Marin City Stormwater Plan (Sample)

The current Marin City Stormwater Plan, which is being initiated in Spring 2023, will build on prior studies, including:  

• 2018 Wood Rogers Marin City Drainage Study 
• 2018 Marin City People’s Plan Designing our Own Solutions Report 
• 2022 Schaaf & Wheeler Donahue Bypass initial concepts  
• 2023 Siegfried Marin County Green Stormwater Infrastructure Development Study 

 (Studies available to the public upon request) 

 A major distinction is that the Stormwater Plan will focus heavily on community education, outreach, and input, exploring the ideas and priorities generated by community engagement. The Stormwater Plan also corresponds with other local projects that have been developed since the completion of the previous studies and stormwater planning efforts.   

 The Stormwater Plan will also update the hydraulic model for the watershed, providing a more holistic assessment by updating pipe information, including various smaller stormwater pipes, and additional drainage features that were previously not part of the model. Additionally, the new planning process will reevaluate potential public stormwater easements for implementing future flood mitigation infrastructure.  

The Marin City Stormwater Plan will result in a public stormwater infrastructure plan of potential projects that reflects direct input from Marin City residents and organizations in partnership with the various public agencies that have responsibilities in the watershed.

This public stormwater infrastructure plan will recommend various flood risk reduction projects and drainage improvements for consideration by local and state agencies. However, the Stormwater Plan will not commit the County or District to implement the specific recommendations or projects.

Following completion of the Stormwater Plan, if any of the identified projects/recommendations are pursued by local, state or federal agencies, then the respective agency would need to conduct more detailed design work, as well as secure construction funding sources. Additionally, should an agency proceed with implementing a specific project/recommendation, that agency would be required to first complete a California Environmental Quality Act (CEQA) document, and potentially obtain National Environmental Policy Act (NEPA) clearance if federal funds are being used, such as any Federal Emergency Management Agency (FEMA) grants.

 The geography of the watershed, in which rainfall channels its way from the surrounding hills down through Marin City and out to Richardson Bay, creates complex challenges for developing flood risk reduction measures. The densely populated area was built upon wetlands before contemporary construction methods and stormwater runoff can overwhelm the neighborhood’s aging drainage system and lead to localized flooding, particularly when storms and high tides coincide.   

  To successfully design and implement any long-term flood mitigation efforts that consider future sea level rise projections, it is crucial to plan for as many variables as can be identified. Past studies have identified elements that need to be addressed in the current Stormwater Plan’s process, as well as the critical involvement of Marin City residents and stakeholders, which will enable development of designs that specifically address the concerns and needs voiced by the community.  

Additionally, the high cost of potential projects poses a hurdle. The timing of implementing projects hinges heavily on funding availability. The anticipated heightened costs of flood risk reduction projects in this complex watershed means that the County and the District’s funds may require significant state and/or federal funding assistance. State and federal funding sources, such as grants, can take a significant length of time to secure.

The current Stormwater Plan aims to reduce the potential timelines for securing grants by building upon evidence and data from previous studies and exploring ways to address historically flood-prone areas, such as the upper watershed and the Drake/Donahue intersection.

Marin County Flood Control District is requesting an increase in FEMA grant funds to design and construct various stormwater drainage improvements in and around the Marin City Pond, which  includes a pump station. While awaiting next steps on those potential projects, the District is also implementing a “portable pump station” on Donahue Street near Drake Avenue, which will help reduce flooding depth and duration along the thoroughfare. There is also an environmental clean-up dredge being considered with funds set aside by the State.  

 CalTrans’ Office of Advanced Planning is using State transportation funds to conduct sea level rise planning specifically on State-managed lands and rights-of-way in the area, including the on- and off-ramp to Marin City.  Please check with Caltrans directly for more information on that effort. 

 The Marin City Stormwater Plan will coordinate with the Federal and State planning efforts while focusing on local roads and infrastructure within Marin City. However, the Stormwater Plan is a separate undertaking from the work being done in relation to the $10 million in state funding secured by Senator McGuire in 2022.   

Three community meetings will be held in Marin City as part of the Marin City Stormwater Plan process during 2023 and 2024. You are encouraged to attend and provide input during those meetings, no registration is required to attend as meetings will be listed from the project page and notifications prior to the meeting will be emailed to the Flood Zone 3 email subscribers (register here). You are also welcome to submit comments, questions, and concerns at any time using the Contact Form on the project webpage. 

There are two ways to stay informed about this project: 

• Sign up for email updates to receive notices of upcoming Flood Control Zone 3 related community meetings and events, which will include updates specific to the Marin City Stormwater Plan. 
• Visit the project webpagehttps://marinflooddistrict.org/marin-city-stormwater-plan-meetings/ regularly for updates from past community meetings, updates following Task Force meetings, upcoming community meeting details, and general progress announcements. 

Draft and final plan documents will be posted on the project webpage as they become available. Please check the webpage regularly for progress updates. Availability of the draft and final plans will also be announced via News Releases from the District. Please sign up for the Flood Control Zone 3 email list to be notified on this topic.