ASK TOM: Low reservoir levels at Hoover Dam

Dear Tom,

We just returned from a visit to Hoover Dam and were amazed at the low water level in Lake Mead. What’s going on?

— The Reilly family, Aurora


Dear Reilly family,

Lake Mead, the huge reservoir impounded behind Hoover Dam (25 miles southeast of Las Vegas), is the largest in the U.S. in terms of water capacity, but the reservoir is in trouble.
Water levels in Lake Mead have been trending downward since the early 1980s, the combined result of increasing demand for water and a stubborn drought. The Colorado River supplies Lake Mead, but subnormal precipitation has reduced river flow rates. The level of Lake Mead is 120 feet lower than its historic high in 1983. Unless the factors change, harsh and disruptive conservation measures will be required within a few years.