10. Overriding Considerations

Pursuant to CEQA Guidelines § 15093, the Commission may only approve a project that results in significant and unavoidable impacts upon a finding that there are overriding considerations. As discussed previously, this project is needed in order to reduce the possibility of overloads on existing 220 kV transmission lines in the Big Creek Corridor. On June 24, 2004, the California Independent System Operator Board of Governors approved the looping of the Big Creek 3-Springville 220 kV transmission line into the Rector Substation as the preferred long-term transmission alternative to address identified reliability concerns. The Big Creek 3-Rector 220 kV transmission line's maximum allowable capability under base-case conditions is 700 MW, and the recorded peak load at Rector Substation was 701 MW on July 10, 2008. Under the worst-case single contingency outage scenario (one transmission line out of service), the Big Creek 1-Rector 220 kV could exceed its emergency rating of 106%. The worst-case double-contingency outage scenario (two transmission lines out of service) could result in the need for rolling outages and/or customer blackouts in the area served by Rector Substation. For these reasons, we find that there are overriding considerations that support our adoption of the environmentally superior project Alternative 2, despite its significant unavoidable impacts on agricultural and cultural resources.