Lake Mead's water level has three times fallen below the drought level (1125 feet above sea level).[4] From 1953 to 1956, the water level fell from 1,200 to 1,085 feet (370 to 331 m). From 1963 to 1965, the water level fell from 1,205 to 1,090 feet (367 to 330 m). Since 2000 through 2008, the water level has dropped from 1215 to 1095. In 2009 the water level rose slightly due to cool winter temperatures and rainfall.
In June 2010, the lake was at 39 percent of its capacity,[5] and on Nov. 30, 2010 it reached 1,081.94 ft (329.78 m), setting a new record monthly low.[6] Arrangements are underway to pipe water from elsewhere in Nevada by 2011, but since the primary raw water intake at Lake Mead could become inoperable as soon as 2010 based on current drought and user projections, Las Vegas could suffer crippling water shortages in the interim.[7]
http://en.wikipedia.org/wiki/Lake_Mead