In this case the original building is just a pile of stones with trees growing through the rubble at this point. I can’t see that there is anything of the infrastructure that survived. It is just that if water power worked there once it can somehow work again. I’ve had a bad cold and splitting headache this weekend and didn’t have the energy to pursue the idea further with my son. He is usually ahead of me on sizing things up and I know he’ll get it if I explain it more carefully. With him on my side I might be able to convince my wife.