SCH Number 2015032089

Project Info

Title

Lagoons Slip and Slide (EA: 01-0B420)

Description

Applicant is seeking a Coastal Development Permit for repair and restoration of State Hwy 101 at two locations in the Big Lagoon area that were damaged by storm events in March 2011. Also a Special Permit for Design Review of the proposed improvements. At Location 1, PM 110.58, the applicant proposes replacing an existing 90-foot long, 18-inch diameter corrugated steel pipe, a damaged 18-inch downdrain and removal of invasive plants. The facilities will be replaced with a 24-inch diameter CSP culvert of a similar length and a 24-inch downdrain. Staging and storage will occur on previously disturbed graveled pullouts adjacent to roadway. At Location 2, PM 113.76, the applicant proposes to install approx. 600 linear feet of 42-inch culvert and a downdrain. Installation of new culvert and downdrain will use both trenchless cut and fill techniques. The downdrain will extend beyond the State right-of-way and discharge at a 241.5 sq. ft. energy dissipater that will extend to the edge of McDonald Creek Road on State Park property (APN 518-061-001). Also the installation of a radial array of 11 horizontal drains totaling approx. 1,755 linear feet that will dewater and stabilize the fill slope. The existing culvert and downdrain will be abandoned in place, and the existing drainage inlet will be removed. To install the proposed drainage facilities at Location 2 requires the excavation of a 1,600 sq. ft. jacking pit adjacent the existing culvert. Staging and storage will occur within the Truttman Sink Maintenance Yard, McDonald Creek Road and an existing unnamed access road. If any excess fill is generated by the project at either location, the contractor will be responsible for disposal at an approved location. During construction, temporary one-way traffic control restrictions will be used and construction warning signage will be installed. Construction is estimated to take between 40 to 60 working days and may span two construction seasons. The applicant will mitigate permanent and temporal impacts to wetlands and Other Waters of the US on-site and of-site. Off-site mitigation will occur at two locations: the Big Lagoon bog at Big Lagoon County Patrk and Strawberry Creek in Redwood National Park. Permanent impacts to wetland function will be mitigated by undertaking off-site vegetation enhancement at Big Lagoon bog. For the vegetation enhancement at Big Lagoon bog, the applicant has applied for a separate Coastal Development Permit and CUP (Application NO. 11253).

5 documents in project