3. Project Description

The Valley-Rainbow Project would provide an interconnection between SDG&E's existing 230 kV transmission system and Southern California Edison Company's (SCE) existing 500 kV transmission system. The proposed project is located in northern San Diego County and southwestern Riverside County. The proposed project consists of:

1) construction of a new 500/230/69 kV substation located in Rainbow in northern San Diego County;

2) construction of approximately 31 miles of 500 kV single-circuit overhead transmission line from SCE's existing Valley Substation to the proposed Rainbow substation; and

3) modification of the existing Valley Substation to accommodate the new 500 kV transmission line.

In addition, the proposed project would add an additional 230 kV circuit to the existing Talega-Escondido 230 kV transmission line, rebuild 7.7 miles of 69 kV transmission line between the existing Pala and Lilac Substations, and add voltage support systems to the existing Mission, Miguel, and Sycamore Canyon Substations.

We refer to this plan of service as the "proposed project" or "Valley-Rainbow Project" throughout this decision. When discussing the proposed 500 kV line between Valley Substation and the proposed Rainbow Substation, we refer to the "Valley-Rainbow 500 kV line."