Hydro's mortality is largey attributable to a single, though immensely bad incident, the Chinese Banqiao Dam disaster of 1975. That itself was a consequence of poor engineering, planning, management, response, and an unanticipated weather event (parked typhoon/cold-front dumping > 1,000mm rain in 24h), with most issues being common to any high-profile technical engineering project.
Hydro otherwise is largely safe (there are a few other exceptions, again higghligghting planning, management, response, and institutional integrity, especially in developing regions or periods), problems not specific to the energy-harnessing mechanism) and the Banqiao site is presently home to > 15 millions, rather than being a multi-century technically-induced wildlife park as is the case with other technologies.