Flooding shut Stanislaus County bridge. What will happen to it now

Bike riders approach the Hickman Road bridge over the Tuolumne River.
Bike riders approach the Hickman Road bridge over the Tuolumne River.

Stanislaus County has a project in the works to replace an important bridge over the Tuolumne River that was temporarily closed during the flooding last winter.

According to county Public Works, the foundation of the Hickman Road bridge has gradually eroded in the half century since the span was built near Waterford, just south of Highway 132.

In February, safety concerns prompted county officials to close the Hickman Road bridge for a time after the Don Pedro Dam spillway was opened, unleashing high flows in the Tuolumne River.

The bridge was deemed unsafe for traffic until the river’s flow fell below 15,000 cubic feet per second. “If the river rises to a certain high point, it could wash away the foundation and the bridge would topple,” Public Works Director Matt Machado said.

Studies also have shown the bridge is vulnerable to earthquakes.

Aside from the general safety of the Hickman Road bridge, the span should be wider by today’s standards to carry its north-south vehicle traffic (7,700 trips per day) while leaving room for pedestrians and bicycles.

The county will hold a public meeting Nov. 8 in Waterford to discuss the plans with residents in eastern Stanislaus County. The city of Waterford will participate in the 6:30 p.m. meeting at Moon Primary School, at 319 N. Reinway Ave.

Machado said the start of construction on the $23.4 million project is two years away. The county is wrapping up the environmental work, which requires federal and state approval before the county can proceed with the final design of the bridge.

“If people are interested in the environmental analysis or the schedule, we will be sharing that information at the meeting,” Machado said.

According to preliminary plans, large-diameter shafts will be drilled deep into the ground to support the new bridge. A contractor will build the bridge adjacent to the old one on the upstream side.

Drivers will use the old bridge until the new span and approaches are finished. The final step will be tearing down the 53-year-old bridge.

Funding for the project comes from a federal highway bridge program, a state seismic retrofit program and matching dollars from the county and Waterford.

Ken Carlson: 209-578-2321, @KenCarlson16