Marin Voice: Supervisor shares next steps after tidal flooding in Santa Venetia

As the king tides peaked Jan. 3, residents of the Santa Venetia community near San Rafael watched floodwaters spill over and breach portions of the existing flood protection system. Streets flooded and water entered several backyards. I visited the neighborhood that day to see conditions firsthand and to hear directly from residents about what they were experiencing.

I want to thank Marin County Public Works and our emergency responders for their swift and effective response. Crews quickly deployed pumps, sandbags and plastic sheeting. They stabilized the situation by that evening.

While king tides were expected, water levels exceeded projections. Although the flooding was not catastrophic, it was understandably frightening and it should be taken as a serious warning.

This event underscores the urgency of moving forward with a permanent flood protection solution for Santa Venetia. The neighborhood depends on reliable protection from high tides, and the system currently in place is no longer sufficient.

The levee and pump systems that protect Santa Venetia were first built in the mid-1900s after major flooding in the 1950s. Following another serious flood in 1983, county officials added a 2-foot-high berm on top of the existing earthen levee.

Today, 600 homes rely on this berm for flood protection. It was built more than 40 years ago using compacted soil and wooden boards. It was never designed to serve as a long-term solution under current conditions. Over time, the materials have deteriorated, leading to increased water seepage beneath the berm and damage from rodents.

As storms grow more intense and tidal flooding increases, Santa Venetia now faces significant flood risk. A single “100 year” flood event could cause more than $150 million in damage to private and public infrastructure.

Flood Zone 7 currently receives approximately $700,000 per year in property tax revenue. That funding supports routine operations and maintenance such as pump stations, but it is not sufficient to finance a major capital project.

County leaders plan to replace the existing berm with a modern composite sheet-pile floodwall that meets the Federal Emergency Management Agency’s 100-year-flood protection standard. This engineered floodwall would provide stronger shoreline protection and significantly reduce the risk of flooding from overtopping and water seeping underneath. The design for the new floodwall is complete. The estimated total cost is approximately $25 million, reflecting inflation, construction costs, right-of-way acquisition, environmental permitting and mitigation, as well as engineering and construction.

To date, Marin County has secured $1 million in FEMA and Cal OES funding; $1 million from the American Rescue Plan Act; and $300,000 in county general funds to advance outreach, financing feasibility and environmental review

The project is designed, but we don’t have money for easements and construction.

We continue to pursue state and federal grants. However, in 2025 several FEMA prevention and mitigation programs were eliminated, making remaining grant programs far more competitive. Most of these grants also require the community to cover at least 25% of the cost.

Potential funding tools include bonds or low-interest loans to Flood Zone 7, supported by a new, reliable revenue source such as a special tax or benefit assessment. Both options would require voter approval.

Some have questioned whether dredging Gallinas Creek would have prevented the recent flooding. The primary flood risk in Santa Venetia is tidal flooding driven by ocean water levels, not creek capacity. Dredging does not lower the tide and doesn’t address the deteriorating berm, which remains the neighborhood’s main line of defense.

We have a path forward: a designed floodwall ready to move ahead. Jan. 3 was a serious warning, one we cannot afford to ignore, or allow to repeat itself. Preventing future levee failures and neighborhood flooding will require collective action.

Since September, we have held five Flood Zone 7 community meetings focused on the proposed floodwall. Thank you to everyone who participated. We will continue these conversations at the Santa Venetia “State of the County” annual meeting on Jan. 28. In addition, we will hold a webinar on Jan. 21 from 5:30 p.m. to 6:30 p.m. It will review the Jan. 3 king tides. More details on the webinar will be posted on the county website soon.

In February, a community survey will be sent to a representative group of residents in the Santa Venetia flood zone. If you receive it, please take the time to respond. Your feedback will help shape next steps.

Now is the moment to act. Together, we can protect Santa Venetia.

Mary Sackett is president of the Marin County Board of Supervisors. She represents Santa Venetia, Marinwood, Lucas Valley and portions of San Rafael.