Green Roof Stormwater Management

Many of the vegetated roof policies and programs focus on stormwater management benefits.

Green roof stormwater management.

Variation in absorption rates can be as great as 50 based on differences in temperature wind evapotranspiration rates and plant uptake. Green roofs can improve stormwater management. Their major drawback is the initial cost. Current green roof policies tend to be prescriptive based mandating a minimum depth and or composition of green roof growing medium.

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. Excessive rainfall can result in strains on these systems which can lead to flooding. Green roofs will intercept between 15 and 90 of rooftop runoff. Green roofs are very effective stormwater bmps.

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.