Use of green roofs to solve storm water issues at the basin scale – Study in the Hauts-de-Seine County (France)

Abstract

At the building scale, green roof has demonstrated a positive impact on urban runoff (decrease in the peak discharge and runoff volume). This work aims to study if similar impacts can be observed at a basin scale. It is particularly focused on the possibility to solve some operational issues caused by storm water.

For this purpose, a methodology has been proposed. It combines: a method to estimate the maximum roof area that can be covered by green roof, called green roofing potential, and an urban rainfall-runoff model able to simulate the hydrological behaviour of green roof.

This methodology was applied to two urban catchments, one affected by flooding and the other one by combined sewage overflow. The results show that green roof can reduce the frequency and the magnitude of such problems depending on the covered roof surface. Combined with other infrastructures, they represent an interesting solution for urban water management.

Keywords:

• flooding
• green roof
• hydrological modelling
• scale study
• sewage network
• SWMM

Acknowledgements

The authors would like to thank the Water Direction of the Haut-de-Seine County, especially Christian Roux and Christophe Lehoucq, for providing geographical and hydrometeorological data and expertise.

Additional information

Funding

This work has been supported by the French C2D2 framework programme through the TVGEP project.