DEC looking for ice-out survey responders
DEC scientist collecting water samples on Molly's Falls Reservoir in Marshfield shortly after ice-out in early spring.
As Vermonters patiently wait for spring, the Department of Environmental Conservation (DEC) invites the public to report when Vermont’s lakes and ponds lose their ice cover. Also known as the “ice-out date,” it marks when lakes or ponds become ice-free from shore to shore.
DEC scientists use ice-out dates to decide when to begin seasonal water quality sampling efforts and better understand how climate change impacts Vermont’s lakes and ponds. By using long-term records on lake ice, it is possible to monitor climate trends across the state and region.
When ice covers lakes, the water below separates into layers based on temperature and density. When the surface ice fully melts in the spring, the heavy cold water sinks, and the water column fully mixes. Water samples collected at this time of mixing show the baseline amount of phosphorus a lake will have available to fuel algae and aquatic plant growth during the spring and summer.
The state has collected information on spring water lake quality from lakes larger than 10 acres since 1977. Over this period, ice-dates are trending earlier across Vermont and New England, which can be a sign of climate change.
Many lake communities around the state hold ice-out contests, usually in the form of a raffle where winners can receive prizes or cash. Some of the more famous and long-running ice-out contest sites include Joe’s Pond in Danville, Lake Iroquois in Hinesburg, and Lake Memphremagog. These contests are an engaging way for lake associations and communities to encourage individuals to observe lakes and ponds throughout the year.
To find spring water quality information go to https://dec.vermont.gov/watershed/lakes-ponds, Links to the Vermont lake score card and lake ice reporting form can be found there as well.
