Preventing reservoir evaporation during droughts with floating balls may not help conserve water overall, due to the water needed to make the balls.
During droughts, communities may rely on water stored in reservoirs. However, significant amounts of water can evaporate from the surface of the reservoir.
Amid California’s latest drought, which lasted from 2011-2017, 96 million ‘shade balls’ were deployed on the Los Angeles reservoir. These floating, black plastic balls cover the water surface to prevent evaporation.
However, a new study published today in Nature Sustainabilityshows that producing the balls probably used more water elsewhere than was saved during their deployment – which could have knock-on environmental impacts.
Read more at Imperial College London
Image: Deployment of shade balls at the LA Reservoir. CREDIT: Eric Garcetti