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Calabazas/San Tomas Aquino Creek-Marsh Connection Project

About This Project

The Calabazas Creek/San Tomas Aquino Creek-Marsh Connection Project supports the South Bay Salt Pond Restoration Project (SBSPRP), the largest tidal wetland restoration project on the West Coast. The work will realign Calabazas and San Tomas Aquino creeks to directly flow into the A8 Ponds located at the southern boundary of San Francisco Bay and the northern shoreline of Santa Clara County. The cities of Sunnyvale, Santa Clara and San Jose will benefit from this project as well as the Alviso neighborhood.

The project will provide enhanced environment, resilient flood protection, and improved access and recreational opportunities to the cities of Sunnyvale, Santa Clara and San Jose as well as the Alviso neighborhood.

California State Coastal Conservancy, the U.S. Fish and Wildlife Service, Caltrans, County of Santa Clara, City of Sunnyvale are among the partners of the project.

The project’s main objectives are to:

  • Ecologically restore and enhance the tidal and freshwater marsh and river habitat at the project area.
  • Provide resilient flood protection that will adapt to projected sea level rise.
  • Reduce maintenance needs and associated habitat disturbance for lower Calabazas and San Tomas Aquino creeks.
  • Provide enhanced public access and improved trail improvements.

Current Project Phase:

Planning: Spring 2022-Summer 2024
Design: Spring 2024-Summer 2026
Construction: Spring 2027-December 2028

Current Estimated Cost:
Planning through Design Phases: $8 million

Grant Funding:
Measure AA administered by San Francisco Bay Restoration Authority: $3.37 million

Prop 1 Grant administered by California Department of Fish and Wildlife: $500,000

Project Map
News and UpdatesNews and Updates
Reports and DocumentsReports and Documents
Environmental and Community BenefitsEnvironmental and Community Benefits
History and BackgroundHistory and Background
News & Updates

Valley Water is in the process of acquiring consultant services for planning, monitoring and modeling the project.

Request for Proposal for Modeling is available here and the bidding has closed on April 27.

Request for Proposal for Planning and Monitoring is available in this link and the bidding has closed on April 12.


Any questions regarding these solicitations are to be directed via email to: Alicia Fraumeni, Contracts Unit at [email protected]


For more information: 

  • Judy Nam: Senior Water Resources Specialist, Water Resources Planning and Policy Unit
    Cell: (408)728-0451
    Reports & Documents

    Studies and Reports


    Environmental & Community Benefits

    The Project will restore and enhance up to 1,500 acres of tidal marsh, seasonal, and brackish marsh and riparian habitat. The self-sustaining tidal marsh will provide more than natural resilient flood-protection. The connected creek-marsh-bay system will benefit native fish and wildlife, including, federal and state Endangered Species Act-listed species, such as the Ridgway’s rail, salt marsh harvest mouse, and Central California Coast steelhead. 

    Project benefits will include enhanced opportunities for public access to the area promoting environmental education and recreation.  Nearby communities including Alviso, a historically disadvantaged community suffering from a history of disinvestment and social injustice will benefit from resilient flood protection and enhanced public access to the restored natural tidal marsh. Economic benefits to the Alviso community will include construction period expenditures in the short term and increased recreational use of the area in the long-term. The Project would also benefit the regional economy by reducing future creek maintenance costs. The expected savings from avoidance of flood damage would be substantial, especially given the tremendous amount of high value property development in this portion of Silicon Valley.

    History & Background

    The project was formerly known as the Salt Ponds A5-11 Project and changed to current name to better highlight the project purpose and align with regional documents such as the 2015 Baylands Goals update and Sediment for Survival.  Previously the Salt Ponds A5-11 project focused on our strong partnership with SBSPRP and USFWS and Valley Water’s support to provide dirt to USFWS to maintain the existing berms around Ponds A5-11 to prevent degradation in current levels of de facto flood protection that the former salt ponds provide. With construction of Phase 1 of the Shoreline Project now underway to provide flood protection to the Alviso area, USFWS is now shifting focus with a stronger intent to restore the A8 Ponds. 

    The A8 Ponds were once tidal marshes that were converted to salt production ponds and diked off from the Bay more than a century ago. The Calabazas and San Tomas creeks used to discharge into tidal marshes at the edge of the San Francisco Bay but were realigned years ago to bypass the ponds and discharge directly into Guadalupe Slough and the bay. This resulted in unnatural flow lines with sharp bends that reduced the amount of water that flowed through the creeks and resulted in large deposits of sediment in the channels. Valley Water periodically removes the accumulated sediment at great expense to keep the channels free and prevent increased flood risks to local development. Valley Water’s project is now focused on connecting Calabazas and San Tomas creeks to the A8 Ponds to create a tidal marsh habitat.

    The project will be the first creek-marsh connection project in the lower South Bay and has received significant grant funding for the planning through design phases