It all depends on who you ask.
river

Is The Colorado River Becoming Radioactive from Upstream Uranium Mines?

Super Bowl XLII Goes Green with Renewable Energy
Super Bowl XLII is going green this Sunday, using renewable energy from wind, solar and geothermal supplied by the Arizona Salt River Project.

Hydro-Hydraulic Energy Invention
Pakistan inventor Sarfraz Ahmad Khan has been working hard to develop new hydro technologies like this hydro power invention. His latest concept features the run of river active setup of micro hydro power generation blended with basic principals of hydraulics. This concept explores the possibility of transmitting the (collective) mechanical power gained from run-of-river hydro setup by converting it into hydraulic pressure.