Green Roof Stormwater Management

Their major drawback is the initial cost.

Green roof stormwater management.

Stormwater management is arguably one of the more beneficial aspects of installing green roofing systems especially in metropolitan areas. Excessive rainfall can result in strains on these systems which can lead to flooding. Green roofs can improve stormwater management. Many of the vegetated roof policies and programs focus on stormwater management benefits.

This course is about the different ways in which green roofs can be utilized as a stormwater best management practice and can supplement existing sewer infrastructure avoiding a number of weather related costs associated with climate change. Current green roof policies tend to be prescriptive based mandating a minimum depth and or composition of green roof growing medium. When it rains runoff flows directly into stormwater systems and nearby waterways. The plants and growing medium of a green roof absorb water that would otherwise become runoff and research indicates that peak flow rates are reduced by 50 percent to 90 percent compared to conventional roofs.

Absorption of runoff into a green roof system will vary between 50 60 and is related to the type of growing medium and plant cover variability. Green roofs will intercept between 15 and 90 of rooftop runoff.