The other day with my waterfall I tried to explain about sluice gates, well this set at an old mill should be much easier to explain.
The river is flowing from the left and disappears under my signature on the right. To get the mill working, the 4 sluice gates are closed and the river is forced to go under the mill in the background and turn the waterwheel which makes the machinery work - SIMPLES.
Best viewed with the magnify button above the picture.
Lovely shot, your sluice gates work the same as our dam gates do. By opening or closing for the water, one is able to generate power by water. It helped when you explained how it works. I got it, light bulb went off for me. LOL
FAV