Caltrans, Highway 1 Upgrade Drainage PM 66.0

Caltrans, Highway 1 Upgrade Drainage PM 66.0

The proposed project is located on Highway 1 from PM 65.97 to 66.0, in Mendocino County. The purpose of the proposed project is to remove an 18-inch by 20-foot culvert and an 18-inch by 40-foot culvert and install two 24-inch by 72-foot smooth bore pipe culverts at PM 65.99. The culvert replacement is intended to improve existing drainage conditions adjacent to the highway, which is prone to flooding during heavy rainfall events. In addition, Caltrans proposes clearing sediment and vegetation from approximately 190 linear feet of the adjacent draininge ditches to improve capacity during storm events. The proposed project will result in temporary and permanent impacts to waters of the United States (U.S.) and waters of the State of California (State). The scope of work will include: trenching; culvert installation; headwall installation; and minor clearing of vegetation. A water diversion may be required for the proposed project. Caltrans will utilize Best Management Practices (BMPs) to provide erosion control and pollution prevention throughout the project area during construction. Caltrans has determined that temporary impacts to waters of the U.S. and waters of the State associated with the ditch clearing and culvert replacement would total 1,172 feet^2. Additionally, only eight feet^2 of waters of the U.S and waters of the state will be permanently impacted by the installation of the new drainage system.

Mendocino