Excavation began last week on the $110 million Phase 2 of the Silver Lake Reservoir Replacement Project in Burbank, CA. This segment includes the construction of a 68-million gallon concrete reservoir, which is about 25 percent larger than the 55-million-gallon Phase 1 tank, which cost $140 million and was completed last November 24, about one year ahead of schedule.

Phase 2 construction is being led WOL, a joint venture of Webcor Builders, Obayashi San Francisco and W.M. Lyles. SSC Construction of Corona. This is the same team that did Phase 1.  

Excavation for the new reservoir will take about 120 days and move somewhere in the neighborhood of 450,000 cu-yds of dirt. It will be led by Sharma General Engineering Contractors Inc., of Moorpark, CA. After this stage is complete, crews will start foundation and rebar work.

The new Reservoir will be 25 percent larger than the Phase 1 tank pictured above

And as they did on the previous phase, the team will build its own on-site concrete batch plant to avoid the risk of trucks getting stuck in LA traffic and missing important pours on a project that will consume an estimated 90,000 yards of concrete.

Vince Quinones, construction manager for WOL, says on Phase 2 his team will take advantage of lessons learned from Phase 1, which is practically an identical project, except for a 2,900-ft-long underground water-pipe connector tunnel. One of the things he says he learned was the importance of open communications with the owner / designer, the Los Angeles Dept. of Water and Power (DWP), and the Division of Safety of Dams (DSOD), which oversees mass-concrete water-bearing structures in the state.

"It is a pretty dynamic communication between all three of us to keep the project smooth and moving forward through submittals, RFI's and all the basic things," he says.

The multiphase Silver Lake Reservoir Replacement Project is located at the Headworks spreading grounds—a 43-acre former wetlands collecting site adjacent to Interstate 5 and the Los Angeles River. Phase 1 broke ground in 2013 and completed last November, and the current Phase 2 is scheduled to complete by end of 2017. Quinones says they will begin selecting contractors for the rest of the work on Phase 2 in November.

Phase 3 consists of the River Supply Conduit 1A West, Hydroelectric Power Plant and Regulating Station, which will break ground sometime in 2017; and final stage is Phase 4 - an Eco-System Restoration of the entire project site, which will include covering both reservoirs with about 10 ft of soil to create park-like amenities.

The new reservoirs are meant to eliminate contamination of drinking water by bypassing the now-closed Silver Lake and Ivanhoe reservoirs that were open-air. The project complies with new U.S. Environmental Protection Agency (EPA) water quality regulations.