Lenain Water Treatment Plant


Anaheim Public Utilities is rehabilitating the Lenain Water Treatment Plant. This plant treats water that is imported from the Colorado River and stored in Anaheim’s Walnut Canyon Reservoir. The treated water from the plant serves residences and businesses throughout Anaheim, providing water supply and meeting maximum day water demands. The plant includes the water treatment facilities, an operation and control center, and a water quality lab. The plant was last upgraded in 1996 and improvements are needed to replace aging infrastructure and improve safety and security. 

This project will replace outdated equipment such as valves, electrical controls, and pumps in the treatment plant as well as valves in Walnut Canyon Reservoir, retrofit facility structures to meet current seismic codes, install a back-up power generator, improve the access road, install surveillance cameras, construct new pipelines, and replace the pavement on the boat ramp. The project will also include construction of a new storage building adjacent to Walnut Canyon Reservoir to house the controls for valves and chemical feed systems.

Project Updates:

Work done so far:

  • Valve replacement and other maintenance work in Walnut Canyon Reservoir was completed in early June 2019 and the reservoir was refilled immediately.  Currently the reservoir is filled at about 75% capacity.  The reservoir will remain at this level and will be increased as necessary based on water demand and other operating factors.
  • The new influent and effluent pipelines have been installed.
  • The new reservoir outlet structure has been completed.
  • Rehabilitation of the boat ramp is completed.
  • Rehabilitation of the flow control facility near the water treatment plant has been completed.
  • Rehabilitation work on the treatment facilities is completed. The plant is back in service.
  • New access road is nearing completion.
  • Rehabilitation of the flow control structure is nearing completion.
  • Rehabilitation work inside the operations building has started.
  • Installation of new generator has started.
  • Installation of new bypass pipeline has started.

Upcoming work within the plant site: 

  • Installation of educational exhibits throughout the Plant.
  • New landscaping around the Plant.

Upcoming work at and near Walnut Canyon Reservoir: 

  • Install informational displays near the reservoir.

Completion date: May 2020

If you have questions or comments regarding the Lenain Water Treatment Plant Rehabilitation project, please contact Robert Hoang, Project Manager and Community Liaison, at 714.765.4229 or e-mail rhoang@anaheim.net.
lenain map