In a series of deployments begun last June and completed this week at a cost of $34.5M, the City of Los Angeles dumped 96 million black, polyethylene “shade balls” into its reservoirs to conserve water, prevent algae growth, and protect against wildlife incursions. Following the video, US News and World Report picks up the story.
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.
Los Angeles conducted a similar deployment in 2008 to prevent the toxic mixing of sunlight, bromide and chorine in its Indian Lake Reservoir, the Los Angeles Times reported at the time.