There was no spillway or other overflow (like the little hole in the top of your sink) in Taum Sauk. It was a kidney-shaped reservoir with a
big fucking hole in the bottom which was used to fill the reservoir and through which the water flowed back out through the same turbines used to pump it full.
There is
another opening of some kind in the junction of the wall and bottom, but I have no idea what it is for.
Level was apparently completely controlled by an electronic sensing system (perhaps related to
this thingamajig?