They don't need to be cut down because of pipes. The pipes can be replaced around the trees by cutting out roots, and relocating the pipes, if necessary. Once the cement is damaged, what's the point of cutting down the tree? You need to replace the cement anyway. Even if you have a shallow-rooted tree, it will take 20 years before it heaves the new cement enough to need replacement. Short-sighted people cut down street trees, using flimsy excuses. Two months ago I allowed someone to cut down a rear yard tree because it was cracking the wall of his building. His building is illegally too close to my tree (there needs to be a setback), and I allowed him to cut it down, on the condition that he replace my tree. I still don't have a new tree. Trees are so nice, and it is more work not to have a tree than to have one (they protect from direct sun, for example, making your house more comfortable in summer; they absorb rainwater, cutting back on runoff; they provide wildlife habitat; they absorb carbon dioxide and clean the air, etc.)