Rainfall simulation study of the impact of unsealed roads in Cardinia Shire

Cardinia Shire Council, the City of Casey, and Mornington Peninsula Shire Council, with funding from the EPA Victoria as part of the Victorian Stormwater Action Program (VSAP), undertook an investigation of the impact of unsealed roads on stormwater quality. The aim of the project was to identify ways to minimise the impact of sediment runoff from the unsealed road network on the receiving waters of Western Port Bay and its tributaries by reviewing and investigating best practice road maintenance measures. Various road treatments were trialled to examine how road-surfacing techniques on unsealed roads affect sediment runoff and storm water quality. Rainfall simulation was employed as an effective method to facilitate the rapid completion of the project. This paper reports on the experimental set-up, issues involved in the experimental method, and some of the results on the effectiveness of different road treatments.