Bare Hill Pond is looking more bare than usual these days after the annual drawdown drained an extra 7 inches of water this year—over and above the intended 6½-foot reduction. But the pond is likely to restore itself to the preferred depth before the freeze, thereby avoiding potential harm to the wildlife overwintering in the mud.
Pumping was halted last week after personnel from the Department of Public Works and members of the Bare Hill Pond Watershed Management Committee checked the drawdown markers in the pond and saw that too much water had been drained. This came as a surprise, according to the chair of the committee, Bruce Leicher: Normally, the 6½-foot mark is not reached until the end of November. By this week, however, Leicher said the pond “is refilling back towards the 6.5 marker.” And because the pond is spring-fed and several brooks also feed into it, “the normal flow of the spring, and the rain, should take care of the issue” well before the freeze, Leicher said.
And that is good news for the creatures that ride out the winter in the pond’s mud, including frogs, turtles, native mussels, and other species. The timing of the drawdown is important, according to former Conservation Commission member Wendy Sisson, who worked on many drawdown permits over her 20-year tenure. “The water protects the mud and animals from freezing, and protects them from predators like raccoons and great blue herons that gain access when the bottom is exposed,” she said.
Wetland scientist and Harvard resident Bob Douglas concurred, noting that a herpetologist colleague said that too-low levels of water were most harmful midwinter, when frozen mud would prevent turtles and other pond creatures from moving to deeper areas. So assuming the pond refills in the coming weeks, all should be well for the pond dwellers.
Drawdowns began in 2002 as a way to control aquatic nuisance plants by freezing their roots. At first, drawdowns were kept to no more than 3½ feet, as limited by the height of the pond’s outlet, or dam. But in 2006 a new pumping system allowed for more water to be drained into the surrounding wetlands. By 2010, the watershed committee and the Conservation Commission—working with wetlands biologist Wendy Gendron—settled on the ideal depth (6 to 6.5 feet) and timing (October to November) of the annual drawdown.
The pond drawdown leaves a bed of mud where once was water. (Photo by Thomas Kilian)
