Walnut Canyon Reservoir

The maintenance and repair work in the reservoir have been completed.

The reservoir is currently at about 75% full and will remain at this level for the most part throughout the year. There may be times during the year where the reservoir will be slightly lowered or raised to accommodate circulation of water in the reservoir. The maintenance and repair work in the reservoir was part of the rehabilitation of the Lenain Water Treatment Plant project. The project is near completion and is anticipated to be completed by Summer 2020. 

Note:  When full the water level in the reservoir is 820 feet = nearly 900 million gallons of water.

Contact Information

Comments or questions may be directed to Robert Hoang, by email or call 714-765-4229. 

If there is an urgent issue or emergency after hours, on weekends or holidays, please call the 24-hour Water System Operations Emergency line at 714-765-4560.

Wide view of Walnut Canyon Reservoir with houses in the distance
Walnut Canyon Reservoir is a 920-million-gallon reservoir that supplies water to homes and businesses in Anaheim’s hill and canyon area that recently has undergone a major rehabilitation. We are very appreciative of the patience and understanding demonstrated by our neighbors during the project's planning, design and construction phases. Now that work has been completed and the project rededicated, we look forward to continuing to work closely with surrounding neighbors as operations continue.  
View of Walnut Canyon Reservoir and bluff with houses at top of bluff
Overhead shot of Walnut Canyon Reservoir
The reservoir receives deliveries of imported, untreated Colorado River Water from the Metropolitan Water District (MWD) of Southern California. Water from the reservoir is then treated at the August F. Lenain Treatment Plant prior to delivery to Anaheim Public Utilities' customers. The reservoir is capable of storing 920 million gallons of imported water, enough to supply the area for 30-45 days in the event of an interruption to imported supplies from MWD. It also offers operational flexibility to avoid imported water peaking charges during summer periods of extended hot weather and provides a valuable resource in helping to contain brush fires.

Quick Facts

  • A working water storage reservoir, it serves as a primary source of water to the Anaheim hill-and-canyon areas; which allows the City to manage short-term, emergency, and seasonal water supply needs.
  • This reservoir also provides the water for helicopter-based firefighting purposes.
  • The Walnut Canyon Reservoir is also historically significant. While the construction crew was restoring the concrete “A” monument, contractors found a handwritten letter inside, which was signed by the original City crew. This letter serves as a testament to the pride that City staff have long had in their work.

May 2020