Can integrated green spaces and storage facilities absorb the increased risk of flooding due to climate change in developed urban environments?

Impacts of Climate Change on rainfall is shown to increase the risk of flooding in urban areas with high population densities, creating a higher threat to loss of life and damage to property. Integrating stormwater management elements such as storage structures, infiltration and other water sensitive design features into the urban landscape is an increasing trend to adapt to the higher flood threat. Evaluating the effectiveness of these stormwater management features is increasingly more valuable as we try to balance the need for livable space and provide a safe environment within the developed areas and major cities globally. This study looks at two different urban catchments with and without stormwater management features to evaluate how well each catchment can absorb the impacts of climate change on flooding. Results from our analysis shows that sequentially placed storage structures are significantly effective in absorbing the more intense rainfall events expected in a warmer climate. We compare the ratio of total rainfall volume to the volume of flow leaving each of the catchments as an indicator of how well each catchment is able to absorb the impacts of climate change and find that there is approximately a 20-fold decrease in the ratio in the catchment with stormwater management for the future climate conditions. For this study temperature-based scaling is used to account for climate change impacts on rainfall and we use hydrologic and hydraulic modelling to characterize and evaluate the responses of each catchment.