The city of Montpelier used treated wastewater to mitigate an ice jam Monday that developed on the Winooski River between the Taylor Street and Bailey Avenue bridges, according to a press release.
“The City has implemented our treated effluent ice melting system and will leave it running overnight as a precautionary measure,” Department of Public Works director, Kurt Motyka, wrote via email.
This system discharges treated wastewater into the Winooski River from the city’s wastewater treatment facility located near downtown behind a building used by the state’s Department of Liquor and Lottery, according to the release. The method opens a channel for the river water to flow through by melting the ice.
At 11 a.m. on Monday, a Winooski River gauge in the area was at 7 feet, shy of the 11 foot action stage that would trigger preparations for potential flooding. By 1:15 p.m., the river reached its peak of 9.63 feet, according to Motyka. Half an hour later, the level had dropped to 7.24 feet and most of the ice had cleared through the city, Motyka said.
The city’s emergency management team closely monitored the river’s water levels. Motyka also wrote that barricades were staged in critical areas surrounding the ice jam, but the department did not need to close any nearby roads or sidewalks. Officials also had a long-reach excavator nearby in the event that ice accumulated near the I-89 overpass. Neither the barricades nor the excavator were needed as of 3 p.m.
Ice jams can occur in rivers and streams during warm weather when ice that developed during a period of cold temperatures begins to melt, causing chunks to break off. Those ice pieces can collect, creating a barrier to the water flow. The jam can then cause water levels to rise upstream and downstream from the jam, creating the potential for flooding.
Montpelier has experienced ice jams before, including one that caused flooding and significant damage in 1992.
Read the story on VTDigger here: Montpelier officials use treated wastewater to shrink Winooski River ice jam.