Big Canyon Creek Restoration and Estuary Adaptation Project: Phase 2B/C Final Design and Permitting

Location: Orange County

Project Type: Restoration Planning

Status: Current

Habitat Type: Freshwater Wetland, Riparian, Tidal Wetland

Cost: $550,000

Funding Gap: $100,000

Area Affected: 9.2 acres

Project Footprint: 0.4 stream miles

Assembly District: 74

Senate District: 37

Congressional District: 48

Project Lead/Grantee:
Newport Bay Conservancy

The Newport Bay Conservancy (NBC) will prepare permits and final designs for the restoration of 9.2 acres of tidal wetland, freshwater wetland, and riparian habitats in the Phase 2B and Phase 2C project areas within the 60- acre Big Canyon Nature Park in the City of Newport Beach and County of Orange.

Phase 2B contains a fresh water pond that was created by the placement of dredge material and a downstream engineered outflow structure. Dry weather flows in the Big Canyon watershed contain elevated levels of selenium because the Monterey Formation has come in contact with increased groundwater levels and flows from urban development (e.g. increased irrigation). Continued selenium loading from the watershed has impacted the sediment and vegetation in the fresh water pond in Phase 2B and will require remediation as part of the restoration approach to Phase 2B. Phase 2C was a historical tidal salt marsh until natural tidal flow in Phase 2C was impeded in the mid-1900s with the construction of Back Bay Drive and placement of dredged materials from Upper Newport Bay, which resulted in loss of tidal wetlands.

As a part of the Phase 2 Planning effort, a feasibility study is underway to develop, assess and select remediation and restoration alternatives for the 4.83-acre Phase 2B site and 4.34-acre Phase 2C site. The Phase 2B Final Design and Permitting project will take the selected restoration alternative identified in the feasibility study and complete the CEQA, permitting and design. Biological and cultural surveys are also planned with an Initial Study as part of the grant funded by the US Fish and Wildlife Service and the State Coastal Conservancy. These planning efforts will lead to the implementation of the selected alternative that remediates the fresh water pond and restores coastal habitat at Phase 2B site, and that restores tidal flow and creates transitional zone for future landward migration of salt marsh habitat that is susceptible to sea level rise at Phase 2C site. This project phase is a part of the Big Canyon Creek Restoration and Estuary Adaptation project, which is being planned, designed, and implemented holistically as an integrated contiguous ecosystem.