Caltrans is racing to shore up a damaged section of flood-prone Highway 37 ahead of what is predicted to be a notably wet El Niño winter.
An area near the Vallejo side of the commuter route between Solano County and Marin County has subsided because of overtopping water that was slow to recede after last winter.
The emergency repair project, estimated to cost $5 million to $10 million, will require a closure of the highway for several days, Caltrans said.
“We’ve had an excessive amount of water all the way through summer on State Route 37,” said Bart Ney, a Caltrans official. “We need to do repairs, and we’d like to get it done before the storm season really hits.”
If Caltrans did nothing, Ney said, “I’d expect to lose the route for many days.”
“We have in the past lost it for many days, and even just last year we lost it for a few hours,” he said. “The flooding is very real on Route 37.”
About 40,000 commuters a day use Highway 37. In recent years, the 21-mile corridor has been plagued with closures forced by water from San Pablo Bay.
The closures for the emergency project are planned for the 10-mile section between Sears Point and Mare Island.
First, Caltrans will close the westbound lanes only from 7 p.m. Wednesday to 4 a.m. Thursday. Then a 55-hour closure is planned from 10 p.m. Friday through 5 a.m. Oct. 26.
The project involves demolishing the median and installing temporary k-rail to shift all traffic onto the westbound lanes.
Once the eastbound lanes are cleared, crews will raise portions of the road by 3 feet to reduce the risk of flooding during high tides and storms. The work area encompasses about 1,300 linear feet.
While on the job, crews will assess if there is more they can do with the resources they have, Ney said.
The work is dubbed an “emergency maintenance” project and is separate from the suite of improvements known as the “Resilient 37” projects intended to relieve traffic and protect against rising water along the entire corridor. That plan involves raising the highway.
One of the larger efforts, called the “Sears Point-to-Mare Island” project, is expected to get underway next year.
Members of the Marin Conservation League have been critical of how the state and regional agencies are addressing the climate and traffic problem on Highway 37.
Kate Powers, a board member of the nonprofit, said Caltrans’ traffic advisory raises questions, including what plans are in place for stormwater runoff and what impacts will this have on bayside marsh habitat and species.
“We appreciate Caltrans’ preparations for this year’s El Niño storm season and we share concern that this segment flooded last January and that higher water sea levels on the east end of State Route 37 are already causing erosion,” Powers said. “Yet, raising portions of the roadway 3 feet for emergency preparedness seems more like a project than storm preparation and maintenance.”
By comparison, the most recent design of the same segment for the interim road-widening project includes raising low-lying portions of the pavement only 8 inches, she said.
“Overall, it’s becoming harder and harder to justify spending millions of dollars on a roadway that is not sustainable and will not be viable in the near future,” Powers said.
She said that the Marin Conservation League urges agencies to pursue only the long-term plan to raise the whole highway.
Ney said the emergency project is entirely within Caltrans right of way, and that it is working with all the regulatory agencies to ensure permitting compliance.
Caltrans is also working to ensure that the emergency project doesn’t undermine the “Resilient 37” projects or create any redundancies, he said.
“However, this wasn’t planned originally, this is an emergency repair,” Ney said. “So we’re gonna have to look and see what we can do with this in design for the other projects. But it shouldn’t set it back at all. I think it’s too early to say it’s a benefit.”
The Metropolitan Transportation Commission is one of the key partners in the Resilient 37 project program.
“We at MTC don’t expect the emergency work to undermine the Resilient 37 projects in any way,” said John Goodwin, spokesperson for the agency. “While Caltrans’ work next weekend may end up providing a small assist to the Sears Point-to-Mare Island improvements, it’s important to keep in mind that the work zone covers less than a mile of the roughly 10-mile corridor. Nonetheless, we appreciate the speed and the sense of purpose with which the state is moving to address a near-term issue ahead of the winter storm season.”
Another closure for the emergency project is planned from 10 p.m. Nov. 13 to 5 a.m. Nov. 15. The project is expected to wrap up by the end of the year.
Detours will be in place during the closure. Drivers traveling east should take Highway 121 north to westbound Highway 12/121 to Highway 29. The directions are reversed for westbound travelers.
Ney said a separate closure is planned on Interstate 80 near the Bay Bridge next weekend.
Drivers can check traffic updates at 511.org and at quickmap.dot.ca.gov.