Good Question: What Makes A Lake, A Lake?
MINNEAPOLIS (WCCO) — In the land of 10,000 lakes, the question of what makes a lake a lake is a timeless one.
How big does a body of water have to be? How deep? And aren’t some of these so-called lakes pushing it?
From the largest lake within our border — Red Lake’s 288,800 acres — to one of the smallest, Spoon Lake’s six acres in Maplewood, our lakes are very different from each other.
“There are no threshold numbers in terms of size or depth,” said Glen Yakel, a retired Department of Natural Resources waters supervisor.
The definition of a lake involves size, but that’s not the only consideration, he said.
“A lake would be sufficiently large and deep to create wave action that would sweep at least part of the shore free of vegetation,” he said.
So it’s not just the size of the water, it’s the motion of the ocean, if you will.
By comparison, a pond is a basin surrounded by tall vegetation. Often there is no shoreline.
A lake may have an inlet and/or an outlet stream. Or a lake may be completely enclosed, or landlocked. Generally, a lake is an area of open, relatively deep water that is large enough to produce a wave-swept shore.
“There are government agencies that have threshold numbers, those are for regulatory purposes,” Yakel said.
So when Minnesota counts its lakes — all 11,842 of them — it’s only counting lakes larger than 10 acres, or about the equivalent of 30 suburban residential yards.
“I believe Wisconsin uses a one acre cell size, which is a football field with no end zones,” Yakel said.
That’s why Wisconsin claims to have around 15,000 lakes — more than Minnesota. But the reality is, if Minnesota lowered its threshold down to two and a half acres, that would add another 10,000 lakes, Yakel said.
Minnesota Lakes Facts and Figures (from the MN DNR):
Total Area Covered by Lakes and Rivers (deep water):
Largest lakes (entire lake within borders of Minnesota):
Red Lake (both “Upper” and “Lower”) – 288,800 acres
Mille Lacs Lake – 132,516 acres
Leech Lake – 111,527 acres
Lake Winnibigoshish – 58,544 acres
Lake Vermilion – 40,557 acres
Lake Kabetogama – 25,760 acres
Mud Lake (Marshall County) – 23,700 acres
Cass Lake – 15,596
Lake Minnetonka – 14,004 acres
Otter Tail Lake – 13,725 acres
Counties with no natural lakes:
Mower, Olmsted, Pipestone, Rock