The California Coastal Commission's (CCC) 1997 Coastal Development Permit requires the construction of a 150-acre kelp reef to partially mitigate the environmental impacts of operating the San Onofre Nuclear Generating Station (SONGS). The CCC asserts that operating the SONGS facility is responsible for a decrease in kelp in the nearby San Onofre Kelp Bed.

The Kelp mitigation reef, now formally called the Wheeler J. North Reef, is located in about 45 feet of water off of the San Clemente Beach.

The entire kelp reef will be constructed within an 862 acre parcel leased from the California State Lands Commission. The southern end of the Wheeler J. North Reef is about two miles north of SONGS and just north of San Mateo Point. The Kelp mitigation lease area extends north three miles to the City of San Clemente Pier.

The kelp reef is being constructed in two phases. Phase 1, constructed in 1999, covers 22.4 acres of sea floor. This was the experimental stage and 56 modules were designed to test the viability of using different densities of material and also compared quarry rock and concrete rubble.

These 56 modules, each 132 ft. x 132 ft. in bottom coverage, have undergone extensive study by a team of UCSB scientists retained by the Coastal Commission. The scientists completed their 5-year study in 2005. Their encouraging results show all experimental modules were very successful in supporting the requisite kelp plant density and diverse fish and invertebrate communities regardless of substrate type or density. A preliminary plan to construct the Phase 2 full-scale reef is complete and has been approved by the CCC Executive Director.

The 127.6-acre Phase 2 mitigation reef will use quarry rock from Catalina Island. A low-density mono-layer of 1 to 2 foot diameter rock will be used. The full-scale reef will require approximately 80,000 to 85,000 tons of material to be quarried on Catalina Island and transported to the construction site. The full-scale construction cost is estimated at $16 million with an additional $5-10 million allotted to the CCC staff for construction monitoring and post-construction performance assessments.

The California State Lands Commission amended their lease agreement with Edison in November 2006 to allow the Phase 2 reef to be constructed. Federal environmental review is now in progress and a new Coastal Development Permit is being sought in 2007.

The reef will not only satisfy the CCC-required mitigation of the environmental impacts resulting from SONGS' operation, it will also substantially enhance coastal natural resources by creating valuable habitat for fish and other marine organisms.

Observations made within
the San Clemente Artificial Reef
2002 vs 2005

Click the Play button at the bottom of the screen to play the video.