The Cleaner, Greener, More Affordable Water Cooler for Los Angeles

At the start of the 19th Century, Los Angeles was still just a western outpost. But the next hundred years would turn this sleepy town into a burgeoning metropolis, thanks to the discovery of oil, flourishing farmland, and the construction of the Southern and Santa Fe rail lines. As the city grew, crude systems of dams, water wheels, and ditches connected to the Los Angeles River couldn’t keep up with demands. So, Los Angelenos looked to the mountains in the north as a water source. Planners purchased land and water rights in the Owens Valley, which had an abundance of freshwater runoff from the eastern Sierra Mountains.

The task of bringing the water from Owens Valley to Los Angeles fell on the shoulders of a newly appointed water chief, William Mulholland (as in Mulholland Drive). Construction of the LA Aqueduct started in 1908 and took 5 years to complete. It involved the demolition of 5 miles of granite, the construction of 3 reservoirs, and communications lines stretching across 200 miles.

When finished, the Aqueduct flowed across 9 deep canyons, 61 miles of open canals, and 142 tunnels. At the 1913 dedication of the Aqueduct, Mullholland famously proclaimed, “There it is, take it!” as the water gushed down the Aqueduct to Los Angeles. Save for an extension in the 1940s and an additional pipeline in the 1970s, the Los Angeles Aqueduct has remained mostly unchanged since the water first traveled from the Sierra Mountains.

Today, Los Angeles represents the largest municipal utility in the nation. Los Angeles tap water comes from 3 primary sources.  Seventy-two percent of water comes from the Los Angeles Aqueduct before treatment at the Los Angeles Aqueduct Filtration Plant. The city supplies 21% of water from the Metropolitan Water District (MWD). The remaining amount is sourced from local groundwater and recycled water.

The city plans to build 2 facilities to further improve Los Angeles water quality, including the Los Angeles Reservoir Ultraviolet (UV) Disinfection Facility, which will rely on a multi-barrier disinfection approach. The Headworks Reservoir West will store and supply 60 million additional gallons of Los Angeles drinking water. According to the recent Los Angeles Water Quality Report, tap water meets current state and federal standards. However, the agency can’t ensure all water remains clear of contaminants.