A new initiative by the Los Angeles Department of Water and Power (LADWP) has taken a surprisingly low-tech approach to water conservation, by covering the LA Reservoir in 96 million black "shade balls." It's an attempt to combat water loss through evaporation, and to heighten water quality.

California's water shortages are now believed to be so severe that the state would now require 20 inches (51 cm) of rainfall – that's the equivalent of an entire year's precipitation – to remedy the crippling rain debt.

In this context, the LA reservoir has become an even more vital resource, spanning an impressive 175 acres (71 hectares), and holding roughly 3.3 billion US gallons (12.5 billion liters) of water – enough to support the entire city of Los Angeles for up to three weeks.

Each shade balls costs 36 cents, with the entire project amounting to US$34.5 million. Whilst this may sound like a lot of money to turn LA's largest reservoir into a massive watery ball pit, other water-saving alternatives would have proven far more costly to implement.

Another option that had been under consideration would have seen the reservoir separated into two distinct basins with the use of a bisecting dam, and protected with a floating cover, at the much greater cost of $300 million.

The unusual strategy represents a significant cost savings of around $250 million, and could prevent the loss of up to 300 million US gallons (1.14 billion liters) of water to evaporation. Simultaneously the shade balls will increasing water purity by preventing contamination via wildlife and dust, as well as reducing sunlight-triggered chemical reactions.

It is estimated that the sheer quantity of water saved under the initiative will be sufficient to provide drinking water to around 8,100 LA residents for an entire year. Scroll down for a video showing the release of 20,000 shade balls into the LA Reservoir.

Source: LADWP

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