LA is dumping millions of small plastic balls into its reservoir to tackle the drought | ScienceAlert

Wow.

This is one of those stories that doesn’t make a lot of sense until you’ve heard the science behind it: earlier this week the mayor of LA Eric Garcetti helped to dump 20,000 small black plastic balls into the city’s reservoir. It marks the final phase of a the innovative project, in which a total of 96 million balls have been poured into the 175-acre man-made lake.

The reason? These ‘shade balls’, as they’re known, are actually very effective at keeping water clean and protecting it from evaporation – an issue that those living in Los Angeles and the rest of California are only too aware of right now. Each ball is weighed down with a little water, they’re cheap (costing just 36 cents per unit), and they can last for 10 years before they need to be replaced.