(NECN: Jack Thurston, Montpelier, Vt.) - The National Weather Service has warned of an elevated risk of spring flooding in Vermont. The melting of a deep snow pack, which is one to two feet in many places, and three to four feet at higher elevations, could contribute to the potential flooding situation, said National Weather Service meteorologist Jason Neilson. "We need the gradual warm-up and no big rain events," he added.
A slow, gradual warm-up would reduce the chances of a rush of water from melting snow over still-frozen ground, and would reduce the threat of ice jams, Neilson explained. "We don't want a big warm-up too quickly, even though it would feel nice to have 40s, 50s and even higher," he said. "But the gradual warm-up, for flooding purposes, would work a lot better than like, going to 70s or 80s for next week."
Chief Robert Gowans of the Montpelier, Vt. Fire Dept. said he fears thick ice on the Winooski River could clog up around river bends and bridge abutments as the ice breaks apart, blocking the river's normal flow and causing it to jump its banks and gush into the downtown. "We're taking it very seriously," Gowans said of the flood risk. "The next two to three weeks are the prime time."
Gowans is monitoring flood gauges on the Winooski River, as well as data from the National Weather Service, in order to supply city leaders with daily flood risk assessments. Right now, no flooding is imminent and the river is several feet from flood stage, Gowans said. "We're at the 25th of March, and have had no melting yet," he noted. "It could happen very fast."
"I don't want to go through it again," said Montpelier business owner Fred Wilber, describing the March 1992 flood that filled the city's downtown with frigid water and dealt his music store, Buch Spieler, serious losses.
Wilber said he is mindful of the risk of a rapid warm-up causing widespread melting and putting the river at risk of clogs from ice chunks. "I'm ready for a warm-up myself, but not if it means flooding," he said.
Gowans said Montpelier is using effluent that has been treated at the city's wastewater plant to help reduce the impact of ice jams. The clean water is 40 degrees and is being discharged into the river, under a permit from the Vt. Agency of Natural Resources, Gowans explained. That has helped clear a channel in the ice on the river's surface that Gowans hopes will keep water flowing, should ice jams cause a backup.