Also just found this comment on another video I found.

Recently the "ownership" of the hydro part of the dam was handed over from the feds to a private group of rich people. Before, power generation was secondary. Now they are all about max profits, let er rip, most flow possible thru the generators. This same group got several surrounding coal fired power plants and a nuclear plant taken offline so they could maximize profits from the dam. Since the transfer the water losses have increased regardless of water level.