Bothin Marsh

Bothin Marsh is a well-loved stretch of shoreline that offers much in the way of recreation and wildlife, with unique plants and animals surrounded by urban development. With climate change and sea level rise, flooding is increasing in frequency and duration on the Mill Valley-Sausalito Multi-Use Path (Bay Trail) and throughout Bothin Marsh.

Bothin Marsh’s natural resources provide numerous ecological, economic, and social benefits to human visitors and neighbors. The land managers of Bothin Marsh Open Space Preserve have the responsibility of protecting an ecologically rich and beloved open space and recreational access. Bothin Marsh will likely see ten inches of sea level rise by the year 2030. One Tam, with community partners and community members, is urgently working to adapt the marsh ecosystem and the Bay Trail to sea level rise. Easily accessible and highly visible, Bothin Marsh is uniquely positioned to model how innovative, nature-based techniques can support the adaptation of this area and be applied elsewhere in our communities and throughout the Bay Area.

Project Leadership

One Tam partners – the Golden Gate National Parks Conservancy and Marin County Parks – are working together on the Evolving Shorelines Project at Bothin Marsh.

The Parks Conservancy provides support through fundraising, community engagement, communications and co-project management for this project. Bothin Marsh lies within the jurisdiction of Marin County Parks, land managers of this Open Space Preserve.

Restoration work at Bothin Marsh is primarily funded by Marin County Measure A. Past project funding has been provided by the California State Coastal Conservancy, the Marin Community Foundation, and generous support from One Tam members.

Project Contacts

Rob LaPorte, Golden Gate National Parks Conservancy
rlaporte@parksconservancy.org

Veronica Pearson, Marin County Parks
vpearson@marincounty.org

Project Updates

8/26/2021: Project partners release the Evolving Shorelines Adaptation Concepts report. This report documents the adaptation planning and design process that will serve as the foundation for future detailed design development.
6/8/2021: Project partners held a recorded, online community presentation to share the favored approach for adapting Bothin Marsh to sea level rise which has the Mill Valley-Sausalito Multi-use Pathway ringing the marsh.
10/15/2020: Project partners held a recorded, online community presentation to present three concept options to enhance the tidal marsh and elevate the pathway. A series of 2 ½ minute videos explain the conceptual options studied for sea level rise adaptation at Bothin Marsh Open Space Preserve and the Mill Valley-Sausalito Multi-Use Pathway:
- Concept 1: Raise Trail in Place elevates the pathway in place by building up the existing embankment would lengthen bridges to allow for restoration of tidal action to South Bothin Marsh.
- Concept 2: Span the South Marsh elevates the pathway with a causeway in the existing alignment allowing for restoration of tidal action and ecological connectivity to North and South Bothin Marsh. It also allows for connection of Coyote Creek and fluvial sediment delivery to the marsh.
- Concept 3: Ring the South Marsh re-aligns large segments of the pathway out of the marsh to existing high-ground and allows for full hydraulic and ecological connections between the creek, marsh, and bay. This trail alignment provides more connectivity to Tam Junction but also increases the length of the pathway and offers a different experience of the marsh.
6/22/2020: Project planners presented "Evolving Shorelines, Initial Planning Memo"
October, 2019: With input from the community, the One Tam partners put forth “Evolving Shorelines”, the shared vision for Bothin Marsh. With this vision, the project team began taking the next steps towards solutions with conceptual design and looks forward to getting community input on adaptation concepts.