I would like to create a privacy screening and need a tree about 15' high and the same or larger spread for an area that has standing water. We have clay soil in our Zone 4 Steamboat Springs, CO area. The only tree I can find that may be suitable is the 'Golden Idol' dwarf curly willow. Other than the curly branches, it doesn't have much appeal throughout the seasons. I love the Staghorn Sumac but I don't think it will tolerate the water. Anyone have any ideas? Thanks!