Tiscornia Marsh Restoration and Sea Level Rise Adaptation
In June 2019, the Board authorized a grant of $968,916 to Marin Audubon Society to prepare technical studies, refine designs, and conduct environmental review and public outreach for restoration and sea level rise adaptation actions at Tiscornia Marsh. In April 2022, they augmented that grant with $3,082,000 to prepare permit applications, develop final designs, continue engaging community members, and begin construction for the restoration. In December, the Governing Board further augmented this grant with $386,000 to further the project objectives above and account for revised construction costs.
Tiscornia Marsh, City of San Rafael, Marin County, North Region
Planning/Design, Community Engagement, Construction
Safe, Clean Water and Pollution Prevention Program; Vital Fish, Bird and Wildlife Habitat Program; Integrated Flood Protection Program; Shoreline Public Access Program
In April 2022, the Governing Board authorized up to $3,082,000 to Marin Audubon Society to prepare permit applications, develop final designs, continue engaging community members, and begin construction for the restoration of Tiscornia Marsh. A further augmentation in December 2022 of $386,000 will help advance the project and cover revised construction costs. The project will build on and implement the conceptual design work funded with $968,916 by the Authority on June 7, 2019.
This project will prepare technical studies, refine designs, and conduct CEQA review and public outreach for marsh restoration and sea level rise adaptation actions at Tiscornia Marsh, which are expected to expand marsh habitat, increase flood protection, and provide public access at the mouth of the San Rafael Canal in Marin County.
The planning project is expected to evaluate feasibility and environmental effects of various potential improvements including:
- Expanding the existing marsh (up to 10 acres) through placement of beneficially reused dredged material;
- Restoring the six-acre diked marsh to tidal action;
- Constructing a new setback levee on the City’s property;
- Improving an additional 2,000 feet of the existing levee by raising it and incorporating an ecotone slope;
- Creating a coarse beach along the eastern marsh boundary to protect against marsh erosion and trap sediments;
- Creating a living seawall/rock jetty along the north marsh boundary in response to boat wake in the San Rafael Canal;
- Constructing a segment of the Bay Trail on the new setback levee; and
- Providing additional recreation amenities, which may include interpretive signage, benches, picnic tables, and a bicycle rack