Green Roof Infiltration

Use practices that do not require infiltration.

Green roof infiltration.

Impervious roof areas that direct runoff onto the green roof cannot exceed 50 of the green roof area which is equivalent to a maximum hydraulic impervious runoff loading ratio of 0 5 1. Rainwater harvesting green roofs vegetated swales and. Integrating a green roof into a historic building rehabilitation project may appear to be an easy solution to reducing the urban heat island effect improving storm water management and improving the energy efficiency and sustainability of the building. Green roofs are unique in that they have the ability to capture and retain a volume depth of rain from each rainstorm.

Integrate practices into your treatment drains to mitigate stormwater impacts including. The minimum thickness of the green roof growing medium must be calculated as follows where the impervious roof area to green roof area ratio is less. This captured water is then evapotranspired back to the atmosphere through the green roof vegetation. Green roofs can help reduce energy costsfor a building by acting as another layer of insulation between the inside and outside of the roof.

In fact a green roof replicates the natural landscape allowing water to infiltrate the vegetation substrates and engineered drainage layers of the green roof.