California’s water problem is severe. Despite 2016 seeing a distinct improvement in precipitation over previous years, to almost average levels in many areas, much of the state is in extreme drought. As well as ordering mandatory water reductions, the state has also been looking to other solutions.

“Shade balls,” the 4-inch wide black plastic balls pictured above blanketing Los Angeles Reservoir, have been touted as one of those solutions. But they’re not. The primary purpose of the release, which went viral last year, was to obey Federal rules on covering drinking water. The Los Angeles Department of Water and Power (LADWP) had previously used the balls in smaller reservoirs, and in the case of the Los Angeles Reservoir, says the balls helped the department save more than $250 million over installing a more permanent cover.