Las Vegas obtains 90-percent of their water from Lake Mead. They hafta spend $2-billion for a lower syphon. The Middle of the dam is the Nevada-Arizona border.
Maximum electric power produced by the water turbines: 2.08 gigawatts
Approximate power output: 4 billion KWh per year (i.e. $200 million at $0.05 per kWh)
Source: Wikipedia, Hoover Dam.
Historical Graph of Lake Mead Water Levels Updated every month.
By July 2009, the water is expected to decline below the 1965 level, just 17 feet above the 1,075-foot elevation that would trigger the first shortage declaration under a sweeping interstate pact signed in December 2007. Read more HERE.
The minimum power pool elevation (necessary to generate electricity) is 1050-feet. (The lake bottom is 720-feet.) The elevation, June 2009 = 1095.26 ft. With more water released from Lake Powell power generation will last until 2017 at current rates of consumption.
This link shows (at page 15): Lake Powell dead pool elevation = 3370. In the last 150-days Lake Powell dropped 15 feet, current elevation (January 9, 2010) is 3624 ft., dead pool elevation = 3370; 254 divided by 15 = 16.9 x 150 divided by 365 = 6.9 years until Lake Powell reaches dead pool = 2017.
According to a February, 2008 scientific report, "Lake Mead's water level could drop below the dead storage elevation by 2021 and the reservoir could drop below minimum power pool elevation as early as 2017." Source: "Lake Mead could be dry by 2021".
Tucson uses about 130,000 acre feet of water per year.
The Coachella Valley & Imperial Irrigation Districts use 2,600,000 acre feet of water per year.
Non-Indian agricultural Central Arizona Project (Canal) water uses 364,968 acre-feet per year.
Agriculture consumes 70-percent of the water in Arizona or 4,400,000 acre-feet per year.