Santa Venetia Floodwall Facts
Independent, plain-language information for the ~600 homes in the flood zone

The five facts every affected homeowner should know

1. The easement is the project

The current design requires a permanent 18-foot easement into 111 private backyards — forever. In five years of acquisition effort, the County has secured 16. The County has stated it will fund only voluntary easement acquisitions on this project — and because a flood barrier with a gap protects no one, every parcel matters: one holdout stalls the entire alignment. Until the easement problem is solved, no amount of funding produces a wall.

2. The easement requirement was assumed, not engineered

The County's stated reason for the wide easements is good public policy and future maintenance of the composite and timber wall system. Those maintenance needs are real for those materials — composite and timber deteriorate, rodents burrow, crews need recurring backyard access. But the County's March 2023 Basis of Design — the document that is supposed to justify every major design decision — contains no engineering analysis of the easement requirement, and the rationale depends entirely on the choice of wall material. The County's own published cost-by-phase figures put right-of-way at roughly $10 million — a major project component with no documented engineering basis.

3. No grant pays for easements

State and federal grants fund construction — not permanent easement acquisition. The ~$10 million right-of-way cost falls entirely on Santa Venetia residents through a future Prop 218 assessment, currently estimated at $100–150 per month per household for 30 years. That is $36,000–$54,000 per home.

4. There is no schedule and no finance plan

The County's own FAQ concedes there is no construction schedule and that 2028 is the soonest possible start. A draft finance plan promised by the end of 2025 was never produced. The County's FY2027–31 Capital Improvement Program lists the Santa Venetia floodwall as "TBD" with $0 programmed in all five years.

5. A reviewable alternative exists — and has not been examined

A steel sheet pile design (rather than the current vinyl/composite design) would not need broad permanent backyard access: steel does not rot, rodents cannot penetrate it, and maintenance is minimal. That concept — a narrow 6-foot permanent strip plus a temporary construction easement that is released after the work, at a preliminary target of $12–15 million total, on the order of half the assessment burden of the County program — has now been developed into a full draft Alternate Basis of Design: 35 pages, four appendices, a bottom-up cost model on current steel-mill pricing, and a photographic record of the entire alignment. It is entering professional review by Bay Area heavy-civil contractors and independent engineers, and will be published on this site when that review is complete. Neither the County's design nor the alternative has ever had an independent third-party review. The County's own Bolinas seawall (2014) is a steel sheet pile wall in Bay Mud that has performed for over a decade with minimal maintenance.

The reasonable ask: before any Prop 218 vote, the County should commission an independent engineering review of the easement requirement and the alternatives. If the current design is truly the only option, the review will confirm it. If not, the review could save the community years and millions of dollars.

Cost comparison at a glance

ItemCounty designSteel alternative (preliminary)
Total cost$25–30 million$12–15 million
Permanent easement18 ft into 111 backyards (~$10M)Narrow 6-ft strip matching existing berm
Monthly cost per household (30 yr)$100–150On the order of half — final figure pending contractor verification
Construction timeline2030+ (no schedule exists)18–24 months after easements
Independent reviewNever doneIn progress — contractor & engineer peer review

Alternative figures are preliminary and unfunded — which is precisely why independent review is the right next step.

The public record

Sources for every figure on this site:

Copies of these documents will be posted here as the document library is built out. Want a specific document in the meantime? Email wmta@wmta.com.