Valley Water outlines plan to reconnect creeks to Alviso salt ponds as part of larger Bay restoration effort

Sunnyvale (Virtual) — Santa Clara Valley Water District (Valley Water) on Tuesday detailed the Calabasas–San Tomas Creek Marsh Connection Project, a feasibility-stage plan to reconnect local creeks to former salt ponds in the Alviso Complex to restore tidal marsh, improve sediment delivery and provide adaptable flood protection for Sunnyvale and neighboring communities.

Valley Water project manager Judy Nam said the effort would convert parts of Pond A8 and Pond A4 and portions of Harvey Marsh toward tidal marsh and transitional habitats while improving public access, particularly for historically disadvantaged neighborhoods in Alviso. "The intent is to establish tidal marshes before significant sea level rise becomes a critical challenge," Nam said.

The project matters because restored tidal wetlands can attenuate waves, trap sediment that builds elevation, and improve water quality — functions that planners say support both natural ecosystems and built infrastructure under rising sea levels. Christina Toms, an ecological engineer at the San Francisco Bay Regional Water Quality Control Board, told attendees the Bay historically held about 200,000 acres of tidal wetlands but now supports roughly 54,000 acres and that the region needs a landscape-scale, nature-based approach to regain resilience.

Valley Water summarized a multi-stage planning process that…