Sea of black plastic balls helps California conserve water

(Image: Gene Blevins/Rex)

What do you get when you tip 96 million black plastic balls into a reservoir? A money-saving system that maintains water quality, according to the Los Angeles Department of Water and Power.

On Monday, the utility company released 20,000 of these balls – each about the size of a grapefruit – into a reservoir in Sylmar, California. It was the final release required to cover the surface of the 12-billion-litre reservoir.

The role of the spheres, nicknamed shade balls, is to block sunlight. Their addition should prevent the loss of about 1.1 billion litres of water that would normally evaporate from the reservoir.

(Image: Gene Blevins/Rex)

The dry spell that has plagued California for the past 15 years is, according to one estimate, the worst drought the area has witnessed in 1200 years. In April, governor Jerry Brown announced that he was imposing a 25 per cent cut in water use across the state to tackle the problem.

The water saved by the ball canopy should provide a yearly supply of drinking water for 8100 people, LA city council member Mitchell Englander said in a statement.

The floating balls should also halt the production of dangerous chemicals that can form as a result of reactions triggered by sunlight in chlorinated water. In addition, they will provide a protective cover for the reservoir, shielding the water from dust and wildlife, while preventing the formation of algae.