Designing Porous and Permeable Pavements for Stormwater Harvesting and Reuse

Water is a scarce resource in Australia and the conservation and re-use of stormwater runoff is often important to supplement the municipal water supply. The quality of the runoff is also important to ensure that it can be reused, or discharged to a location where it will not have negative impacts. Pavements are ubiquitous in our urban environment and consequently they have become an intrinsic and seldom thought-about part of life. However, for developers and local authorities who have to address stormwater flooding and water quality issues, they are very much at the forefront of the planning process. This is because impervious surfaces such as pavements have such a major impact on water quality and on the health of natural ecosystems. In response, Water Sensitive Urban Design (WSUD) strategies, such as permeable and porous pavements, have been developed to reduce the environmental footprint of new growth. Porous and permeable pavements are becoming more prevalent as a stormwater management tool. Porous and permeable paving provide an ability to infiltrate stormwater on site, or harvest stormwater for fit-for-purpose reuse using geomembrane sealed subsurface ‘tanks’. This paper describes experiments conducted at the University of South Australia to investigate the reuse potential of water harvested using porous and permeable pavements. The experiments focused on identifying and quantifying the water quality processes occurring in the storage mechanism. This paper also describes the new PERMPAVE software program which has been developed as part of the same research program