On Aug. 12, the city of Los Angeles in California covered its reservoir with about 96 million black plastic balls, in an effort to combat the state’s record-breaking drought. These “shade balls” are expected to prevent contamination and evaporation of what becomes residents’ drinking water.
The balls’ surfaces are covered with black carbon, which is known to absorb UV rays. Experts say that this will help block sunlight from the water. As a result, certain chemical reactions that could lead to the formation of algae or some human carcinogens will be prevented and the water will stay clean. Additionally, the city will save about 300 million gallons of water per year from evaporating.
Meanwhile, others are concerned about the amount of heat the balls will need to be able to withstand over time. Because the balls act as a huge thermal blanket, they can create the perfect conditions for bacteria to grow. Amid all the mixed opinions, the city is desperately hoping that its measure will help bring an end to the water crisis.