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The Metropolitan Water District of Southern California
Mills Treatment Plant

The Henry J. Mills Treatment Plant is located in the city of Riverside, and sits near the Box Springs foothills at an elevation of 1,650 feet, the highest of Metropolitan's five treatment plants.


The plant supplies State Water Project treated water, via gravity flow, to the Eastern and Western Municipal Water districts of Riverside County.


Mills was completed in 1978 and has been upgraded from a treatment capacity of 150 to 220 million gallons per day. It is Metropolitan's smallest treatment facility.


The endangered Stephen's kangaroo rat lives outside the Mills plant's perimeter. Knee-high walls have been built to encourage the nocturnal rodent to live and nest within protected areas.


The plant is named after Henry J. "Hank" Mills, who capped a 41-year Metropolitan career by becoming general manager in 1967, a post he held for almost five years before retirement.


Henry J. Mills
Treatment Plant

550 E. Alessandro Blvd.
Riverside, CA 92508

(909) 780-1511