San Diego has unveiled its long-awaited plan to prevent a major flood at Lake Hodges Dam: spend $30 million to $50 million to structurally shrink the unsound dam by lowering its spillway from 315 feet to 280 feet.
The proposed project, which will take an estimated seven years to complete, is unpopular with civic groups near the 108-year-old dam, who prefer a higher water level for recreational and wildfire-prevention reasons.
City officials say the seven-year project is considered an “interim solution” and that they are still pursuing a nearby replacement dam that might start being built shortly after the existing dam’s spillway is lowered.
Civic groups, including Friends of Lake Hodges, are questioning the financial sensibility of pursuing the interim spillway-lowering project when a long-term solution might be built so quickly afterward.
State and city officials agreed the spillway must be lowered as soon as possible as an interim solution, based on concerns that it now takes too long to lower the dam’s reservoir to a safe level in heavy rains.
That’s because the city now sends excess water out of the dam – deemed the most dangerous dam in California – using a 36-inch pipe. An unusually large volume of rain could overwhelm the pipe and cause major flooding.
Other options the city considered as interim solutions include widening the outflow pipe, adding a second pipe or punching a hole in the dam structure.
Officials from the California Division of Safety of Dams determined the only viable solution was lowering the spillway, which makes it essentially impossible for the water level in the reservoir to exceed 280 feet.
While the decision by city water officials to lower the spillway does not require City Council approval, the council will have to approve the design of the project and the funding for it before construction begins, likely in 2030.
Because the spillway won’t be lowered until roughly 2034, it won’t help the city cope with intense El Niño rains that weather forecasters are predicting for this winter.
But city officials say they’re still well-prepared.
“Operations staff closely monitor weather forecasts and coordinate with state and local partners to make controlled releases when needed,” the city said in a statement. “This includes continuous monitoring of reservoir levels, inflow forecasts, and storm conditions every rain season and especially during strong El Niño years.”
Now that the city has released its proposed interim solution, the focus shifts toward a much-anticipated analysis of whether to build a full-size replacement dam, something smaller or build nothing at all.
City officials say that analysis, which had been slated for release last summer, should be ready by next spring.
Building a new dam had been the city’s first and only choice until last year, when a sharp jump in cost estimates prompted the County Water Authority to renege on an agreement to help fund a new dam.
The new cost analysis determined the price tag had leapt from $275 million to somewhere between $474 million and $697 million.
The city’s plans have always called for the water authority to cover half the cost, for the city to cover 25% and for the Santa Fe Irrigation District and San Dieguito Water District to jointly cover the remaining 25%.
The city owns the dam, while the water authority and the downstream water districts have storage rights to the water in the reservoir. All the agencies have been sharing the costs to maintain the dam.
The recent controversy has sparked significant litigation, with the city suing the water authority over its decision to renege and the other water agencies suing the city for letting the dam reach such a state of disrepair.
In 2023, state officials declared Hodges the most dangerous dam in California, giving the dam’s safety level the unusually low rating of “unsatisfactory.”
The most likely timing scenario appears to be that the lowered spillway project will be completed while design work and environmental analysis are completed for the more permanent project — if there is a project at all.
City officials say the study will look at the possibility of not building a new dam. While that could increase flood risk in Rancho Santa Fe and other downstream areas, city officials note that the dam wasn’t built for flood prevention — it was built for water storage.
The civic groups lobbying for a new dam contend it would be a smart investment — one with high upfront costs, yes, but limited operating costs to capture millions of gallons of essentially free rainwater for ratepayers.
But with the first phase of the city’s Pure Water sewage recycling project scheduled to begin operating soon, the city’s water needs are shrinking. In addition, as much as $700 million for a dam to store rainwater might not be a smart investment.
The city could also build a smaller dam with a lower spillway that would be focused only on flood prevention, not water storage.
The civic groups say it’s shortsighted of the city to be keeping the water level in the reservoir at 280 feet – below the 295 feet they prefer — and a bad decision to re-structure the spillway to permanently limit it to 280 feet.
They stress that the existing 280-foot water level renders useless a taxpayer-funded $208 million pump built in 2012 to dump excess Lake Hodges water into the nearby Olivenhain Reservoir.
That pump has been unusable since the city was forced by the state to lower the reservoir’s water level in 2023.
Lowering the level has also limited recreational activities and, nearby residents argue, increased wildfire risk by exposing and drying out vegetation that had previously been under water.
The groups say wildfire risk should be a high priority, stressing that the area already lost several hundred homes during the 2007 Witch Creek fire.
The lower water level limits some boating and fishing activities and makes others impossible.
City officials say they’re on top of wildfire risk in the area.
In 2024, the city secured a $240.6 million federal loan for the dam replacement under the Infrastructure Investment and Jobs Act of 2021.
Because the dam replacement has been delayed and might never happen, city officials are exploring possibly shifting that money to another dam project.