Design contract to replace aging Monte Rio bridge expected

The steel and concrete structure that spans the Russian River at Monte Rio gives the appearance of enduring strength and reliability - its thick, squat supports conveying steadfast immovability despite decades of use and the force of the river that runs underneath.

But the 1934 bridge is, in fact, nearing the end of its life, and county officials are gearing up to decide how to replace it, as soon as can be feasibly done.

Caltrans has set aside about $20 million in federal highway funds for the project, and the Sonoma County Transportation & Public Works Department is expected to award an engineering contract this summer for studies and design work that will guide decision-making over the next year or so.

The overall completion time is likely to be five years at least, Public Works Director Susan Klassen said.

“I feel like if we beat 10 years we’re doing good,” she said.

It’s already been nearly two decades since the state first deemed the bridge in need of seismic retrofitting, and it will be several years yet before the design, environmental review and permitting can be resolved and construction begins, county officials said.

That the existing bridge will still be in service while construction is underway means the new structure can’t be in the same location as the old one, likely raising right-of-way issues requiring negotiation. Special considerations related to the river environment and wildlife habitat protections also will complicate matters.

County officials held a public meeting in December to prime stakeholders’ imaginations. They promise additional opportunities for public outreach and input.

“Deciding on the bridge alignment will be one of the important goals for the designer to think about -where the bridge will go,” Engineering Division Manager Olesya Tribukait said.

Christened in 1934 with vodka and champagne at a dedication ceremony attended by California’s then-Gov. Frank Merriam, the Monte Rio Bridge, sometimes called the Bohemian Highway Bridge, has stood over the river and the popular community beach on its northern bank for 82 years, its vintage green trusses exuding an old-style nostalgia in keeping with the flavor of the town.

Swallows nest underneath, and beachgoers are accustomed to the shade it offers on hot summer days.

Though not exactly elegant, the landmark span makes for a picturesque scene against the rising, tree-covered landscape on either side of the river. Many in town are attached to it and not eager to see it go. But in addition to concerns about the effects of stress on 82-year-old materials, the 772-foot bridge is seismically deficient and vulnerable to erosion and other structural inadequacies, officials said.

Instead of anchored in bedrock, as the new bridge would be, its piers were built on wooden piles dug into the riverbed, where scouring and erosion have exposed some of the piles and could get significantly worse during flooding, Sonoma County Transportation & Public Works Department spokeswoman Jennifer Larocque said.

It is vulnerable to collapse in a severe earthquake, and the ground it’s built on is subject to liquefaction, as well. The bridge, located within 15 miles of three major earthquake faults, was identified by the state in 1997 as needing mandatory retrofits.

Metal fatigue and aging concrete also are expected to increase maintenance costs, officials said.

“It’s in bad shape,” Fire Chief Steve Baxman said. “If you‘re standing on it and a big truck comes over it, or a bus, the whole thing shakes.”

Many residents in town would like to see it salvaged as a bike and pedestrian bridge, similar to what was done in Guerneville, when the new bridge opened there in 1999.

Townsfolk there rallied to save the bridge from demolition and convinced the state to put $375,000 into its conversion, according to news accounts.

The “general consensus” is a desire to do the same thing in Monte Rio, said Dustin Gooler, a clerk at Bartlett’s Market on the south bank.

But county officials say it’s not feasible to salvage the Monte Rio span.

“This is one where we really can’t, because of the amount of work we’d have to do to make the structure safe even for pedestrians and bikes,” Klassen said. “It’s not the weight of the cars and trucks that are the problem. It’s the underpinnings that are really the problem on this one.”

You can reach Staff Writer Mary Callahan at 521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.