As many of you know, I spend my summers (and as much time as possible in other seasons) up at our place in southern Vermont (Marlboro, to be precise). And as everyone knows by now, we got creamed by the storm on Sunday. It was an astonishing and awe-inspiring experience to go through — I’ve posted a video that I took during the height of the storm showing the condition of the (one) road that leads from our house, and one of the “little stream” that runs just behind our house, that will give you some idea of what it was like.
As a friend of mine put it, it makes you think a lot about physics. It’s just water, earth, and gravity … a combination of an astonishing amount of rain, steeply sloped hillsides, and ground that was more-or-less completely saturated even before the storm hit. To give you an idea of how much water we’re talking about, take another look at that video of the stream behind our house. This little brook – much too small to even have a name — would, ordinarily, in late August, have a trickle of water in it, at most. The watershed that feeds it covers an area of around 5 square miles — one of thousands of such little watersheds feeding into little streams in southern Vermont (all of which feed larger streams, which feed larger streams, etc.). Five square miles is about 22 billion square inches. Eight inches of rain (which is about what we got) falling on that one little watershed makes for around 175 billion cubic inches (around 100 million cubic feet) of water.
All of that water has to make its way behind our house. If the banks of our little stream are, say, 10 feet apart, and if all of the rain that fell on that watershed had to make it through that space at once – say, in a single column of water, 10 feet in diameter — the column would be around 60 miles high.
It didn’t have to make it through all at once, of course, so it wasn’t 60 miles high … but that gives you the idea. Watching it flow by, tearing up everything in its path, is a sight to see.