Water sensitive urban design in a changing climate: Estimating the performance of WSUD treatment measures under various climate change scenarios

Recent attempts to measure likely impacts of climate change on WSUD measures have focused on performance under a single scenario of adjusted historical rainfall and evaporation. This study adopted an approach whereby a limited number of time series were generated to represent the extremes of a number of projected ranges of climate change scenarios. To support the Mornington Peninsula Shire's Integrated Water Management plan, analysis was undertaken to ensure that future stormwater management strategies were adaptable to a range of possible climate change conditions. Six different scenarios were developed, using stochastic downscaling of historical rainfall and evaporation, to represent predicted climate adjusted conditions under various emissions scenarios. Pollutant generation across the entire municipality and various WSUD measures were modelled under each of climate change scenarios to better understand the sensitivities of both pollutant generation, and resilience of treatment measures including wetlands, raingardens, stormwater harvesting and rainwater tanks to the likely future changes in climate. Results were then used to determine appropriate design considerations for various WSUD measures as well as recommend appropriate climate change adaptations for a number of biological components of these systems such as wetland vegetation.