 kind of planted in a location where it doesn't have enough room for the roots to grow and the tree starts to die back as a result of it, you're probably not going to be able to create more space for the roots to grow. So you're in kind of a no-win situation in that regard. When there is serious flooding, water erodes soil around the roots, making the tree's root plate unstable. Leaning trees are an imminent fall hazard and should be removed.