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Sonoma Public Infrastructure (formerly TPW)

Projects in Planning

Transportation and Public Works is now Sonoma Public Infrastructure - Website updates coming soon!

Projects planned for the future by Sonoma County Department of Transportation & Public Works.


Arnold Drive Bike Lane Project (C18122)

The Arnold Drive Bike Lane project will create a safe transportation corridor between Madrone Road and Country Club Drive by providing an additional five feet of pavement on either side of the road. The project also upgrades signage and striping along the route.


Chalk Hill Road Bridge Replacement

The existing bridge that carries Chalk Hill Road over Maacama Creek is a one-lane structure built in 1915. It is a County landmark and is eligible for inclusion on the National Register of Historic Places. The existing bridge has deteriorated significantly and is vulnerable to earthquakes as well as foundation scour and erosion along the south creekbank. The bridge has been determined to be unstable in an earthquake, and is threatened by erosion. The County seeks to replace the bridge with a new two-lane bridge.


Franz Creek Bridge Replacement

Sonoma County is currently working towards replacing the single-lane bridge over Franz Creek, on Franz Valley School Road. The bridge requires replacement due to scour deficiencies. Age and erosion from the stream are threatening the structural integrity of the existing bridge.


Freestone Flat Road Bridge Replacement (C11004)

The Sonoma County Department of Transportation and Public Works (DTPW) proposes to replace the existing Freestone Flat Road Bridge, which is a two-span, steel-girder truss bridge over Salmon Creek, in the southwest portion of the County.


Geyserville Drainage Project Development (E20004)

This project will gather information on the existing drainage system for the unincorporated town of Geyserville to identify problems leading to flooding issues. It will identify solutions to develop a list of projects to repair and improve drainage infrastructure in the town and its surrounding area.


King Ridge Road Bridge Replacement over Austin Creek

Sonoma County is currently working towards replacing the single-lane bridge over Austin Creek, on King Ridge Road. The bridge requires replacement due to scour deficiencies and seismic deficiencies.


Monte Rio Bridge Replacement

The County is actively working to engage the community regarding a new bridge that reflects local preferences, meets modern constructions standards, and protects the natural beauty of the region.


Permanent Asti Bridge

A Permanent Asti Bridge will provide an additional, reliable, year-round egress, particularly during disaster emergencies, which are an increasingly frequent threat. The total estimated project cost is $20 million, and the County proposes to fund $16 million. Property owners may be required to fund up to $4 million of project costs, dependent on any grant moneys that may be available,


Rio Nido Culverts Installation (C20012)

The 2019 winter storms in Sonoma County caused significant damage to homes and public infrastructure. The Rio Nido Culverts Installation project includes installation of a new storm drains down Bay Avenue and across Hay Lane in order to convey runoff away from the road surface to an existing concrete lined channel.


River Road Bridge Replacement over Gill Creek

Sonoma County is currently working towards replacing the two-lane bridge over Gill Creek, on River Road, Geyserville. The bridge requires replacement due to scour deficiencies and seismic deficiencies.


The Historic Watmaugh Bridge Over Sonoma Creek

The creek crossing at Watmaugh Road was a ford until the 1890s when, at the behest of local residents, the County financed construction of a wooden bridge. The Watmaugh Road crossing provided a more direct link to the south end of Sonoma and the lower Broadway area. The King Iron Bridge Manufacturing Company was awarded a $2,730 contract in 1891 to build the bridge. Under the 1919 Highway Modernization Plan, the County opted to replace the original bridge over Sonoma Creek as part of a series of improvements to what was then known as the Petaluma-Sonoma Highway. County Surveyor Edward A. Peugh drew up the plans for the replacement steel truss bridge in 1927, and on March 12, 1929, the Sonoma County Board of Supervisors awarded a contract of $14,783 to Walter Lewis Proctor to build it.