Last Chance Grade Permanent Restoration Project

Last Chance Grade Permanent Restoration Project

Caltrans is the lead agency under CEQA and NEPA, as assigned by FHWA for the project. As shown in Figure 1, Last Chance Grade is the 3.5-mile-long section of U.S. Highway 101 (US 101) in Del Norte County (post mile [PM] 12.0 to 15.5) that runs between Wilson Creek to about 9 miles south of Crescent City. The Project area is almost entirely within portions of Redwood National and State Parks. The Project would realign the highway in response to landslide and roadway failures which have caused damage for decades. The objectives of the project are to: • Provide a more reliable connection • Reduce maintenance costs • Protect the economy, natural resources, and cultural resources. A geologic study in 2000 conducted for Caltrans by the California Geological Survey mapped over 200 historical and active landslides (both deep-seated and shallow) within the corridor between Wilson Creek and Crescent City. Over the years, Caltrans has conducted a considerable number of construction projects and maintenance activities in the Last Chance Grade area to keep the roadway open. Since 1997, landslide mitigation efforts, including retaining walls, drainage improvements, and roadway repairs have cost over $85 million. A long-term sustainable solution at Last Chance Grade is needed to address: • Economic ramifications of a long-term failure and closure • Risk of delay/detour to traveling public • Increasing maintenance and emergency project costs • Increase in frequency and severity of large storm events caused by climate change Over the past several years, Caltrans has considered multiple alignment alternatives with input from numerous project partners in seeking a long-term feasible and sustainable solution suitable for the unique geologic and natural features of the project area. As a result of these past alternatives screening processes, Caltrans has elected to move forward with the environmental review of two build alternatives, alternatives X and F (Figure 2). Alternative X would involve reengineering the existing roadway. Within a portion of Alternative X, the roadway would retreat inland (to the east) by approximately 130 feet to improve geotechnical stability and longevity. Alternative X would involve constructing a series of retaining walls (single and terraced) to minimize the potential for landslides on the roadway. Depending on feasibility, drainage improvements might also be included for this alternative. Alternative F would construct a 10,000 foot-long tunnel that would diverge from the existing roadway, near PM 14.06 and reconnect to US 101 near PM 15.5, thereby avoiding the portion of existing roadway most prone to landslides and geologic instability. The EIR/EIS will also study a No Project Alternative, which would entail no new long-term feasible and sustainable solution for Last Chance Grade but would instead be a continuation of ongoing maintenance and repair activities needed to enable ongoing roadway operations.

Del Norte

California Air Resources Board (ARB), California Coastal Commission (CCC), California Department of Conservation (DOC), California Department of Fish and Wildlife, Marin Region 7 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Natural Resources Agency, California Regional Water Quality Control Board, North Coast Region 1 (RWQCB), California State Lands Commission (SLC), California Transportation Commission (CATC), Department of Toxic Substances Control, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality, California Native American Heritage Commission (NAHC), California Department of Fish and Wildlife, Northern and Eureka Region 1 (CDFW)

California Native American Heritage Commission (NAHC), California Department of Fish and Wildlife, Northern and Eureka Region 1 (CDFW)

Transportation:Highway/Freeway (Addresses landslides affecting the highway)

Transportation

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Coastal Zone, Cultural Resources, Cumulative Effects, Drainage/Absorption, Energy, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Recreation, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire