Factors that predict clogging through porous pavements

Porous pavements are one of many Water Sensitive Urban Design (WSUD) technologies that are widely used to manage stormwater runoff. They are easily retrofitted and are effective in improving water quality and hydrology, but are prone to clogging. Despite being a major determinant in the lifespan of porous pavements, there is a dearth of information on the physical clogging processes through these systems. The aim of this study was to develop a fundamental understanding of the main physical processes that govern clogging, and ultimately develop a simple model that predicts clogging through porous pavements over their lifespan. This paper presents findings from two laboratory experiments that were conducted over 3 years at Monash University on three commonly used porous pavements. The key variables that were hypothesised to influence clogging were pavement design, flow dynamics as well as drying conditions. The pavements investigated in this study were observed to clog at various times, with the exception of one, which showed no signs of clogging despite receiving 25 years of simulated Brisbane, Australia rainfall. Systems that were simulated under varied inflow conditions, along with drying sequences were found to double the lifespan of systems simulated under a constant continuous flow without drying.