By Pat Pheifer
Star Tribune
EAGAN, Minn. — Eagan firefighters’ dramatic rescue of two dogs from frigid East Thomas Lake on Thursday morning carries a cautionary tale.
Minnesota ponds and lakes may be icing over, but they’re not safe to walk on — not by a long shot.
Yes, it’s been cold. But it hasn’t been cold enough or for long enough to form a deep enough crust to support the weight of a human or a dog. And especially not a vehicle such as a snowmobile, ATV or car.
The Minnesota Department of Natural Resources says there actually is no such thing as 100 percent safe ice. The DNR website goes on to say, “You can’t judge the strength of ice just by its appearance, age, thickness, temperature, or whether or not the ice is covered with snow. Strength is based on all these factors — plus the depth of water under the ice, size of the water body, water chemistry and currents, the distribution of the load on the ice, and local climatic conditions.”
So how thick does it need to be? Generally speaking, if it’s 2 inches or less, stay off. At least 4 inches is needed for ice fishing and other on-foot activities, 5 inches for a snowmobile or ATV, 8 to 12 inches for a car or small pickup and 12 to 15 inches for medium truck.
Double those amounts if it’s “white ice” or “snow ice,” which is only about half as strong as new, clear ice, the DNR says. And remember, ice does not always form uniformly. It may be a foot thick in one spot and only an inch or two in another just a few feet away.
Luckily for the dogs, they’re home safe with their owners tonight. Their rescue was recorded in a series of photos on the city of Eagan’s Facebook page.