Australia’s increasing population, natural climate variability and susceptibility to projected climate change impacts are placing ever-greater pressures on existing water infrastructure. This infrastructure, that generally uses low energy approaches such as capture and storage of runoff in elevated catchments and local capture and storage of rainwater in tanks, is no longer sufficient to supply the increasing volumes of water demanded.

Water suppliers have therefore been diversifying risks through utilising energy intensive climate-independent solutions. To date, water suppliers have investigated various options and implemented alternative sources, such as desalination, groundwater extraction, pipeline distributions and recycling schemes. These sources however require technologies that are more advanced and/or require greater operational energy costs. It is clear that current water utilities attempts at addressing emerging water problems in Australia, comes at a price of higher operational energy requirements.

Assessing the water-energy nexus, the relationship and interactions between water and energy, is therefore crucial for the water industry to reduce operational energy costs and design water and energy systems for synergistic benefit. Further, in an environment in which energy issues are becoming increasingly important, this link means that water service providers need to be aware of the energy impacts of infrastructure they implement as well as consider the changing cost of energy.

This literature review addresses the water-energy nexus through assessing current energy requirements and associated operational energy costs for various water treatment technologies. Additionally, a critical review of various water supply options currently being investigated or implemented by water utilities is presented from an energy perspective. Finally, system management approaches as well as other alternative low-energy water supply or saving options are addressed.