About the Shoreline Study

Introduction

The South San Francisco Bay Shoreline Study (Shoreline Study) is a Congressionally-authorized study being performed by the US Army Corps of Engineers (Corps) together with local sponsors to identify and recommend for Federal funding one or more projects for flood damage reduction, ecosystem restoration and related purposes such as public access.

The Shoreline Study will be funded through a partnership among the U.S. Army Corps of Engineers (Corps), the Santa Clara Valley Water District (SCVWD) and the California State Coastal Conservancy (Conservancy). The U.S. Fish and Wildlife Service and other land-owning agencies within the project area will also be involved in the planning process.

The study will be performed through several “Interim Feasibility Studies”, the first of which will investigate flood protection for all Santa Clara County Baylands, from Palo Alto to Alviso, in addition to the restoration of former salt production ponds within the Alviso Pond complex and adjacent properties such as areas around Moffett Field.

Various flood protection strategies will be examined, such as increasing flood capacities of local creeks by widening the mouths of waterways and reestablishing historical flood plains. Although flooding risks from individual creeks have been reduced by a number of existing projects in the area, the Shoreline Study area remains vulnerable to tidal flooding. In Santa Clara County, there are several streams that carry runoff through the valley and north to San Francisco Bay. The two largest rivers — the Guadalupe River and Coyote Creek —have been retrofitted to provide flood protection to most communities along their banks, including the community of Alviso in north San Jose. However, it is the Shoreline Study that will examine tidally induced flooding in these communities.

To help guide the ecosystem-restoration and flood protection aspect of the planning effort, the Shoreline Study will incorporate findings from the South Bay Salt Pond Restoration Project, a Conservancy-led effort to restore historic wetlands on 15,100 acres of former salt-harvesting ponds in the South Bay. The Corps and the SCVWD are active project management team members of the Salt Pond Restoration Project. Extensive coordination has occurred, and will continue to occur, between the two projects.

Ecosystem restoration and flood protection will go hand in hand in the Alviso area. For example, as salt-evaporation ponds are breached and opened to the Bay’s tides to create tidal marsh, levees located between newly created tidal marsh and Santa Clara County communities could be replaced or upgraded to provide better flood protection.

Background

In 1992, the U.S. Army Corps of Engineers (Corps) could not within its policy guidelines economically justify developing a Federal flood management project along the South San Francisco Bay Shoreline, mainly because it determined that Leslie Salt would continue to maintain their existing (and un-engineered) salt pond levees due to economic interests. Although these salt pond levees were not engineered or built for the purpose of flood control, they provided incidental flood protection for the neighboring communities.

However, in 2003, the Federal and State government acquired 15,100 acres of the salt ponds in the South Bay from Cargill and began planning a restoration project that would ultimately impact the utility of those salt pond levees as flood control structures. As a result, the U.S. House of Representatives requested that the Corps review their previous study on flood control in the San Francisco Bay and expand its scope to include environmental restoration and protection, as well as tidal and fluvial flood protection.

The Corps completed an initial reconnaissance analysis in September 2004, which determined that due to the current and future anticipated conditions in the South Bay, it was likely that a Federal flood-control and ecosystem restoration project would be justified. In August 2005, the project partners completed a Project Management Plan to outline how the work would be conducted.

On October 24, 2005, the Corps, Santa Clara Valley Water District and the Conservancy kicked off the first study phase of the South San Francisco Bay Shoreline Study and are now in the preliminary stages of beginning environmental review. The project is currently undertaking “scoping” to determine the range of environmental issues to be addressed in the alternative development and analysis process.