Millions of Shade Balls

Millions Of 'Shade Balls' Protect LA's Water During Drought

Los Angeles can't make it rain, but it can shield its precious water with "shade balls" -- 96 million of them to be exact.

For months, the Los Angeles Department of Water and Power has been releasing the black plastic balls to float on the surface of the 175-acre Los Angeles Reservoir in a massive drought relief project. The final 20,000 went in on Monday, with some assistance from LA Mayor Eric Garcetti.

By deflecting UV rays, the opaque spheres are expected to protect more than 300 million gallons of water from evaporating in Southern California's harsh sunlight every year.

LADWP was the first utility company to use this technology to protect water, according to a press release from Garcetti.

"In the midst of California's historic drought, it takes bold ingenuity to maximize my goals for water conservation," the mayor said. "This effort by LADWP is emblematic of the kind of creative thinking we need to meet those challenges."

Besides slowing evaporation, the shade balls prevent sunlight from triggering a dangerous reaction between bromite, a chemical occurring naturally in groundwater, and the chlorine used to disinfect the water. When sunlight interacts with those two chemicals, Plastic News explains, the suspected carcinogen bromate is formed.

The shade balls also deter wildlife from contaminating the reservoir, shield the water from wind-blow dust and discourage algae from forming on the water's surface.

City officials hailed the shade balls as very cost-effective. They run just 36 cents a piece, The Guardian noted, and require no additional construction or maintenance -- except to be rotated occasionally.

"Shade balls are a great example of how engineering meets common sense," LADWP general manager Marcie Edwards said in Garcetti's press release. "... 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 help us continue to deliver the best drinking water to our customers."

Watching the shade balls cascade into LA's largest reservoir is also completely mesmerizing.

But the shade ball technology doesn't mean Los Angelenos can ease off their water conservation efforts. After a snowpack measure in the Sierra Nevada mountains in April revealed levels at a record low 6 percent of the long-term average for that time of the year, Gov. Jerry Brown (D) announced California's first-ever statewide mandatory water cutbacks, and those remain in effect.

Money could soon become available for bigger projects. Last month, California's two Democratic senators, Dianne Feinstein and Barbara Boxer, introduced emergency drought legislation in Congress, aimed at supporting other water projects in their dry state and helping poor rural communities that face severe water shortages.

Source: Huffington Post

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1 Comment

1. The City of Los Angeles has just finished spending $34.5 million on 96 million 'Shade Balls' which are 4 inch black HDPE balls that form a floating cover on liquid surfaces. The City and their manufacturer are claiming that 300 million gallons of water will be saved from evaporation each year but they present absolutely no data to verify those claims.

   The City experiences roughly 70-100 inches of surface water loss annually due to evaporation. 'Shade Balls', being black HDPE and a partial cover, retain 80% more thermal energy and conform to S. Assouline's findings from 2010 on the efficiency of partial covers. Those findings cite decades of evaporation studies that clearly explain how evaporation works and why temperature, or thermal energy, is the most important variable for predicting actual evaporation rates. 'Shade Balls' were not designed with an understanding of how evaporation works. 'Shade Balls' were designed to be cheap; black HDPE is one of the least expensive and most commonly used resins in plastics manufacturing.

   It seems that Mayor Eric Garcetti and the LADWP are satisfied with their lack of basic evaporation understanding because of reassurances from their vendors XavierC LLC, Microdyne Plastics, Orange Products, and ECC LLC that their "tested" black balls "come with the added benefit of reducing evaporation off the reservoir surfaces by 85 to 90 percent." But they don't. Additionally, if 'Shade Balls' suppress 300 million gallons from evaporating as is claimed, then Los Angeles must also be evaporating over 14 ft. from reservoir surfaces and experiencing average temperatures of over 90 degrees Fahrenheit annually (U.S. Climate Data says it's closer to 63.8 degrees). But they aren't.

   With 70-100 inches of evaporation, a white floating ball cover could suppress between 126 million and 183 million gallons of water from evaporating each year with 90% efficiency. Black 'Shade Balls' are only 50-70% efficient due to their high solar energy retention which increases the evaporative energy of the hyperbolic diffusion streamlines of water vapor.

   Los Angeles' 'Shade Balls' will only prevent a maximum of 141 million gallons from evaporating each year but may only suppress as little as 70 million gallons from evaporating at higher temperatures.

   Those are the facts, backed by published science, publicly available on the internet.

   What if I told you a white cover was on the market for almost half the cost and twice the performance (www.hydroorb.com)? What if Los Angeles did their homework on this project (they'd save $15.3 million and save more water).

   Do your research. Share this information.

   Let me know if I can provide any citations.