1st Of 2 Bridge Replacements To Begin On Highway 12 In Sonoma County

SONOMA COUNTY, CA — Caltrans is set to begin full-time, one-way traffic control on state Highway 12 near Kenwood in Sonoma County starting on Monday, July 10.

The one-way traffic control will be in place 24 hours a day, seven days a week for a maximum of 45 days to allow crews to start demolition of the existing 46-foot-wide bridge and construction of the new 55-foot-wide Sonoma Creek Bridge.

Caltrans is replacing the bridge because of problems associated with "scour" — a process where fast-flowing water whirlpools around the bridge columns and footings, eroding the creek bed that supports the bridge. The bridge was built in 1922 and widened in 1950 and 1962. Over the years, the structural integrity of a bridge can be strained to the point where replacement is the best solution, Caltrans said.

After one-way traffic control is no longer needed, Caltrans will restore two lanes on Sonoma Creek Bridge and allow the free flow of traffic. Nighttime lane closures will continue until the remaining section of the bridge is completed.

Once two lanes of Highway 12 are restored on Sonoma Creek Bridge, Caltrans will begin the replacement of Hooker Creek Bridge, which is also on Highway 12 but near the City of Sonoma. Traffic will be detoured through Madrone and Agua Caliente roads, with the detours expected to last some 30 days. Local traffic will be permitted as far as the bridge, according to Caltrans.

Visit the Caltrans webpage for the State Route 12 Hooker Creek and Sonoma Creek Replacement Project for more information.