Many old towns are built near waterfalls, because the falling water was once used to turn water wheels.

What you'll need: a small ball, about the size of a soccer ball; a bath towel; a chair on wheels, like a desk chair; a furniture-free area; some of your favorite dance music; a tall glass of water!

We could make electricity using water wheels so as not to kill fish and I am sure a million more intelligent ways but no one is interested in making a small plants.