Impacts of stormwater infiltration on downslope soil moisture and tree water use in ERL

University of Melbourne



The fate of infiltrated water from stormwater infiltration systems is either ignored or simplistically assumed to contribute to recharge and subsequent baseflow. This paper shows that in areas with low permeability, surrounding deep-rooted vegetation such as trees, can play a significant role in the water balance.

Infiltration water balance models should account for evapotranspiration fluxes, with implications also for models which may then look at contributions to groundwater recharge, and for models that consider impacts of evapotranspiration on the local microclimate. This work has important implications for the siting and design of stormwater infiltration systems.

This paper published in ERL (Environmental Research Letters) discusses the merit in designing such systems as broader infiltration precincts, deliberately considering the role and benefits of surrounding vegetation. These precincts will have other important community benefits, such as provision of well-watered greenspace, supporting attempts to mitigate the urban heat island and increase urban biodiversity.