Integration of Stormwater Harvesting and Baseflow Restoration Measures to Restore Catchment Hydrology
(2010 – current)
It is well known that urbanisation has dramatically modified the water cycle in urban catchments. Specifically, a major consequence of an increase in impervious areas in a catchment is the alteration of runoff characteristics, which has highly detrimental effects on urban streams: thus changes in both water quality and flow regime have been identified as major stressors of stream ecosystems. Water Sensitive Urban Design has been developed for several decades to address this issue, including a wide variety of infiltration-based and retention-based systems. The overarching aim is to keep as much water as possible in the catchment and possibly reusing part of it to alleviate water stress in urban environments.
However, research has often focused on the behaviour of individual WSUD systems and little is known on the consequences of large scale implementation of these systems. While it is often claimed that infiltration systems may restore the decreased baseflow of nearby streams, there is little evidence of the actual impact of these systems. With this prospect, the aim of Perrine’s PhD is twofold. The experimental part is looking at local factors influencing the water budget of an infiltration system (e.g. surrounding vegetation, local topography). This study, based on data from several raingardens in Mount Evelyn (Victoria, Australia), aims at estimating the consequent groundwater recharge and comparing it with that of the natural – ‘pre-developed’ – catchment (based on a series of baseflow indicators). In a second stage a conceptual model will be built on these findings to evaluate the consequences of WSUD implementation at the catchment scale: spatial distribution of the various systems as well as their individual characteristics will be looked at to assess their potential to restore flow regimes back to their natural state.
This research will feed into the Little Stringybark Creek project, within the Ecosystem Dynamics Program, which aims to protect and restore a stream (Little Stringybark Creek) through stormwater harvesting, integrated with stormwater filtration and infiltration techniques. See the Little Stringybark Creek Section of this website for more information on this research program.