Identification of Optimal Water Supply Portfolios for a Major City

摘要

Integrated urban water management (IUWM) considering alternative water supply options is attracting increasing attention from water resources managers due to its efficiency and flexibility in addressing water scarcity problems. Adelaide, the capital of South Australia, is an example of a city where water supply security has come under increasing pressure due to population growth, climate variability, and climate change, as well as emerging environmental needs. In order to address this issue, the South Australian government has committed to implementing IUWM principles through a number of actions including an initiative to integrate alternative water source options for metropolitan Adelaide, called the Urban Water Blueprint. This study is part of the optimal water resources mix (OWRM) project, which was initiated by the South Australian government through the Goyder Institute for Water Research to inform the development of the Urban Water Blueprint. In this study, a multiobjective optimization-based IUWM approach is applied to Adelaide to identify its optimal water supply portfolios and, in turn, to inform policy aimed at prioritizing the development of different types of potential water resources. These sources include traditional water sources, such as surface water from reservoirs and rivers, as well as alternative water sources, such as desalinated sea water, harvested stormwater, and reclaimed wastewater. In addition to the traditional objectives of minimizing economic cost and energy consumption (or the associated greenhouse gas emissions) and maximizing reliability, the impact of stormwater and wastewater discharge on receiving waters is also considered. The results demonstrate that for Adelaide, the optimal mix of sources contains water from traditional surface water sources, harvested stormwater, and reclaimed wastewater. Traditional surface water is a low-cost and low-energy source; reclaimed wastewater is likely to have significant environmental benefits in the long term. (C) 2017 American Society of Civil Engineers.