San Rafael, CA – Marin County Department of Public Works (DPW) completed a series of four slide repair projects across Marin over the last five months. The four slides, in addition to eight other slide repairs that occurred in summer and fall 2017, were caused by the severe storms that hit the county in early 2017.
The completed repairs include this retaining wall installed along Marshall Petaluma Road.
The four newly completed sites are Sir Francis Drake Boulevard at Baywood Canyon, Marshall Petaluma Road at mile marker 8.24 in West Marin, and Red Rock Way and Los Ranchitos, both located in unincorporated San Rafael. Team Ghilotti was contracted to do the construction at all four sites, carrying a total cost of $1.4 million.
An eight-foot tall by 170-foot long retaining wall was installed at the Sir Francis Drake location. It is designed to catch potential future slides and features removable segments that allow for easy cleanup of storm debris, as well as efficient repairs, should that become necessary. A 40-foot long guardrail was also installed on the uphill side of the wall to improve overall traffic safety. The project, which cost $333,979, will be reimbursed with Federal Highway Administration funds.
At Los Ranchitos, an eight-foot tall by 64-foot long retaining wall was installed and it is designed to function similarly to the Sir Francis Drake wall. Additionally, the Los Ranchitos site included several drainage improvements along the front of the wall to address stormwater flow. The $157,205 project will be reimbursed by the Federal Highway Administration.
The $604,796 project at Red Rock Way required a specialized, 140-foot long wall to reinforce the roadway. A 60-foot culvert was also installed to help improve the drainage for the neighborhood. The project is being covered by the County’s Road and Bridge Rehabilitation fund, but is expected to receive partial reimbursement from the Federal Emergency Management Agency.
The damage to Marshall Petaluma Road necessitated an 86-foot long retaining wall to repair the damage and help protect against future sliding. A cable fence was also installed to improve safety. The $307,538 project is not eligible for federal funding and will be covered by County’s Road and Bridge Rehabilitation fund.
All four projects required repaving of the roadway adjacent to the newly constructed retaining walls. For the Sir Francis Drake and Marshall Petaluma projects, an additional 40 feet of road needed to be repaved at each end of the walls. To learn more about progress on County roads projects, follow DPW on Facebook and Twitter.