. State officials said two dams besides Hodges were also in poor condition — El Capitan and Lower Otay — and three were rated as “fair”: Moreno, Barrett and Lake Murray.
Only three dams — San Vicente, Miramar and Sutherland — received the state’s top rating of “satisfactory.”
Concerns about Hodges Dam increased in 2017, when defects at the Oroville Dam near Sacramento forced the evacuation of nearby areas. The two dams rest on the same arch structure, Guerreiro said.
Last year, San Diego received nearly $440,000 in state grants to pay for comprehensive reviews of five of the city’s nine dams — $97,500 each for Hodges, Morena and Lower Otay, as well as $81,250 for Barrett and $65,484 for El Capitan .
City officials are also considering low-interest loans from the state and possible federal aid to pay for dam assessments and repairs as needed.
Guerreira said city officials have lobbied for money from last year’s $1 trillion federal infrastructure law, but he said they haven’t come close yet.
While safety is the No. 1 factor in prioritizing the city’s dam repairs, city officials say another factor is the dam’s role in local water supply and reliability.
For example, the city’s two largest reservoirs, San Vicente and El Capitan, can hold 81 billion gallons and 37 billion gallons, respectively, but the smallest reservoirs, Miramar and Murray, can only hold 2 billion gallons and 1.5 billion gallons, respectively.