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Drought-hit California turns to innovative shade balls solution

orSome 96M shade balls have been released onto the surface of the Los Angeles Reservoir, in a move that will save more than 300M gallons of water lost each year through evaporation.

The project, described by the Los Angeles Department of Water and Power (LADWP) general manager Marcie Edwards as ‘engineering meets common sense’ cost US$34.5M (£22M) but aims to save £160M compared to alternative measures.

In total 96M balls – costing £0.23 each – have been released on the 175-acre reservoir that holds 3.3bn gallons. The small, black plastic balls protect water quality by preventing sunlight-triggered chemical reactions, deterring birds and other wildlife, and protecting water from rain and wind-blown dust.

The alternative measures considered included splitting the reservoir into two with a bisecting dam and installing two floating covers.

california, mayor, water

Source: LA Mayor Eric Garcetti

Mayor Eric Garcetti releases the final 20,000 shade balls onto the surface of the Los Angeles Reservoir.

LADWP general manager Marcie Edwards said: “Shade balls are a great example of how engineering meets common sense. Our water system has significantly changed since William Mulholland built it more than 100 years ago. As we make updates, we are mindful to be wise and practical with our investments. Shade balls are an affordable and effective way to comply with regulations, and helps us continue to deliver the best drinking water to our customers.”

LA mayor Eric Garcetti added: “In the midst of California’s historic drought, it takes bold ingenuity to maximize my goals for water conservation. This effort by LADWP is emblematic of the kind of the creative thinking we need to meet those challenges. Together, we’ve led the charge to cut our city’s water usage by 13%, and today we complete an infrastructure investment that saves our ratepayers millions and protects a vital source of drinking water for years to come.”

Readers' comments (3)

  • Would it not have been better to have white shade balls as they would reflect the light and do not absorb heat which the black balls surely will. If the black balls absorb heat they may well increase the temperature of the surface resulting in evaporation through the voids between the balls.

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  • Barry Walton

    And protecting a surface water reservoir from rain? Whatever next?
    As reported in the Economist last week, according to the US Geological Survey Californians use 181 (US) gallons per head per day. That is what needs blackballed.

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  • Here's the reason why the balls are black

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