2024 Rocky Creek Emergency Viaduct Monterey County 001 PM 60.0

The 2024 Rocky Creek Emergency Viaduct project in Monterey County is an emergency infrastructure effort by Caltrans District 5 to restore the southbound lane of Highway 1 at post mile 60.0 following a material slip that undermined the roadway. The project involves the construction of a permanent, three-span viaduct approximately 200 feet in length, supported by two abutments and two bents using cast-in-drilled-hole pile foundations and soldier pile and lagging cutoff walls. Additional scope includes repairs to the concrete seawall at the base of the cliff to protect the historic Rocky Creek Bridge and the new viaduct, as well as the installation of standard ST-75 bridge railing. Due to its location within the Carmel-San Simeon Highway Historic District, all work must comply with the Secretary of the Interior's Standards for the Treatment of Historic Properties. The project is subject to strict environmental regulations, including CEQA exemptions and NEPA categorical exclusions, with specific mitigation requirements for the Smith's blue butterfly habitat. This includes a 3:1 compensation ratio for lost host plants, five years of habitat monitoring, and the use of a service-approved biologist. Furthermore, the project mandates extensive aesthetic requirements, requiring concrete, metal, and rock elements to be colored or stained to blend with the surrounding natural geology and rural setting as determined by Caltrans District 5 Landscape Architecture.