Hi Jonse my name is James Holt. Most of my experience has been the hard way of failures. I live in Texas where we periodically have years of drought. About three years ago we ended a fifty-year drought that lowered my big pond by about four feet and many of the area lakes were as much as ten feet low. You may not have drought as often where you live but it is something to consider when deciding how deep your pond is going to be unless you have a well to keep it full during drought. Another thing to consider is that metal eventually rusts! Mike Otto said he never uses metal anymore for his ponds because its just a matter of time before it gets a hole in it and drains your pond. Mine got a hole in it and drained my pond after only ten years. The next thing to consider is that the deeper the pond is the clearer the water will tend to be. Its very difficult to keep a shallow body of water from being constantly stirred up by the waves washing up mud from the bottom. However, you do need some shallow water for food production and spawning. Rocks and gravel are really good if you can get them to put in the shallow areas to keep the bottom from being stirred and add habitat. I have a lot of shallow areas in my pond and am constantly adding gypsum each year. There is an entire section on the forum about clearing your pond and anything you can do during construction is easier than afterwards.