SAN LEANDRO -- Seismic upgrades to Chabot Dam are on track to begin next year, a project expected to bring a yearlong closure of Chabot Park and trucks loaded with dirt lumbering down Estudillo Avenue.

A final timeline for the project is not yet set, but East Bay Municipal Utility District officials expect work to get under way as early as fall 2014, starting with the addition of reinforced steel and replacement of old hardware at the dam's outlet tower. Work to excavate and replace unstable soil on the dry side of the dam will begin as soon as spring 2015 and finish later that year, district officials said.

The upgrades come after a 2005 seismic report found the outlet tower could be rendered inoperable and the dam wall could crack in the event of a large earthquake. Built in 1874 and owned by the EBMUD, Chabot Dam is located less than a third of a mile away from the Hayward-Rodgers Creek fault and less than 19 miles from the San Andreas fault, the report said.

EBMUD officials say the dam, holding back 3.3 billion gallons of water in the Lake Chabot Reservoir, is safe since its 30-foot-wide containment wall rests 23 feet above the water line and it is only at risk of settling 3½ feet in an earthquake, according to the report.

Still, the state Division of Safety of Dams, pointing to the seismic report, says the improvements must proceed.

The amount of dirt to be excavated could cover a football field with dirt 56 feet high and, depending on the size of the trucks used to haul dirt away, will take 6,000 to 12,000 trips, EBMUD officials estimate. That could mean 400 to 600 truck trips per day down Estudillo Avenue, district officials told the City Council in September.

EBMUD estimates that the work will result in a yearlong closure of Chabot Park at the east end of Estudillo Avenue starting sometime next year. San Leandro leases property from the utility district to operate Chabot Park, which is used by at least 4,000 visitors annually.

The utility district is drafting an environmental impact report that it will release in the fall followed by requests for public comment. Preliminary EBMUD estimates place the total project cost at $13.7 million, though the district is hoping a state grant will offset most of it.

Several City Council members expressed concern at September's meeting about the toll the project will take on the surrounding community and about the limited information provided by the district thus far.

Those concerns were echoed by members of the Parks Commission at a Jan. 2 meeting.

"I just want to know where are we at in this process?" said Parks Commissioner Evelyn Gonzalez.

Parks Commissioner Ed Shapiro recommended the district communicate with the Parks Commission and the local homeowners association about their proposed plans.

"It's a huge impact to these people and they don't even know about it," Shapiro said.

Commissioner Darryl Shields said he was wondering about the anticipated closure of the West Shore Trail, where his son regularly bikes.

Though plans are not finalized, utility district officials said they do not anticipate closures on Bass Cove Trail to the north and the Anthony Chabot Regional Park to the south, and no water outages are anticipated as a result of the project. Water in Lake Chabot Reservoir serves as an emergency water supply and limited recreational use, among other functions.

An EBMUD representative is scheduled to present an update on the project to the Parks Commission Wednesday night.

Ashly McGlone covers San Leandro, San Lorenzo and the Washington Township Health Care District. Contact her at 510-293-2463. Follow her at Twitter.com/AshlyReports.

updating the Chabot Dam project
An EBMUD representative will update the San Leandro Recreation and Parks Commission on the project at 7 p.m. Wednesday in the Helen Lawrence South Offices Conference Room at the City Hall Civic Center, 835 E. 14th St., San Leandro.
For more information, go to www.ebmud.com, click on "Construction Projects," then "Chabot Dam Upgrade."