Commission approves $5.5 million supplemental allocation for Marin‑Sonoma Narrows project after bird‑nesting litigation settlement

The commission approved a $5.5 million supplemental allocation for the Marin‑Sonoma Narrows bridge project to cover additional construction support costs related to extended work under live traffic and protections for cliff swallows after legal action by local conservation groups.

Caltrans staff explained that the new bridge is being constructed in the footprint of an existing bridge under live traffic. The old bridge area is a nesting ground for cliff swallows; despite initial netting intended to exclude birds, many swallows entered the nets and roughly 70 birds were entrapped and perished. Local conservation groups filed lawsuits; to settle, Caltrans agreed not to demolish the old bridge during nesting season and must now manage additional construction seasons into later windows. Staff said construction capital budgets are sufficient but the department requires $5.5 million in construction support funds to pay for personnel and extended work across two additional construction seasons.

District and department staff recommended approval of the supplemental allocation; commissioners approved the recommendation in a recorded motion and no opposition was noted in the transcript. Commenters made light‑hearted remarks in the record about the per‑bird arithmetic, and staff said the department has provided alternative nesting accommodations though some birds have continued to use the old locations.

The supplemental allocation covers personnel and construction support costs; Caltrans plans to continue project delivery and will bring any future, claim‑related requests through the commission as required.