Have you ever heard of the Devil’s Kettle Falls? The falls sit above Lake Superior about a mile inland on the Brule River at Judge C.R. Magney State Park, Minnesota. As the river makes it way to the lake, it gets split in two by a rocky knob located just above the falls. While the east half tumbles down 50 feet in normal waterfall fashion, the west half disappears into a very large pothole and is never seen again.
For years people have been trying to solve the mystery of the disappearing stream of water by throwing ping-pong balls, logs and dyes, but none of them seemed to give a clue as to where the water was going. Jeff Green, a researcher from the Minnesota Department of Natural Resources (DNR), thinks that he has finally found the answer to this puzzling geological phenomenon.
Green and his friend Calvin Alexander, a retired University of Minnesota professor decided the river’s flow should be measured first to determine if the water does, in fact, vanish from the river. Green and his team of hydrologists used stream gauging equipment to measure the volume of water flowing above the falls and below.
The results showed that the water flowed at 123 cubic feet per second above Devil’s Kettle and was 121 cubic feet per second about 500 feet downstream. Green explains that in the world of stream gauging, the numbers are nearly identical. This proves that the water is resurging in the stream below and not disappearing into some underground cavern.
In the fall of 2017, when the water flow is low, Green and his friend are planning to pour a biodegradable dye into the Kettle to determine the precise location where the water rejoins the river.