Huell visits Edison’s historic Kaweah Hydroelectric Facility on the western slope of the Sierras above Visalia. He interviews Jim Kepner, an Edison carpenter, whose maintenance duties include regularly walking the six-mile long wooden flume that delivers snow-melt waters from the mountains to the electrical generators at the Kaweah facility. Edison’s history dates back more than 130 years and traces it’s beginning to producing electricity with waterpower. Like the Kaweah facility many of the utility’s century-old hydroelectric generating plants are still operating. Huell learns that the continuing success of these facilities is because they hold strong to turn-of-the-century technology and time-tested practices –such as manual inspections. This Flume Walking episode featured a job largely forgotten in a modern company but still provides an essential service in “keeping the lights on” for more than three million customers.