One of the largest marine restoration projects in the U.S. is now in its second year.
The project—which is managed by the U.S. Army Corps of Engineers (USACE) and is funded for $545 million over five years—is a multi-purpose flood risk management, ecosystem restoration and recreation project. Phase 1 began on the outskirts of San Jose, the nation’s 10th largest and California’s third largest city. Phase I is a multi-agency partnership between the USACE, the U.S. Fish and Wildlife Service, Valley Water, and the State Coastal Conservancy.
As described by the community group San Francisco Bay Restore, “The Shoreline Project is an effort to provide flood protection, restore 2,900 acres of former salt evaporation ponds, and improve public access in the Alviso area of South San Francisco Bay. It will address the need for tidal wetland restoration, flood protection, and improved recreation connections in the South Bay. Ultimately, the project will restore 2,900 acres of managed open water ponds to tidal marsh. The Project aims to restore original tidal action and habitat; provide one-percent coastal flood risk management including improved shoreline resilience against projected sea level rise; and provide recreational enhancement opportunities and San Francisco Bay Trail connections.”
The start of Phase 1 was delayed by heavy rains but is now moving along. “After all of the rain, the site has finally dried out enough for the crews to clear and grub the site, install barriers and complete the prep work for removing the boardwalk,” the USACE wrote in an update.
The contract for the first phase, awarded to Maloney Odin Joint Venture, “consists of constructing approximately 1.6 miles of flood risk management levees with approximately 600,000 cubic yards of fill,” according to the USACE. “The complete project will construct approximately four miles of levees to reduce the risk of tidal flooding to the north San Jose area between the Alviso Slough/Guadalupe River and Coyote Creek, which includes 2,500 residents of the Alviso community, 3,000 commuters who work and travel through the area, the San Jose-Santa Clara Regional Wastewater Facility, and the Silicon Valley Advanced Water Purification Center. The project will also restore and enhance 2,900 acres of tidal marsh and related habitat lost to former salt production activities. Additionally, it will provide improved recreational opportunities and public access along the bay shoreline.”
Poseidon Barges Used on San Francisco Bay Shoreline Restoration
Maloney Odin Joint Venture, the primary contractor for the massive, multi-year Bay project, subcontracted with Blue Iron Foundations & Shoring LLC of West Sacramento, Calif. to install approximately 4,600 linear feet of of cofferdam for levee reconstruction. Retained water height varied up to a maximum of 16 feet. Sheet pile in lengths up to 45 feet was utilized. All work was performed using Blue Iron’s vibro-equipped Hitachi Excavator working atop Poseidon P2 barges
Reprinted from Marine Construction Magazine Issue I, 2023.
