Their major drawback is the initial cost.
Green roof stormwater management.
Green roofs are very effective stormwater bmps.
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.
Green roofs will intercept between 15 and 90 of rooftop runoff.
Stormwater management is arguably one of the more beneficial aspects of installing green roofing systems especially in metropolitan areas.
Many of the vegetated roof policies and programs focus on stormwater management benefits.
Variation in absorption rates can be as great as 50 based on differences in temperature wind evapotranspiration rates and plant uptake.
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.
Excessive rainfall can result in strains on these systems which can lead to flooding.
When it rains runoff flows directly into stormwater systems and nearby waterways.
Green roofs can improve stormwater management.