Yes, long inactive hydro dams are being taken down. These are the kind that incorporate none of the modern ecological improvements (fish ladders, aeration, etc), where the reservoir is not used for drinking water. Usually the reservoir water is chock full of excess nitrogen and other pollutants. These are usually defunct small-scale hydro plants that were formerly associated with an old-school river-side factory - the kind that now stand vacant or are converted into high end condos nationwide. Or are you talking about hydro dams getting taken down because the water usage was too great to sustain the reservoir because we've decided that the desert is a great place for agriculture?

But that's right, fuck the fish and aquatic life, we should invest massive capital on restarting decades dead microhydro plants.