Bridges

About

Bridges on the Sonoma County road system are maintained by the Roads Division of the Sonoma County Department of Transportation & Public Works (TPW). TPW currently maintains 328 bridges, which serve over 800,000 trips per day on average.

Bridge Inspections

In California, all designated bridge structures are inspected by Caltrans, the state transportation agency, on a two-year cycle. A bridge inspection examines the structural integrity of each bridge, and is coupled with ongoing staff inspections to form the basis for the County’s bridge program.

Types of Work

Bridge Scour

Stabilization of areas where material is eroding away from the bridge foundation; or, removal of sediment such as sand and rocks from around abutments and piers.

Resurfacing

Removal and replacement of damaged concrete, as well as application of surface treatments such as methacrylate resin.

Seismic retrofits

Modifications or enhancements to the existing structure in order to reduce susceptibility to earthquake damage.

Reconstruction

Complete removal of the entire bridge structure; construction of a new bridge.

Past Bridge Projects

Wohler Road Bridge Replacement over Mark West Creek (2020)

This project includes construction of a new two lane road bridge over Mark West Creek, on Wholer Road. The new bridge will be constructed on a new alignment and the current bridge demolished only after construction of the new bridge is complete.

Chalk Hill Bridge Replacement (2019)

Replacement of the one-lane structure built in 1915 by a new two lane bridge.

Monte Rio Bridge Replacement (2018)

In Summer 2018, the Department of Transportation and Public Works conducted technical studies and community workshops designed to inform the project and the development of design alternatives. Environmental studies will take place from 2019 – 2021, with a final bridge design expected in 2022. Bridge construction is expected to take place in 2023-2024.

Hauser Bridge Replacement (2017)

Replacement of the one-lane bridge over the South Fork of the Gualala River with a two lane, 29 foot wide and 165 foot long steel bridge.

Bridge Summerhome Park Road amd Neeley Road (2015)

Road Commissioner project declaration for bridge repairs on Summerhome Park Road and Neeley Road as well as an asphalt overlay of 1,800 section of Woolsey Road extending south from the intersection with River Road.

Bridge Maintenance (Austin Creek Road and Annapolis Rd (2014)

Bridge Maintenance (Scouts Camp Road, Starrett Hill Drive, Pacific Avenue (2014)

Porter Creek Bridge Replacement Project (2013)

Complete reconstruction of the Porter Creek Road bridge over Porter Creek.

Annapolis Road Bridge Seismic Retrofit (2011)

Construction of earthquake upgrades on the Annapolis Road Bridge over the Wheatfield Fork of the Gualala River.

Roadway & Bridge Surface Preservation Program (2010)

This project included basic maintenance measures on twenty (20) different bridges. Work done included cleaning expansion joints and replacing joint seals, and cleaning and retreating bridge decks, as well as repairing damaged concrete.