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Sunset Complex Project


California is in the middle of another drought with water supplies reaching historically low levels. With water supplies becoming scarce, Pasadena Water and Power (PWP) is looking to address aging water infrastructure and improving local resiliency.

The Sunset Reservoir is one of 14 reservoirs that serve a critical role in the City’s drinking water system. Approximately 25% of the City’s water demand is served by the Sunset Reservoirs, which have been in service for over 125 plus years and are in need of replacing. The proposed “Sunset Complex Project” improves system reliability to ensure that all of PWP’s water customers have access to safe drinking water. This project will also improve the aesthetics of the Sunset Complex site.

Existing Sunset Complex Aerial View
Existing Sunset Complex Aerial View


The original Sunset Reservoirs were constructed in the late 1800s and consisted of two open earth embankment structures lined with cobble stones and mortar. These reservoirs were lined with concrete in the 1890s and covered with wood framed roofs and corrugated metal decks by the 1920s. Around the 1930s, the reservoirs walls and roofs were raised four feet to increase the original storage capacity from 10.2 million gallons to 15.5 million gallons. In 1947, the Glorieta Pump House was constructed to convey potable water to Sheldon Reservoir.

Historic Aerial view of sunset complex
Historic Aerial (1937, UCLA Department of Geography, Benjamin and Gladys Thomas Air Photo Archives, Fairchild Aerial Surveys Collection)


The Sunset Complex Project will replace the existing reservoirs with two circular concrete storage reservoirs that will be designed to current seismic standards. A new groundwater treatment plant will consists of ion exchange to remove perchlorate; liquid phase granular activated carbon to remove volatile organic compounds; and a disinfection system. This treatment system will allow PWP to utilize more of the City’s groundwater supply. In addition, the project will include emergency power generators to keep the Complex in operation in the event of a power outage. The Sunset Complex site will also continue to serve the parking needs of the City’s employees. The Complex is surrounded by City residents so visual appeal incorporates new fencing and landscaping.

A map of the Sunset Complex Project site

Community Outreach

PWP staff has held community outreach meetings informing the neighborhood of the project, and will continue to plan additional meetings as the project progresses. Currently, the Sunset Complex Project is in the environmental review process and design phase.

Environmental Impact Report

An Environmental Impact Report (EIR) is being prepared for this project. A draft Initial Study has been posted, and is available for public review until May 9, 2022. Please direct all written comments via email and/or postal service to:

Mr. Michael Lin, P.E
Pasadena Water and Power
150 S. Los Robles Ave., Suite 200
Pasadena, CA 91101

Additional Resources

Sunset Complex Project Environmental Notice

CEQA Scoping Meeting Presentation - April 21, 2022

Sunset Complex Project Community Meeting Presentation - March 24, 2022


If you have any additional questions about the project, please contact Michael Lin, P.E. at