FILE - In this July 28, 2014 file photo, lightning strikes over Lake Mead near Hoover Dam at the Lake Mead National Recreation Area in Arizona. Water levels at Lake Mead and Lake Powell are dropping to dangerous levels, reflecting the Colorado River’s worsening “structural deficit,” scientists said. Scientists from the Colorado River Research Group said Lake Powell has declined because of extra water releases flowing into Lake Mead, the Arizona Republic reported Aug. 28, 2018. John Locher, File AP Photo