[[File:Stormwater Tree Trench low permeability native subsoil with structural soil medium.png|thumb|left|450px|'''Tree Trench with Low Permeability Subsoil''' - This tree trench configuration possess low permeability soil ([[Soil groups]] C or D), along with a clean-out stand pipe for the underdrain, which is placed lower in the feature to allow water to infiltrate into the system and remove contaminants from the road/sidewalk before being taken up by the tree or transported out of the feature and back into the storm sewer system. It also contains structural soil, which is an engineered medium that can be compacted to support sidewalks, while also creating extra space for suitable tree root growth under paved surfaces. This space allows the tree to mature unimpeded and cuts down on replacement costs for tree removal and maintenance costs of the surrounding sidewalk and road.]] | [[File:Stormwater Tree Trench low permeability native subsoil with structural soil medium.png|thumb|left|450px|'''Tree Trench with Low Permeability Subsoil''' - This tree trench configuration possess low permeability soil ([[Soil groups]] C or D), along with a clean-out stand pipe for the underdrain, which is placed lower in the feature to allow water to infiltrate into the system and remove contaminants from the road/sidewalk before being taken up by the tree or transported out of the feature and back into the storm sewer system. It also contains structural soil, which is an engineered medium that can be compacted to support sidewalks, while also creating extra space for suitable tree root growth under paved surfaces. This space allows the tree to mature unimpeded and cuts down on replacement costs for tree removal and maintenance costs of the surrounding sidewalk and road.]] |