Notice of Determination: Alpine Road Trail Improvements Project

Notice of Determination: Alpine Road Trail Improvements Project

Notice of Determination by the Midpeninsula Regional Open Space District to approve the Initial Study Mitigated Negative Declaration and adopt a Mitigation Monitoring Plan for the Alpine Road Trail Improvements Project. The Project proposes to implement grading, drainage, and erosion control repairs, and to conduct maintenance activities along approximately 7,400 linear feet of the existing Alpine Road Trail alignment. Additionally, the proposed project includes repair of a fill slope failure at the northern end of the Coal Creek OSP, where Alpine Road meets Ciervos Street (Site #21). This repair would primarily consist of the installation of two retaining walls. One wall would be constructed on the outboard edge of the road and have a height of up to 15 feet. This wall would be drilled and cast-in-place concrete pin pile wall with a grade beam at the road surface. A smaller wall (4 to 6 feet in height) would be installed to shore the inboard edge of the road. This wall would be a soldier pile wall with concrete piers, steel posts, and timber lagging. The proposed project would include replacing 14 old culverts, constructing surface drainage features (e.g., regrading road cross slope, installing reverse grade dips, and rocking the surface of problem areas), and re-routing the existing bypass trail. The proposed project would convert approximately 4,800 linear feet of the road to a trail, with a minimum width of 6 feet by removing fill on the outboard edge, extending from Site #10 to the confluence of the Bypass Trail.

San Mateo

Unincorporated