Environmental Consulting

Alton Parkway Extension Habitat Restoration | Orange County, CA

OC Public Works


CEQA Documentation (EIR)
Habitat Mitigation Planning
Restoration/Enhancement Planning
Invasive Species Management Planning
Restoration Monitoring
Agency Coordination and Compliance

Innovative Approach to Wetlands Mitigation

The Alton Parkway Extension improves traffic by closing the 2.1-mile gap between Alton Parkway and Irvine Boulevard, just south of the State Route 241 toll road.

BonTerra Psomas initially completed the Environmental Impact Report (EIR) and supporting biological and cultural services, then performed habitat restoration/mitigation planning and design in support of federal and State regulatory permitting and authorization. As part of the latter effort, BonTerra Psomas is completing both on-site and off-site mitigation monitoring programs for the County of Orange portion of the project.

The on-site mitigation program provides an innovative approach to wetlands mitigation with the construction of a wildlife corridor that will connect Borrego Canyon Wash with the proposed Great Park wildlife corridor. The Alton Parkway/Great Park wildlife corridor system would provide for safe passage of wildlife species between the Cleveland National Forest and the Central-Coastal Natural Community Conservation Plan reserve areas to the east and Crystal Cove State Park west of the project site. The off-site mitigation program will enhance riparian woodland through the eradication and control of 14.41 acres of non-native plant species within an 82-acre study area along Aliso Creek.