Los Angeles has dumped hundreds of thousands of the shimmering black balls into Ivanhoe Reservoir, one of the city’s last open-air reservoirs.
Los Angeles is protecting its water supply with plastic balls.
The city says it has dumped hundreds of thousands of the shimmering black balls into one of the city’s last open-air reservoirs.
It’s all to prevent a sunlight-fuelled chemical reaction that can harm the water supply.
Workers recently unleashed 400,000 of the hollow, 10-centimetre “shade balls” down a slope to cover the surface of the Ivanhoe Reservoir.
Earlier this year, the Los Angeles Department of Water and Power drained two of its six remaining open-air reservoirs because a rare sunlight-and-chlorine reaction tainted the water with bromate, a cancer-causing chemical.
The amounts were small and didn’t violate federal water regulations, but the water was dumped as a precaution.
The plastic spheres are “a cost effective method of creating shade without elaborate construction, parts, labour or maintenance,” the department said in a statement.