January 2023 Emergency Storm Repairs, Higgins Canyon Road

January 2023 Emergency Storm Repairs, Higgins Canyon Road

On January 4, 2023 Govenor Gavin Newson proclaimed a state of emergency throughout the State of California to support the response to historic rain and flooding. Several road slip-outs occurred along Higgins Canyon Road and require immediate repair. 1) Near 2180 Higgins Canyon Road: The damaged embankment will be stabilized and reconstructed with an inboard steel soldier pile wall with concrete lagging and outboard stacked block retaining wall. Appropriate drainage to reduce hydrostatic pressure buildup behind the wall will be incorporated into the repair. A guardrail will be installed along the length of the repair. The inboard ditch relief channel will be reconstructed to direct flow to the next cross culvert on the road. 2) Near 2665 Higgins Canyon Road: Three consecutive slip-outs may be reconstructed with a steel soldier pile and lagging retaining wall with tiebacks for the entire length of the wall. Clearing and grubbing in adjacent areas may occur as necessary. A perforated drainage pipe may be incorporated into the repair. A guardrail will be installed along the outboard side of the road. 3) Near 1780 Higgins Canyon Road: Heavy rains and elevated creek flows resulted in the accumulation of excess woody debris at the base of the road slip-out near 1780 Higgins Canyon Road, and under the Mill’s Creek Bridge. Debris management and winterization efforts need to be conducted in order to prevent further scour at the existing slip-out and bridge to maintain structural integrity of the road. Post-construction erosion control BMPs will be installed to conserve soil resources and protect water quality at each location. All temporary surface disturbances will be seeded with native plants. Work will be conducted in accordance with BMPs detailed in the County of San Mateo Routine Maintenance Program Manual.

San Mateo

San Francisco Bay Area, Unincorporated

San Mateo