A few links for background and details. TVA (justifiably) gets all the infrastructure geek attention but this is baby is quite impressive in its own right: http://www.wunderground.com/blog/JeffMasters/comment.html?en...
(I found the nature of the '73 flood's damage to the system in above to be very interesting.)
This promises to be a good read -- haven't read it yet myself: http://www.newyorker.com/archive/1987/02/23/1987_02_23_039_T...