Colorado River water is delivered from Lake Havasu by means of a 242-mile long aqueduct. The water originates as snowmelt from the mountainous regions in Utah, Wyoming, and Colorado.

Aquaduct 2State Project water originates in the Sacramento – San Joaquin Delta and is delivered by means of a 441-mile long California Aqueduct.

The District receives a blend of these waters from two treatment plants: Weymouth Filtration Plant in La Verne, supplied by both sources and the Three Valleys Municipal Water District Miramar Plant in Claremont, supplied by the State Water Project.

Through these treatment plants, RWD delivers to its customers an average of 18 million gallons of water a day during the summer and 10 million gallons of water a day during the winter.