I saw this happen on Pennsylvania's Leheigh River in the late early 70's. This river doesn't have any electrical generation, the dam that was built by the Army Corp of Engineers in the 60's (it was completed in 1966) was supposedly for "flood control". The Leheigh flows through a gorge (canyon for those in the west) its who length from the dam downstream to it confluence with the Delaware River near Easton, PA. Supposedly this "flood control dam" would allow the Corp to hold back water to reduce the chance of flooding in all the towns along its banks and to reduce the chance for flooding in Philadelphia as well.
The Francis Walter Flood Control Project releases its water from the top 30 feet of the pool, and during exteded hot, summer weather, the water temps get into the low 70's. Resulting in a once marvelous trout fishery being decimated (PA Fish Cmmission developed its infamous 'palomino rainbow trout, which tolerates temps to the mid 70's without lethality to keep a trout fishery in the river).
Anyway I digressed. During the early 70's the white water enthusiats decided that taking a trip through the Leheigh Gorge from the hamlet of White Haven, WA to the slightly larger hamplet of Jim Thorpe, PA (about 25 river miles) would be an ideal thing to do several times during the summer. You guessed it, the Army Corp of Engineers was pressured by several PA Congressmen to have large releases of water during the summer so this "important recreational use of the river" could be enjoyed when air and water temps would be less likely to produce hypothermia. The sportmen in the area felt betrayed, and wrote many letters, etc. The end result, the "recreational, white-water boaters got what they wanted. The fishing got even worse as a result.
I sincerely hope you will be able to stop this from happening.