Los Angeles has been blackballed.
The city has completed a program of covering open-air reservoirs with floating "shade balls" to protect water quality.
City officials this week dumped the last 20,000 of 96 million black balls into the Los Angeles Reservoir in Sylmar, 25 miles northwest of downtown.
The 4-inch-diameter plastic balls block sunlight from penetrating the 175-acre surface of the reservoir.
That prevents chemical reactions that can cause algae blooms and other problems, allowing the Department of Water and Power to meet U.S. Environmental Protection Agency water-quality requirements.
They have the added perk of aiding with the ravages of the drought, and are expected to keep about 300 million gallons annually from evaporating.
The 36-cent balls also will help prevent evaporation of 300 million gallons of water annually from the 3.3 billion-gallon reservoir, the DWP said.
The city began using shade balls in 2008, and they now also cover the Upper Stone, Elysian and Ivanhoe reservoirs.
Tens of thousands of plastic balls were dumped intentionally into the biggest reservoir in Los Angeles to combat California’s drought. The balls that poured in were the last of 96 million balls, completing an evaporation barrier on the reservoir. John Blackstone reports on how they could help the state bounce back from its water emergency.