Supplemental Environmental Review and Subsequent Mitigated Negative Declaration for the Proposed Santa Venetia Floodwall - Supplement to the 2019 Gallinas Levee

The Marin County Flood Control and Water Conservation District Zone 7 is implementing the Santa Venetia Floodwall Project in San Rafael, California, to protect the Santa Venetia neighborhood from 100-year flood events for a 30-year design life. The project involves constructing approximately 7,800 feet of composite or steel sheet pile floodwall, with a maximum width of 14 inches, along the top of an existing earthen levee from 55 Meadow Drive to Pump Station 5. Key deliverables include the installation of above-grade steel sheet pile walls and the construction of a new concrete roadway and sidewalk featuring a passive flip-up floodgate at Meadow Drive to prevent rising floodwaters from entering the neighborhood. Construction is scheduled to begin on May 4, 2026, with an estimated duration of 90 to 120 workdays, typically concluding by October to fit within a single construction season. Work hours are established from 7 a.m. to 5 p.m., Monday through Saturday. The project is subject to strict environmental compliance, including a Supplemental Environmental Review and Mitigated Negative Declaration. Requirements include the employment of a qualified botanist and biological monitor for site inspections, adherence to a Stormwater Pollution Prevention Plan enforced by the San Francisco Regional Water Quality Control Board, and compliance with Clean Water Act Section 401 water quality standards.