Brown and Caldwell Begins Work On The Allen-McColloch Pipeline Rehabilitation For Metropolitan Water District Of Southern California

Water delivery pipeline to undergo upgrades to increase system reliability

Brown and Caldwell, a leading environmental engineering and construction firm, was selected by Metropolitan Water District of Southern California (Metropolitan) to provide engineering design services for rehabilitation of the prestressed concrete cylinder pipe (PCCP) portion of the Allen-McColloch Pipeline.

Metropolitan is a regional wholesaler that provides water to 26 member public agencies that, along with their retail providers, serve 19 million people in Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura counties.

Metropolitan’s mission is to provide its service area with adequate and reliable supplies of high-quality water to meet present and future needs in an environmentally and economically responsible way. Through its mission, in 2011 Metropolitan authorized the initiation of a $2.5B PCCP Rehabilitation and Replacement Program, to develop a comprehensive, long-term effort to manage Metropolitan’s PCCP feeders to maintain reliable water deliveries to its member agencies.

The Allen-McColloch Pipeline (AMP) delivers treated water from the Diemer Water Treatment Plant in Yorba Linda to El Toro Reservoir in south Orange County. The length of the feeder is 26 miles. The southern 9-mile portion consists of PCCP, which varies in diameter from 54 to 78 inches, and is the focus of this effort.

As the design consultant, Brown and Caldwell will perform preliminary design and prepare conceptual drawings for the rehabilitation of the pipeline. The work will include relining the pipeline with a seismically resilient liner; replacing existing valves, flow meters, and structures; and other appurtenant work necessary for rehabilitation.

“We are honored to be chosen for this important project,” said Brown and Caldwell Program Director Dave May. “Our committed team looks forward to collaborating with Metropolitan to minimize community and environmental impacts while maximizing the life of existing infrastructure in the most cost-effective and sustainable manner.”

Brown and Caldwell is a nationally recognized leader in large-diameter pipeline rehabilitation, replacement, and design. The firm’s resume includes working with the City of Phoenix to investigate, prioritize, and rehabilitate PCCP segments of the 150-mile aging Val Vista Water Transmission main, the city’s most critical pipeline that supplies 220 million gallons of potable water daily to approximately 60 percent of the city’s population.

The Allen-McColloch Pipeline design phase activities are expected to be completed by July 2023. Upon completion, rehabilitation and construction will be sequenced to minimize impacts to member agency service connections. 

About Brown and Caldwell
Headquartered in Walnut Creek, Calif., Brown and Caldwell is a full-service environmental engineering and construction firm with 52 offices and 1,600+ professionals across North America and the Pacific. For more than 70 years, our creative solutions have helped municipalities, private industry, and government agencies successfully overcome their most challenging water and environmental obstacles. As an employee-owned company, Brown and Caldwell is passionate about exceeding our clients’ expectations and making a difference for our employees, our communities, and our environment. For more information, visit www.brownandcaldwell.com.