There is something deeply strange about Walden Pond. “The pond rises and falls,” Thoreau wrote, “but whether regularly or not, and within what period, nobody knows, though, as usual, many pretend to know.”
What’s weird is that the water level doesn’t seem to vary with local rainfall. It rises and falls for no apparent reason. Henry said “I can remember when it was a foot or two lower, and also when it was at least five feet higher, than when I lived by it.”
The Concord Magazine reprinted a fascinating 1971 article by Eugene Walker, a geologist and local resident. Walker writes, “Tales are told around town of the hole in the bottom of and the stream that comes through it, connected perhaps to a river that is rumored to run underground from somewhere in the White Mountains, perhaps Lake Winnipesaukee, southward to Cape Cod.”
But the truth, Walker explains, is that the pond’s water level varies exactly with the water table in the sand and gravel that surrounds the lake. In other words the lake bed is apparently porous: Continue reading