A large amount of damage can be caused to drainage systems by tree roots damaging and causing blockages in the drains. This is a natural issue to deal with as trees and plants tend to grow towards water sources (this is called hydrotropism) and thrive in damp areas, including drains where water is present. If roots get into the drains and aren't dealt with, they will grow over time, causing damage to the pipes, collapsed drains and also blockages.