Haiwee Power Plant Penstock Replacement
Owner: Los Angeles Dept. of Water and Power
Lead Design Firm: Golder Associates
General Contractor: Barnard Construction Co.
To produce hydropower and provide clean drinking water for Los Angeles, the Haiwee Power Plant Penstock project replaced 9,420 linear ft of carbon steel-riveted penstock. Originally installed in the early 1900s, the gravity-fed penstock carries water from the South Haiwee Dam to the Haiwee Power Plant and is part of a Los Angeles aqueduct that brings drinking water 233 miles from the Sierra Nevada to the city. A previously collapsed section of penstock was restored in the 1980s but was distorted due to numerous longitudinal creases and folds.
Crews replaced the penstock with 84-in.-dia, bell-and-spigot, fiberglass-reinforced polymer pipe. The work took place in a remote area of high desert and entailed cutting nearly 2,000 linear ft of penstock into sections before removing it and abating more than 1,800 linear ft of those sections because of asbestos in their exterior coating.
More than 170 oversize truckloads of 84-in.-dia pipe, most of it in sections measuring 60 ft long or greater, were transported 1,100 to 2,050 miles from manufacturing plants in Washington and Alabama.
The project also installed fire hydrants, a penstock drain line and an updated cathodic protection system.
The project’s biologically and culturally sensitive location required daily meetings and continual communication with biological, cultural and archaeological monitors, all of them on site full time during construction to ensure that resources were protected.