MacKay Sposito provided engineering services for a substation project in San Luis Obispo County, California. The client was experiencing flooding at a large transmission substation and smaller distribution substation. MacKay Sposito assessed the existing conditions, including evaluating conveyance of stormwater during large flow events.
MacKay Sposito utilized LiDAR data and HEC-RAS to model inundation areas during specified storm events and to determine water surface elevations around the substation sites. A memorandum was then prepared summarizing the existing site conditions and water surface elevations during 10, 25, 50, and 100-year storm events. Recommended improvements to eliminate flooding were also included, consisting of drainage channel improvements, utilizing pumps, and construction of a wall to prevent water from flowing into the substation.