Caltrans will clean out culverts and ditches along Highway 1 at four sites on the eastern bank of the Bolinas Lagoon this fall, in hopes of preventing winter flooding. The Bolinas Lagoon Advisory Council requested the work, saying the constant action of flood waters on the bottoms of vehicles navigating the road is washing petroleum, brake dust and other toxins into the lagoon, a federally protected water body.
The council also drew attention to the threat to public safety during seasonal storms, such as the memorable one last April that washed out the Stinson Beach parking lot and temporarily closed that stretch of road.
At its meeting last week, the council voted unanimously to recommend that the county Open Space District Board grant Caltrans a permit to enter the area with several conditions, including a list of best management practices for the contractors.
“We are bringing this emergency, one-time-enter permit before the board,” said Veronica Pearson, a planner with the open space district. “Caltrans has not officially agreed to participate in the long-term discussion about ongoing maintenance yet, but it’s good that the agency has agreed to step in and take action now.”
The clean-out will focus on clearing sediment, debris and vegetation out of eight culverts and 4,050 feet of drainage ditches—in order to address the chronic flooding of Highway 1. Caltrans will use excavators, dump trucks, graders, loaders, tunnel muckers, vacuum trucks, chainsaws, chippers and haul trucks.
In their April letter, the advisory council asked Caltrans to collaborate with the North End Wetland Enhancement and Sea Level Rise Adaptation Project, a county project in the works since 2014 to address road flooding near the lagoon and restore surrounding habitat.
Most recently, in January, the board decided to focus on the first phase of that project and postpone finalizing two later phases, citing high costs, the challenges of coordinating with landowner agencies and possible conflicts with existing ecological and cultural resources.
The first phase includes removing the shortcut road at the Bolinas wye and restoring wetlands there to address roadway flooding, projected sea-level rise and habitat degradation.