Drainage Management

Project Overview

The City of Sausalito's Gate 5 Area Drainage Management Study is a comprehensive effort to address recurrent flooding and future sea level rise risks in the Marinship/Gate 5 Road area. The Gate 5 Area Drainage Management Study aims to find combinations of engineering and ecological solutions to mitigate these risks, protect critical infrastructure, and ensure long-term resilience for residents, businesses, and the waterfront environment. The study will consist of a vulnerability assessment to fully understand land subsidence in the area, engage directly with Gate 5 Area interested parties, and create conceptual designs for both short-term and long-term improvement. The study goals include: reducing current and future flood risks and impacts, developing actionable, resilient drainage solutions, designing a project within regulatory requirements and permitting standards, enhancing public access, and supporting infrastructure reliability and community safety.

Project Area

The focus is on the Gate 5 Road corridor in Sausalito, including adjacent waterfront zones and drainage systems into Harbor Drive. This area is a mix of industrial, commercial, and ecological spaces that are essential to the City’s economy and character. 
Project Area

Upcoming Events

  • City Council Meeting: September 1, 2026 - City Council will review the draft Gate 5 Area Drainage Management Study and provide direction to staff for design documents for the recommended alternative. 

Past Events

  • Sausalito Flood Study: November 6, 2002 - PWA study
  • Sausalito Subsidence Study: August 2009 - Terrain Elevation Difference Analysis (1968-2007) - Towill study
  • Gate 5 Road Area Conceptual Drainage Study: May 17, 2011 -  West Yost study 
  • City Awarded US EDA Grant: August 1, 2024 - $614,400, to be Supplemented with $153,600 Local Matching Funds
  • City Council Meeting: September 3, 2024 - City Council Acceptance of the U.S. Economic Development Administration Grant Funds - Staff Report
  • Gate 5 Area Drainage Management Study RFP: Proposals due August 28, 2025 - RFP
  • City Council Meeting: September 16, 2025 - Professional Services Agreement Contract Authorization with WSP - Staff Report
  • Gate 5 Area Drainage Management Study Started: October 24, 2026 - WSP contract finalized
  • Gate 5 Area Study Fact Sheet: Fact Sheet
  • Gate 5 Area Study Community Survey: March 3, 2026 - Survey[open from 1/16/26 to 5/26/26]  - Community Survey Results
    • Online survey collected community input on flooding and drainage issues in the Marinship and along Gate 5 Road. Residents, workers, and business owners shared observations on where flooding occurs, how often it happens, and its impacts on daily life and property. Feedback also included existing mitigation efforts and ideas for long-term drainage solutions. Results inform development of the Gate 5 Drainage Management Plan
  • Draft Gate 5 Area Vulnerability Assessment: April 25, 2026 - draft Assessment becomes available. Draft Vulnerability Assessment
  • Gate 5 Study Community Meeting: April 29, 2026 - Community Event Flyer
  • City Council Meeting: September 1, 2026 - City Council to Receive and File the Gate 5 Area Drainage Management Study

Project Funding

In 2024, the City secured funding from the U.S. Economic Development Administration to support planning a new flood mitigation initiative in the Gate 5 Road, Harbor Drive area. This grant funds the development of preliminary concept plans for the area and may extend to include the Marinship Park.

Project Schedule 

In late 2025 City Council authorized a Professional Services Agreement with an international engineering and design firm, WSP. Since formally kicking off the project in 2025, the project is scheduled to finish in late 2026 with community engagement sessions and updates to City Council scheduled throughout the project timeline