Evolving Shorelines

Creating a shared vision for preservation and recreation at Bothin Marsh.


Conceptual Design Completed

The Bothin Marsh Open Space Preserve faces unprecedented challenges related to flooding and sea level rise over the next century. One Tam partners, Marin County Parks and Golden Gate National Parks Conservancy, in collaboration through the Evolving Shorelines Project have developed adaptation plans for the Preserve to ensure that the rich habitats and public access trails throughout the site are resilient to future sea level rise using nature-based solutions that enhance the ecosystem and benefit the broader community. This report documents the adaptation planning and design process that would serve as the foundation for future detailed design development.

JUNE 9, 2021

Evolving Shorelines Adaption Concepts Recommendations

In an online community meeting, the One Tam team presented an analysis of the Draft Adaptation Concepts for enhancing the Bothin Marsh Open Space Preserve’s tidal marsh and elevating the Mill Valley-Sausalito Multiuse Pathway. They discussed ecological and public access benefits, and other important considerations, such as community input, for each of the concepts. Watch a recorded video of the community meeting:

Adaptation Concepts June 8 Community Meeting Video 

To learn more about One Tam’s efforts at Bothin Marsh, please explore the Evolving Shorelines Storymap or you can view the previous Adaptation Concepts Presentation.

NOVEMBER 30, 2020

Interactive Story Experience

The One Tam team has released an online interactive story experience about Evolving Shorelines at Bothin Marsh. Learn about the history of the marsh, how rising tides are affecting recreation and wildlife habitat, and community collaboration to find solutions.

OCTOBER 14, 2020

Community Conversation

During a Zoom session on October 15, draft concepts were presented for the enhancement of Bothin Marsh Preserve’s tidal marsh, and elevating the Mill Valley-Sausalito Pathway. Members of the public shared comments on design options for adapting to sea level rise. Watch a video of the Zoom session.

JULY 9, 2020

Shared Vision Complete

This shared vision document for Bothin Marsh reflects community feedback–hundreds of people turned out to kayak, hike, play, and learn about the impact of climate change and sea level rise on this preserve. It is the collaborative effort of a broad coalition, working to envision the future of Bothin Marsh.

The Bothin Marsh Planning Memo identifies possible strategies for meeting the goals of the shared vision. This memo was drafted by consultants WRT and ESA, in collaboration with the Golden Gate National Parks Conservancy, via One Tam. 

To celebrate these milestones with the community, the Evolving Shorelines team hosted a Zoom virtual happy hour on Thursday, July 16, at 5:00 p.m. 

NOVEMBER 6, 2019

Board of Supervisors

The Board of Supervisors approved moving forward with development of conceptual designs for the Bothin Marsh Sea Level Rise Adaptation Project, based on shared community vision and research to date. The Golden Gate National Parks Conservancy will collaborate with the Marin County Open Space District on developing and completing conceptual designs, as well as continuing community outreach. The California Coastal Commission is in the process of recommending a grant which may help support this work.

SEPTEMBER 24, 2019


In 2019, visitors combined a reading adventure with a fun family walk along Bothin Marsh. Visitors of all ages enjoyed a series of reading panels featuring A Stone Sat Still, a new book by award-winning author and illustrator Brendan Wenzel. One Tam partners - Marin County Parks and the Golden Gate National Parks Conservancy - collaborated on the StoryWalk with local libraries and Chronicle Books. A series of events took place to celebrate the StoryWalk installation.

  • StoryWalk Reading, Mill Valley Library, October 3
  • StoryWalk Reading, Marin City Library, October 5
  • StoryWalk Reading, Bothin Marsh, October 5
  • Story Walk Reading, Bothin Marsh, October 19
  • Evolving Shorelines Happy Hour at Proof Lab, October 17


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 current sea level rise projections, the preserve will lose a significant amount of vital wetland habitat by 2030. The Mill Valley-Sausalito Multi-Use Pathway (Bay Trail) will also be greatly affected.

To better understand what is at stake, Marin County Parks and One Tam partners (National Park Service, California State Parks, Golden Gate National Parks Conservancy, and Marin Municipal Water District) worked with local scientists to assess existing conditions, potential future impacts from climate change and sea level rise, and potential adaptation challenges. This information was shared with the community during a series of Evolving Shorelines events.

Evolving Shoreline events were held in 2018 to share knowledge and engage the community in developing a shared vision for protecting this open space. The events offered hands-on experiential activities, like kayaking during King Tides. Attendees at the events also learned about nature-based solutions to address flooding, and collaborative adaptation strategies that would have multiple benefits to the ecosystem and the community. Feedback from the events is being used to develop a community vision that will inform future restoration design options at the preserve.