The Los Angeles Reservoir is covered with over 90 million black plastic balls in the Sylmar area of Los Angeles Wednesday, Aug. 12, 2015. The city has completed a program of covering its open-air reservoirs with floating, 4-inch diameter "shade balls" to protect water quality by blocking sunlight from penetrating the 175-acre surface of the reservoir, preventing chemical reactions that can cause algae blooms and other problems. (AP Photo/Damian Dovarganes), APTOPIX