Here's another angle...fish production occurs mostly in the top 4 feet of water. Theoretically, water deeper than that is wasted, in terms of fish production. The fact is, water needs to be deeper for other reasons. In arid eastern Colorado, western Kansas, ponds must be deep, or they will dry up. In the north, depth helps fish survive the winter due to ice and snow cover.
The only other reason to build a deep pond is if the terrain dictates it, a gulley or wash. Ponds are designed, including depth, based on the site and goals of the landowner. Be aware of the site, and if a contractor tries to build a pond deeper than it needs to be, he may be looking to make a buck, rather than create a pond in your best interests.
