How does RWS minimize the crushing possibility of a tree’s roots to the RWS tube?

Tree and shrub roots will find water. They will move toward the RWS tube. However, because it is not filled with soil, the roots will not enter the tube. One option to consider is to fill the tube with pea gravel. The gravel will help dissipate the water and direct it out the sides in a more controlled fashion rather than just filling from the bottom-up. The gravel will also create a firm foundation to the RWS tube, minimizing the possible crushing impact of tree and shrub roots.