The Lake Hemet Municipal Water District in California was able to take advantage of the unique geographic location of its recently completed Theodore H. Eggen Filtration Plant by incorporating a gravity flow system into the process train. As a result, total power requirements are less than 20 hp. The automated 6 million gallon per day plant requires only one hour of supervision each day. The article discusses the background to the plant design, as well as the treatment process, treatment equipment, treatment methods, filtration, and hydraulic profile of the essentially gravity flow operation.