Multicriteria Analysis to Select an Optimal Operating Option for a Water Grid

Water supply systems are diversifying and expanding in response to climate pressures and population growth. However, these water grids present challenges for the water supply manager in identifying optimal operating options for the short term. This study demonstrates the final step in a framework to address these challenges, multicriteria analysis, using a case study based on the South East Queensland water grid. A shortlist of nine water grid operating options have been identified, which are optimal in terms of minimizing total operational cost, maximizing water security, and minimizing spills from reservoirs, over a 5-year period. This study assesses the performance of each of these nine operating options against a wider set of 18 criteria reflecting cost, supply reliability, environmental flow, water quality, reservoir spill, and water security concerns. The weighted summation multicriteria analysis technique is used to combine and rank performance of the nine operating options against the 18 criteria. An operating option is selected that performs best on average across the 18 criteria and four scenarios of preference weights. This operating option comprises a set of operating rules that can form the basis of a short-term optimal annual operating plan. (C) 2017 American Society of Civil Engineers.