I would never wish a backyard pond on anyone, even my worst enemy. Our current house had an in-ground one when we moved in that was roughly 16'x12'. I battled pump failures, clogging constantly, flow levels, herons eating the koi, nutrias....rats and mice love them for the water. I will say the huge bullfrogs where cool when they got fired up in the spring, but that is an acquired audio taste.
One of the best days of my life was when I paid someone to remove the 2 sego palms and dig that damn pond out with a pick axe and shovel. Took me and my son and 6 yards of dirt with a pallet of sod, to repair that other guy's fantasy of a pond. I love looking at the green grass in that area of the yard now.
Probably not what you wanted to hear, but I would look for a fountain, or anything that makes water noise, instead of making lots of problems for yourself and the next guy down the line. Maybe something above ground with a trough type tank, that could easily be hauled off when you or your wife gets tired of it?
Class of '93 - proud Dad of a '22 grad and a '26 student!