Prediction of the Drinking Water Supply Under Climate Change Using System Dynamics Approach: A Case Study for the Hinze Dam, Australia

Over the last decade, the potential impacts of climate change on streamflow regimes have gained considerable attention. Such changes can potentially affect regional water resource availability and water supply. Additionally, demands for drinking water supply will likely change in the future as a consequence of climate change and population growth. This study attempts to investigate the changes in Hinze Dam’s (Nerang River catchment, Southeast Queensland, Australia) operation and ability to meet drinking water demands under climate change scenarios. A conceptual rainfall-runoff model (Mike 11 NAM) was employed to estimate the runoff generated from future precipitation and evaporation rates predicted by the CESM-CAM5 model – one of the recommended climate models for Eastern Australia (EA). After generating the runoff data, a system dynamics approach was implemented to build a reservoir model for simulating Hinze Dam operation. In order to investigate potential changes in drinking water demand under climate change, as a consequence of population growth, five scenarios were considered, which respectively assumed a 1%, 2%, 3%, 4%, and 5% accumulative increase in the annual water demand rate. Three performance criteria, namely, reliability, resiliency, and vulnerability, were used to analyse the potential impacts of population growth and climate change on the ability of the reservoir to meet the annual water demand. The results were compared to predict to what extent population growth and climate change can have an impact on Hinze Dam’s water supply capability. The outcomes of this study contribute to more efficient decision making, and policy improvement for the purpose of mitigating drinking water shortage in EA.