DWP to Reline Water Pipelines

The Los Angeles Department of Water and Power has announced two pipeline rehabilitation projects to improve water quality for Valley residents in North Hollywood, Woodland Hills and Tarzana.

On Aug. 31, the department will begin a cement mortar lining project on Vanowen Street from Coldwater Canyon Boulevard to Morella Avenue in North Hollywood, said Michael Grahek, contract administrator for the DWP’s pipeline rehabilitation section.

In October, the department will start a similar project in residential areas bordered by Winnetka Avenue and Reseda Boulevard, south of Ventura Boulevard in Woodland Hills and Tarzana, Grahek said.

Cement mortar lining, in which a buildup called tuberculation is removed from the inside of the pipes and replaced by a protective coating of cement mortar, improves water quality, he said.


“Typically, the pipes are made of unlined cast iron and we’ve had water quality complaints from those areas,” he said.

In addition to cement lining, the DWP will slip-line or reline existing water pipelines with high-density polyethylene pipe on Coldwater Canyon from Ventura to Burbank boulevards, and on Vanowen from Morella Avenue to Troost Avenue, Grahek said.

The North Hollywood rehabilitation project, including the slip-lining, is estimated to cost $1.4 million, he said, while the West Valley project is estimated to cost between $1.2 million and $1.5 million.

“The pipeline rehabilitation techniques that the DWP currently employs typically saves between 60% to 70% on conventional dig-and-replace methods with minimal disruptions to the surrounding communities,” he said.


The North Hollywood project is due to be completed by mid-December and the West Valley project by July 1999, Grahek said. He added that the DWP will notify residents by mail prior to construction.

Residents who experience water or power outages during construction may call the DWP hotline at (800) DIAL-DWP.