Leidesdorff-Coloma Substation Project

SMUD proposes upgrading the existing Leidesdorff-Coloma Substation, which will primarily involve replacing aging equipment to enhance the reliability and efficiency of the substation. To complete the substation upgrade, the substation will be deenergized and all the existing equipment will be removed including the grounding grid which is buried approximately 18-inches deep. The only exception is the subtransmission tower, located in the eastern portion of the substation, which will remain and to which only minor upgrades are required. Prior to replacing the substation equipment, the substation will be graded and leveled by importing soil and gravel to raise the northern half of the substation approximately 5 feet. The driveways within the substation will be replaced, and new substation equipment will be installed including the transformers, switch gear, spill and stormwater containment, and the underground grounding grid. The heights of the new substation structures will be comparable in height to the existing structures in the existing substation. The footprint of the approximately 1-acre substation will not increase; although, the configuration of the fencing will slightly change to accommodate the design. The new substation fence around the perimeter of the substation will consist of 10-foot chain link fence topped by barbed wire with larger entrances for both gates along Leidesdorff Street. An additional component of the project consists of trimming or removing vegetation within a 27-foot strip of SMUD-owned property located adjacent to the substation’s western boundary and installing a new non-conductive fence along the western property line. If the vegetation is removed rather trimmed, the area will be graveled and used as a secondary maintenance access route to the substation and SMUD’s property located north of the substation. Construction is anticipated to start in the fall of 2026, and the substation will be reenergized in spring 2027.