I also love mature trees, and if I had my way, the trees would be on the far edges of my property, to roam in the woods, but not in my yard. I have planted a few trees that will get very large (pin oak, hard maple, and few others) but for the most part the trees near the pond are all smaller types - Red Bud, Dogwood and flowering crabs. I know in time the other trees will provide lots of shade, but I was careful to keep space so none will grow together when mature. I had to deal with hundreds of trees (literally) where I used to live, and it was an every other day thing to blow the leaves to be burned so I would have some grass the following spring. Got to where I hated trees. I love grass. With lots of trees, you have all shade, no grass in the heat of the summer, and cannot have many sun loving plants. It really limits you. Of course, the only shade plants I can have go to the north side of my garage. LOL But, many more sun loving pretty perennials, I think.
I kept my pond lilies on my shelves which in main pond are all about 18", although I have "steps" that are deeper. I did put the lake lily I found last fall in deeper, since I knew it was at least 2' down, it is on the first step, so about 24" down or little less. Found the tuber in the skimmer last night, so the koi must have dug it up. Put larger rock on top of it and sunk the pan again. Bad koi!