Changes

===Variations of Stormwater Tree Trenches===

===Variations of Stormwater Tree Trenches===

[[File:Stormwater Tree Trench low permeability native subsoil with structural soil medium.png|thumb|left|400px|'''Tree Trench with Low Permeability Subsoil''' - This tree trench configuration possess low permeability soil ([[Soil groups]] C or D), and as a result possesses 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 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 (on the right side of the figure), while also allowing for subsequent tree root growth. This structural media allows the trees roots more room to spread under paved surfaces to allow the suitable conditions for urban trees to mature, and cuts down on replacement and maintenance costs of the surrounding sidewalk and road and the removal of dead trees in place of new ones.]]

[[File:Stormwater Tree Trench low permeability native subsoil with structural soil medium.png|thumb|left|400px|'''Tree Trench with Low Permeability Subsoil''' - This tree trench configuration possess low permeability soil ([[Soil groups]] C or D), and as a result possesses 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 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 (on the right side of the figure), while also allowing for subsequent tree root growth. This structural media allows the trees roots more room to spread under paved surfaces to allow the suitable conditions for urban trees to mature, and cuts down on replacement and maintenance costs of the surrounding sidewalk and road and the removal of dead trees in place of new ones.]]

[[File:Stormwater Tree Trench high permeability native subsoil with structural soil medium.png|thumb|right|400px|'''Tree Trench with High Permeability Subsoil''' - This tree trench configuration possess high permeability soil ([[Soil groups]] A or B), and as a result possesses a clean-out stand pipe/clean-out for the underdrain, which is placed higher in the feature as water will infiltrate through the system much quicker. This allows for further infiltration into the system into the underlying native soil below. Once water has percolated through the soil to the perforated underdrain it is then transported out of the feature and back into the storm sewer system. This configuration also includes a monitoring well to monitor water level in the feature below the aggregate line at the bottom of the feature. This feature contains structural soil, similar to the configuration on the left.]]

[[File:Stormwater Tree Trench high permeability native subsoil with structural soil medium.png|thumb|right|400px|'''Tree Trench with High Permeability Subsoil''' - This tree trench configuration possess high permeability soil ([[Soil groups]] A or B), and as a result possesses a clean-out stand pipe/clean-out for the underdrain, which is placed higher in the feature as water will infiltrate through the system much quicker. This allows for further infiltration into the system into the underlying native soil below. Once water has percolated through the soil to the perforated underdrain it is then transported out of the feature and back into the storm sewer system. This configuration also includes a monitoring well to monitor water level in the feature below the aggregate line at the bottom of the feature. This feature contains structural soil, similar to the low permeability configuration.]]

 

[[File:Stormwater Tree Trench high permeability native subsoil with soil cells.png|thumb|center|400px|'''Tree Trench with High Permeability Subsoil, with Soil Cells''' - This tree trench configuration possess high permeability soil, similar to the configuration on the right, but instead of structural soil this tree trench contains soil cells or 'modular soil support systems'.  Soil cells are an alternative to structural soil media and are used adjacent to tree pits to provide room for tree roots to spread out under paved surfaces surrounding the tree trench. The growing media in soil cells typically has higher organic content than structural soils and with a looser structure and higher nutrient content of the soil, these support systems provide the most favourable environment for healthy tree growth in the urban setting.]]

 

 

 

 

 

==Inspection and Maintenance==

==Inspection and Maintenance==