They stock the place once a year with herring, once they spawn the fry goes over the dam and back down the stream. They come back the next year to spawn. The fish ladder enables the herring to travel around the dam and up to the lake to the lake, I think eels also. Jersey has a law where you cant fish 100 feet around the ladder. The ladder is actually a series of step pools with water flowing out of the lake, the migrating fish jump from step to step to get to the lake, its used like I mentioned to go around Dams.
The place is an old plantation, theres about a dozen old buildings, theres a grist mill, a hog slaughtery, old carriages, old horse stables with old horse harnesses.
If you look at the pictures theres 3 gates that let the water flow to operate the saw, they demonstrate this a couple times a year, I might have to check it out. I was going to take more pictures but the batteries died on me. Next time