On 24/11/2019 17:56, Clive Arthur wrote:
Or a hose and a water wheel.

That's the way to do it. Heath Robinson would be proud of you...

recirculating pump on the gate post so there's a continuous stream of water.

Water wheel and generator on the gate so it intercepts the stream when
the gate is closed.

We'll all want it in the DIY FAQ... probably under humour

Andy