Water supply system optimisation - Balancing operating efficiency and water supply security

In addressing the impacts on water resources of persistent drought conditions and population increases, there has been considerable capital expenditure for Melbourne, Australia, into new water supply sources and related infrastructure. This investment includes a new desalination plant.

Planning for efficient use of available water resources is one of Melbourne Water’s key functions. This planning is complex due to uncertain future hydrological conditions and the mix of available water sources ranging from low cost, low reliability catchments through to higher cost, climate independent desalination. In addition to supply and production considerations, energy costs associated with transfer of water through Melbourne’s bulk water supply system also vary depending on time and source used.

With a view to achieving optimal operation of Melbourne’s water supply and bulk transfer infrastructure, Melbourne Water and water systems optimisation specialist Optimatics have developed and implemented a decision support system. A multi-objective genetic algorithm optimisation technique is used to identify a range of optimal supply strategies. Key decision makers subsequently choose the strategy that provides the most appropriate balance between short-term annual operating cost and long-term water supply security through the application of multi-criteria decision analysis (MCDA).