Los Angeles has released millions of black "shade balls" into their reservoirs to helps reduce evaporation during drought.
A total of 96,000,000 balls have been released to date and are projected to save the city about 300 million gallons of water annually, according to NPR.
Besides preventing evaporation, the black balls also keep the reservoir clear of dust, pests and animals, unwanted algae growth and toxic chemical reactions that occur when sunlight hits the water's chlorine.
The city believes the balls are a cost-effective way to fight the drought and provide people with clean water, costing 36 cents each, around $34.5 million total, according to USA Today.
Officials say the shade balls are an effective alternative compared to expensive tarps and metal coverings, which can take too long to build.
On Monday, the final 20,000 balls were added to the collection by LA Mayor Eric Garcetti, who commended the Los Angeles Department of Water and Power for their "bold inginuity," according to the Huffington Post.
"In the midst of California's historic drought, it takes bold ingenuity to maximize my goals for water conservation. This effort by LADWP is emblematic of the kind of creative thinking we need to meet those challenges," said Garcetti.
