At first glance, this may appear to be a portal to another world that mysteriously opened up in the middle of a lake, but it’s actually just a spillway. That’s right, “some spillways are designed like an inverted bell so that water can enter all around the perimeter.” Continue reading for a video, more pictures, and additional information.

Video

In areas where the surface of the reservoir may freeze, bell-mouth spillways are normally fitted with ice-breaking arrangements to prevent the spillway from becoming ice-bound. Chaffey Dam, located near Tamworth, New South Wales in Australia has a classic example of an inverted-bell spillway. It was the first one of its kind in Australia.

Pictures

[Sources 1 | 2]