Until fall, traffic reduced to one-lane on Watmaugh Road Bridge in Sonoma

Watmaugh Road has seen better years.

In addition to the deteriorating Watmaugh Bridge, Watmaugh Road Bridge is partially closed, reduced to one lane of traffic, due to erosion, which has undermined its foundation.

While the Watmaugh Bridge is easy to see with its elegant design, the mucher smaller Watmaugh Road Bridge is hard to spot. It spans a small section of Sonoma Creek.

Janice Thomspon, deputy director of engineering and maintenance for Sonoma County Public Infrastructure (formerly Transportation and Public Works), said flows from the creek on the north side of the bridge have crumbled away the aging infrastructure. Heavy rains this winter caused further scouring of the bridge’s foundation, requiring extensive work.

“This has resulted in a reduced capability of the west-bound lane to carry traffic loads,” Thompson wrote in an email March 3. “The bridge was reduced to one lane to keep traffic on the portion of the bridge which remains at full carrying capacity.”

The Public Infrastructure Department has monitored the site for a few years now, Thompson said, and the department is working to repair the road by the fall. Significant engineering and permit approvals will be required to fix the road, making an exact timeline hard to pin down.

“The repair requires engineering on the hydraulics of the creek and structural engineering for the bridge foundation and environmental permitting to allow work in the creek,” Thompson wrote. “All of which take time to coordinate and complete.”

Until then, traffic on the popular road will be restricted to one lane, which has caused a back up of cars for weeks, especially in the bad weather. Drivers are advised to take Leveroni to cross town, or stick to State Route 121 if traveling south.

Contact Chase Hunter at chase.hunter@sonomanews.com and follow @Chase_HunterB on Twitter.