The DWP is replacing an aging water pipe through Griffith Park and the zoo is expanding its nearby parking lot.
The project calls for installing 11,200 feet of 96-inch-diameter welded steel pipe through Griffith Park, to address concerns about low water pressure and also to comply with federally mandated water quality regulations.
The DWP was willing to suspend construction to accommodate the holiday light festival, but LaBonge said that would jeopardize the project's target completion date of November 2011.
The mile-long light festival features displays celebrating Los Angeles area sights and landmarks. In the past, people could walk, bike or drive through to see it.
CNS contributed to this report.