Hwy. 37 could be under water by 2050. Here’s how Caltrans plans to keep traffic flowing

Caltrans, in order to keep traffic flowing decades from now, intends to build an elevated road along Highway 37 to combat rising water levels, which are expected to eventually inundate the North Bay arterial.

The proposed project essentially stretches across the existing route along San Pablo Bay and through Marin, Sonoma, Napa and Solano counties.

It preserves travel patterns, allows landward marsh migration and is resilient to sea level rises, officials said in explaining its benefits.

“Putting the alignment up on a causeway allows us to not only address the sea level rise, but actually have considerable improvements to the natural hydrology and natural functions to occur,” Jeff Berna consultant who worked on a study for the project, said during the meeting.

The concept was one of 10 presented earlier this year, most of which were eliminated over months of discussion with North Bay cities, agencies and organizations.

The eliminated concepts mostly suggested creating routes via existing and new roads between Highway 101 in Sonoma and Marin counties and Highway 29 in Napa County.

Other plans focused on bridge construction between Novato and Vallejo.

Caltrans officials announced the final plan during a Sept. 14 public meeting about the rising water, which is expected to overtake Highway 37 by 2050.

The favored plan also proposes the route have a 60 mph speed limit, as well as two lanes in each direction with bicycle and pedestrian paths. The plan is in its early stages and officials haven’t identified a cost or funding source.

“Right now we sorta envision this taking 20 years to get this thing entirely built,” Chris Caputo, a co-lead on the project’s study, said during the meeting.

The effort is among several being discussed among multiple agencies and organizations in recent years.

Prone to flooding, Highway 37 has even been affected by inclement weather. In 2017, it had to be shut down for several weeks due to heavy rainfall.

In February, state Sen. Bill Dodd, a Napa Democrat, revived his pre-pandemic proposal to turn Highway 37 into a toll road in order to raise funds for projects that would prevent water-related closures.

The state Senate approved the bill in May but it did not make it past the state Assembly’s committee on appropriations last month.

Dodd’s press secretary, Paul Payne, said Friday the senator’s office will continue to look for solutions on the Highway 37 matter.

You can reach Staff Writer Colin Atagi at colin.atagi@pressdemocrat.com. On Twitter @colin_atagi