Canyon Road is a one lane, approximately 12-ft wide rural road that is the only entry and exit to residences along Canyon Road. Canyon Road was unsupported due to the recent movement of the embankment towards the creek and there was no shoulder remaining. The road had large cracks, signaling that the road would likely fail if there are no repairs made to the embankment. Repair and stabilization was necessary for maintaining the integrity of the roadway, public safety, and access for residents and emergency vehicles. The maintenance activities resulted in a more stable, less erosive environment decreasing the sediment load to the creek and improved water quality. The eroded area at the slip-out was reconstructed with a vegetated rock slope protection structure comprised of rock, back-filled, capped with soil, and revegetated.
Kings Mountain Road is a primary access road for La Honda residents as Highway 84 is often closed due to storm damage. A small slip-out along the road was threatening the integrity of the road and nearby culvert and the safety of road users. The eroded area at the slip-out was reconstructed with a vegetated rock slope protection structure comprised of rock, back-filled, capped with soil, and revegetated.
For the duration of the emergency repair work, materials and equipment were positioned on the paved roadway and shoulder. Heavy equipment was operated from the roadway. Equipment used to complete the repair included personal vehicles, Gradall, compaction equipment, and dump trucks. Equipment access to the drainage channel was required. Field personnel accessed the edge of slip-out by foot to install water quality protection measures such as wattles or silt fencing. Following construction of the bioengineered slope, the repair was covered with several inches of soil, covered with sterile rice straw, and covered with an erosion control blanket. Post-construction erosion control BMPs were installed to conserve soil resources and protect water quality. The reconstructed slope and all temporary surface disturbances were seeded with native plants. Work was conducted using BMPs detailed in the County of San Mateo Routine Maintenance Program Manual. A biologist was onsite to monitor all work.