"I am curious as to why it would be better for a WI pond to be deeper than 10-14'?"
It prevents less chance of winterkill assuming the pond is not aerated. Basically the short version is the deeper a pond is the more water volume it has in relation to its surface area; surface to volume ratio. The larger volume of water holds more dissolved oxygen compared to the bottom surface area which means the longer the DO lasts during snow cover. The bottom surface has a majority of the dead organic materials which consume the biggest portion of the DO the fastest. This is why shallow ponds with less water volume on top of the bottom muck frequently have fish winterkill because they more quickly 'run' out of DO during winter.
In other words Dissolved Oxygen loss in ponds and lakes generally and gradually proceeds from the bottom toward the surface. So when there is more distance or depth (volume)above the bottom the longer it takes for the oxygen loss to reach the surface.
The rate of DO loss usually depends on the conditions of each pond or lake with the more eutrophic and enriched being the fastest DO loss.
Also the deeper a pond is the longer it takes for it to fill in with muck / organics and become a swamp, marsh or wetlands.
Last edited by Bill Cody; 03/27/15 10:40 AM.
