Green Roof Stormwater Runoff

In urban areas like.

Green roof stormwater runoff.

Green roofs have a layer of plant material that absorbs water like a sponge. Green roofs are very effective stormwater bmps. Due to the volume reduction actual nutrient loadings from. Green roofs can help to reduce both storm water volume rate of run off entering the drainage system.

Therefore green roofs have an important role to play in the urban realm. A typical extensive green roof of 3 5 inches depth will reduce the volume of runoff by about 55 in central pennsylvania and attenuate the peak runoff rates to the level of the pre development land use. Their major drawback is the initial cost. Green roofs can significantly reduce the amount of rain water that would otherwise run off an impervious roof surface.

They capture water when it rains slowly releasing it through evaporation and plant use.