West Marin residents bracing for the Green Bridge replacement in Point Reyes Station can add another traffic worry to their checklist. Shortly after that historic span is replaced, the county’s Department of Public Works plans to replace a less noteworthy bridge that crosses Olema Creek on Levee Road.
The bridge is 99 years old, and engineers have concluded that it is both functionally obsolete and too low to clear flood levels during a 100-year storm.
The new bridge, which qualified for a federal highway bridge program, is expected to cost $3 million. The old bridge is 24 feet wide, with 1-foot shoulders. The new bridge will be wider, longer, and higher, with a width of 38 feet and a length of 77 feet. Its two 11-foot travel lanes will be flanked by 6-foot shoulders. Its concrete components will be cast on site.
The bridge was built in 1930 and extended in 1967. Erosion has occurred around the piers supporting it and some cracking has occurred on its underside. The structure scored 51 points on a 100-point scale that Caltrans uses to measure bridge adequacy.
The project will not resolve the flooding that often occurs in rainy seasons on Levee Road. The D.P.W. has no immediate plans to raise the roadway, though it does plan to pave and smooth the existing surface.
“As planning and evaluation are still underway, it is not yet known whether any long term improvements would address the broader flooding issues in the area,” said Robin Bartlett, assistant director for D.P.W.
The bridge replacement work will be done during the summer, when the water level is low, and the creek will be temporarily diverted during construction. Olema Creek crosses beneath the road and connects with Lagunitas Creek, which runs along Levee Road and into Tomales Bay.
“The project is currently in the environmental review phase, so the final bridge design won’t be set until that process is finished and any additional required environmental measures are incorporated,” Mr. Bartlett said. “After the new bridge is built, disturbed areas will be restored, and the project will include environmental mitigation to replace vegetation and protect habitat.”
A preliminary survey found no rare or vulnerable plant species at the site, but the habitat is suitable for a variety of special-status animal species, including coho salmon and steelhead trout, red-legged frogs, California freshwater shrimp, pond turtles, yellow warblers, various bat species, and dusky-footed woodrats.
The county is taking public comment on the project’s draft environmental review until July 1.
Both the Olema Creek and Green Bridge projects will force drivers traveling between Inverness and Point Reyes Station to negotiate detours through Olema. The replacement of the Green Bridge is expected to begin in the summer of 2027 and last about a year and a half. The Olema Creek span is expected to be replaced beginning sometime in 2028 or 2029 and will take roughly six months to complete.
While Levee Road is obstructed, motorists will be forced to detour along Highway 1 and Bear Valley Road, costing them an additional 10 minutes. That’s roughly half as much time as the Green Bridge detour, which will require cars to climb Olema Hill and loop around Platform Bridge Road and Point Reyes-Petaluma Road to get from Inverness to Point Reyes Station. The Green Bridge detour is expected to be in place for about three weeks, while the length of the Olema Creek detour has yet to be determined.
For information, go to https://tinyurl.com/OlemaCreekBridge