I saw this on Facebook and watched in horrified fascination as this whirlpool sucked down trees and giant chunks of ice.
I went sniffing around to find out what in the world this was, and I found this nice explanation on Doubtful News:
Upon first look at this, I immediately suspected what it might be. Then, other articles noted that comments in the Huffington Post piece may have hit on the same – it’s possible a result of the karstic bedrock underneath. Openings exist in the solutioned bedrock underground. Connected passageways can drain water or loose surface material above. It appears that there has been significant rainfall or ice melt here. Spring is the prime time for sinkholes to form – the ground thaws, water washes surface materials down into openings in the rock below. But why is this water disappearing? Well, the groundwater level would be BELOW the level of the stream in this particular location. There could be many reasons why that happens including low rainfall previously, groundwater pumping from wells or industry, etc. Abundant limestone deposits of the area lend evidence that this may be the case.
Definitely boil your well water. You know, just in case it got sucked down a sinkhole from a nasty muddy lake somewhere.