The worst drought in California history is leading to some creative ideas for saving water. The city of Los Angeles turned its primary reservoir into a giant ball pit.
What they did was dump 96 million 4-inch plastic balls into the 175-acre reservoir, covering its surface. The balls shade and cool the water, reducing evaporation and limiting algae, the growth of bacteria, and many chemical reactions.
The balls are made of black polyethylene and are filled with water so they don’t blow away. They are coated to resist ultraviolet light and degradation and are expected to last about 25 years. At 36 cents a piece, the city spent $34 million on the plastic balls.
It is a good investment. The balls reduce evaporation by 85 to 90%, equating to a savings of 300 million gallons of water a year – enough to supply drinking water for over 8,000 people. By inhibiting microorganism growth, the balls mean that less water treatment is needed, which could save the city $250 million over time.
Shade balls have now been used in a number of places, but Los Angeles is the first to use them on such a large scale. The idea came from “bird balls” used to discourage birds from spending time in ponds alongside airport runways. The shade balls are one of the ways that the city has cut its water use by 15% over the past two years. Meeting the challenges of the sustained drought in California calls for creative thinking. The giant ball pit in L.A. is a good example.
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Why Did L.A. Drop 96 Million ‘Shade Balls’ Into Its Water?
Photo, posted August 10, 2015, courtesy of Eric Garcetti via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.