[freebeard]

The creek is running clear and I've amused myself 'testing' submerged 'sand dunes', various rocks, cans, and bottles in the flow....

Nikola Tesla invented the bladeless turbine when he was ~4 years old, with a disk on an axle over a creek.

Then there is Viktor Schauberger and his Implosion Energy.

Viktor Schauberger, Living Water and Lessons from Nature
https://www.water-for-health.co.uk/o...s-from-nature/
Viktor Schauberger (30th June 1885 - 25th September 1958) was a forester from Austria. He had a gift of perceiving natural energies and understanding how nature operated. Instead of going to university, Schauberger took off into the forest, living in an area undisturbed by man and learning directly from the world around him.

Viktor Schauberger: Ecological Flood Prevention
https://www.facts-are-facts.com/arti...ure-for-nature
This was one of Schauberger's key principals: "You don't regulate a river from the outside in, but from the centre, from the flowing water itself." Managing the river in this way avoids situations where the riverbank is torn away on one side while banks of gravel and silt form on the other, which in the worst case have to be dug out.