ESCONDIDO SAYS LAKE WOHLFORD DAM REBUILD IS ‘SHOVEL READY’

Replacement project could begin in 2022 and cost $72 million

The city of Escondido is moving forward with plans to replace the Lake Wohlford dam, a structure built of earth and rock that has stood at its present location since 1895.

Lake Wohlford is about 5 miles northeast of downtown Escondido, just beyond city limits in the unincorporated area of San Diego County, and the dam is owned by the city. The lake has long served the city both as a recreational asset for boaters and fishing enthusiasts, and as an emergency storage reservoir to supply drinking water in case of a drought.

After nearly a decade of planning, design work and environmental review, the project is ready to move forward once funding is secured, said Christopher Mckinney, deputy city manager and Escondido’s utilities director.

“The replacement dam is shovel ready,” Mckinney said.

About 30 years after the original dam’s construction, the city in 1924 raised and enlarged the dam to increase its storage capacity to about 6,500 acre-feet, and a surface area of 225 acres, according to environmental documents.

However, a state safety inspection conducted in 2007 found that the dam addition could suffer a catastrophic failure in an earthquake with a magnitude of 7.5 or greater. As a safety precaution, the city lowered the water level to the height of the original dam, reducing its storage capacity by more than half, where it has stood for the past 14 years.

The city’s current plan is to build a new dam about 300 yards downstream, or west, of the existing dam, said Mckinney. The new dam will be built by rolling out layers of concrete, starting at the bottom and moving up. Once the new dam is completed, the top section of the old dam will be removed and a notch cut in the old dam to allow water to flow to the new structure. The bulk of the old dam will be left in place and submerged beneath the lake’s surface.

Construction of the new dam should take about two years, said Mckinney, and the city hopes to begin work early in 2022.

One issue that has faced city officials is the escalating cost of the project. The initial estimate for the project in 2012 was $30 million for construction. That figure has more than doubled to $72 million, Mckinney said, which includes the realignment of a section of Oakvale Road.

The road realignment would precede dam construction, and a bid for that work could come before the City Council as soon as this month, Mckinney said.

The city is looking at three outside sources of funding for the dam replacement, Mckinney said. The first is a $15 million state grant that has already been approved, but requires legislative approval for an extension of the grant’s eligibility.

The city is also working to finalize a federal grant and a low-interest federal loan to cover most of the remaining costs of the project, Mckinney said. Based on how much the city receives in grant funding, the amount of the loan would be adjusted to keep that source of funding as low as possible. The city also has set aside $16 million in its capital reserve fund that is earmarked for the project.

“I’m happy to say, I feel optimistic about all three of those sources of funding eventually coming to fruition,” Mckinney said. “With all three (funding sources) and our cash, we’ll be able to complete this project.”

Last year, as it considered the escalating costs for the project, the city looked at alternatives to building a new dam, such as rehabilitating the existing dam to meet current seismic safety standards. However, Mckinney said those alternatives were too costly and unlikely to win approval from the state Division of Safety of Dams, a regulatory agency that must approve any modification or construction of new dams in California.

“Unfortunately, we did not find any alternatives preferable to constructing a new dam,” Mckinney said. “We refocused our efforts on replacement. It was clear that was the most viable option.”

Once the new dam is built, the city can restore the lake to its full level, which will help increase water quality, increase the lake’s storage capacity, and enlarge the lake’s surface area for recreational users, Mckinney said.

The city also is working with the California Department of Fish and Wildlife (CDFW) to manage impacts to the lake’s surrounding wetland habitat.

The agency had concerns during the environmental review of the project that wetland formed when the lake was lowered in 2007 would be inundated when the lake level is restored to its full height. In response, said Mckinney, the city agreed to raise the lake level more slowly, allowing new wetlands to form as the existing habitat is submerged. This agreement significantly reduced the cost of mitigation.

Jennifer Turner, a senior environmental scientist/supervisor with CDFW’S San Diego office, said the agency was concerned about several plant and animal species that could be impacted by the dam replacement project, including Engelmann oaks, golden eagles, mountain lions and deer. CDFW also wanted to make sure that invasive, nonnative species such as red-eared slider turtles and bullfrogs were controlled.

Before the city moves forward with the project, Turner said, it will need to complete a lake and streambed alteration agreement with CDFW “to meet the needs of the project and avoid impacts to as many plants and animals as possible.”

Mckinney said dealings with both state regulatory agencies have proceeded smoothly.

U-T FILE In 2007, the water level at Lake Wohlford in Escondido was lowered when the condition of the dam came into question.