http://www.usbr.gov/lc/region/g4000/...le.cfm?GAGE=30
Strange things afoot at Hoover. By my estimation, they should be producing about 14,400 MWH per day with a slow increase into the heat of summer as electrical demand rises for running air conditioners.
http://www.eenews.net/stories/1060002129
If Lake mead drops below 1050 feet, Hoover Dam was originally designed to be producing 0 MWH, although they can retrofit it to work all the way down to 950 feet at very low electrical output, theoretically at least.
Much of the prosperity of the west coast for the last 70 years was due to the availability of cheap energy from Hoover.
If I had to guess, they either changed intakes - or they shutdown their ultra-efficient generators (ultra efficient generators only work when there is enough water pressure, and no surface air pocket "foam" mixed in with the water)