It's cooler in the shade

Original post:  Aug 14, 2015

California is suffering through a horrible drought. They are experimenting with a variety of innovative new techniques designed to help reduce water consumption. One of the most interesting programs is helping to protect the main reservoir in Los Angeles.

Roughly 96 million "Shade balls" have been dropped into the lake. These 4-inch plastic balls float to the surface of the reservoir and provide a protective layer over the top of the water. This excerpt from an article in National Geographic helps explain why:

The city says the balls will shade and cool the water, reducing evaporation from the reservoir and making it less susceptible to algae, bacterial growth, and chemical reactions that can produce harmful substances.

Not only is this an innovative solution, it also is quite cost-effective:

The balls cost 36 cents each, for a total of $34.5 million. The utility has been testing the concept since 2008, reporting that shade balls reduce evaporation by 85 to 90 percent. That should equate to saving nearly 300 million gallons a year, enough to provide drinking water for 8,100 people, said Los Angeles City Councilmember Mitchell Englander.

The balls also inhibit microorganism growth, reducing the treatment the water must undergo through other means. That could save the city $250 million over time, said Garcetti.

Made of black polyethylene, shade balls are filled with water so they don’t blow away. A coating resists ultraviolet light and degradation. The manufacturers (XavierC, Artisan Screen Process, and Orange Products) say the balls should last about 25 years.

Here is a link to the full article:  Why Did L.A. Drop 96 Million ‘Shade Balls’ Into Its Water?

Here is a brief video that also explains the process: