We want to build a pond, but we are unsure of where to start. We have a relatively small backyard, but we want a comparatively large pond. We were thinking about building a circular pond, with the deepest parts being 3 feet deep, and the circle is cut into two kidney shapes, separated by an island with a bench in the middle and a shallow strip of water connecting the two sides around the island with a stepping path to cross to the island. Will water just one or two inches deep be enough to separate the two sides? We were wondering if on one side we could keep native fish and on one side ornamental goldfish. This brings me to my next question, if we wanted to attract wildlife and make the fish population on the native side relatively self-sufficient, what type of fish should we include? We were looking into sunfish, but how many and is that a good idea? We are looking for plants and animals native to north Texas. Thank you, we need help on how to make the island, the two sides, the organisms, and just how a pond works in general, so if someone could also explain oxygenation, filtration, etc. that would be great. We are looking at using a corner of our backyard, is 13 by 13 feet big enough for the whole pond?