California has been having water problems for a while now, and the drought this summer has been particularly bad. One way to lessen the blow of that drought is to protect reservoir water from evaporating, thus prolonging supplies and reducing the need to tap into natural reserves. Of course, that isn’t an easy task, but Sydney Chase had an idea that seems to have worked out pretty well.

That idea is a product called “shade balls.” Social media cheekiness aside, the idea has a lot of merit. The balls themselves are black spheres four inches in diameter, and made of polyethylene. They float on top of the water and, in large enough numbers, block the sun from reaching that water, allowing it to stay water and not evaporate. In total, 96 million of these spheres were dumped into California reservoirs, covering the surfaces and protecting the water form evaporation.

Chase founded XavierC to manufacture the balls, though she also worked with two other companies, Artisan Screen Process and Orange Products, to fill the massive order for the Los Angeles Department of Water and power. XavierC was founded especially to make the shade balls, but Chase also wanted to provide jobs for disabled veterans, and the company is even named after one such veteran.

The Environmental Protection Agency has been urging local water managers to find ways to protect their reservoirs from evaporation, especially in drought-prone areas like the Southwest. These shade balls, which are technically called conservation balls, are a novel way of doing that. They’re also perfectly safe, as the material they are constructed of is certified safe for contact with drinking water, and they are designed not to degrade over time. If this plan works out for reservoirs in Los Angeles, we should probably expect to see shade balls floating in reservoirs across the country.