Technology development for sustainable use of stormwater using numerical modelling

Runoff estimation is very important for adequate management of stormwater; however runoff assessment is not simple for those catchments where there is a lack of data. Australian Rainfall and Runoff recommended several methods for estimating runoff which are explicitly suitable for particular regions of Australia. Unfortunately there is no regional equation available specifically for Queensland. Moreover, stream gauges in Australian catchments are relatively sparse, and many catchments are crisscrossed by numerous rivers. This study attracted the author’s attention because it was viewed as essential in the Australian context to have a reliable methodology for estimating runoff from ungauged catchments. The main aim of this study is to develop a technology for reusing stormwater for irrigation purposes, especially in an ungauged catchment. This study presents a new approach for stormwater runoff quantification from an ungauged catchment where there is no regional equation available, through developing a hydrologic-hydraulic integrated model, applying Geographical Information Systems (GIS) and numerical modelling techniques. Using the simulated stormwater runoff, the necessary stormwater pond volume is calculated and a typical design of pond is suggested to reuse the stored stormwater for irrigation purposes of a case study area.