What is the difference between lakes and ponds?

It all depends on whom you ask.

In Minnesota, which has close to 13,000 lakes that need to be supervised and regulated, the State Department of Natural Resources defines a lake as any body of water at least ten acres in area, and anything smaller being a pond.

Ecologists and botanists look at the effect wave action has on shoreline vegetation. Where waves can regularly grow to a size large enough to limit such vegetation the body of water is considered to be a lake. Where the body of water is too small to permit such waves from forming the plot of water would be called a pond.

Liminologists, those who study bodies of inland water, look more to the effect that the depth of water has on life forms. Where the depth is great enough to permit a stratification of water into upper and lower zones that are separated by a third zone (the thermocline) the body of water is usually considered to be a lake. Any body of water too shallow to permit such stratification is considered to be a pond. And, neither is dependent on size considerations.