This presentation is based on research by Susan Bendel that focused on the interaction of roots from Eucalyptus leucoxylon, Lophostemon confertus, Callistemon salignus, Allocasuarina littoralis, Acer palmatum and Pyrus calleryana with stormwater pipes. The pipes had cracks of 0.04mm, 0.66mm and 1.48mm cut along their upper surfaces. There was no significant difference in the mass of roots in the pipes for the two larger crack widths. A second experiment using Eucalyptus leucoxylon, Melaleuca ericifolia, Ficus macrophylla and Salix fragilis found that a synthetic stormwater solution significantly increased growth compared with potable water. In this experiment tree roots were able to grow through holes of 0.5 mm diameter.