Drought is gripping a number of regions across the globe, from a one in five hundred year drying event in Europe which is impacting municipal water supplies, crop yields and power station operation, through to historic reductions in river flows in China, Africa and parts of the United States. The increased severity and frequency of these events, often punctuated by devastating floods, is now recognised as a being a consequence of human-induced climate change, emphasising the importance of mitigation and adaptation to this global challenge, and highlighting the linkage between these issues.
Water planners in government and in utilities are searching for new strategies to respond and adapt to these challenges, and ways to increase the resilience of water systems and the communities that they serve. It is also becoming clear that it usually not possible to ‘build a way out’ of this problem, by increasing water storages, or increasing water supply capacity to meet a worst possible drought, as the costs become prohibitive to keep adding supply to meet previously improbable droughts. The response needs to include management options, and an attention to demand-side or water efficiency options, as well as contingency options that can be quickly implemented as droughts worsen. This includes an investment in best practice water saving measures, equipment, practices, processes and enabling elements.
What does this mean? Water efficiency options include widespread use of water loss reduction methods and pressure management in the reticulation system; standards and labelling for new appliances and fixtures; retrofitting existing homes and businesses to bring them up to best practice water efficiency. It also means smart metering and pricing, and customer feedback to reinforce the value of water, and to reflect the costs, including the scarcity cost, of suppling water in a carbon-constrained world. Time and again the experience from implementing these measures in communities around the world shows that water efficiency is the largest, the cheapest and the quickest way to meet an emerging supply-demand gap. Many water efficiency measures can cost less than 1 EUR per m3, compared to new supply options which can be more than twice this cost, especially as new supply options are increasingly expensive, with limited surface water storage options, longer inter-catchment transfers, deeper groundwater or energy intensive desalination.
Recycling of wastewater or urban stormwater can also be used to substitute for potable supplies, and benefit from the reducing cost of small-scale wastewater treatment systems. These systems can be built closer to the wastewater source and the water demand, helping to reduce the cost of water and wastewater reticulation. Reduced water demand can help reduce the capital and operating cost of wastewater treatment and recycling systems and reduce energy costs and greenhouse emissions as well.
To enable all this to happen, and to happen quickly, requires changes to the way that water is managed and governed – that is, the institutional arrangements. Water efficiency options, as described above, need to be assessed and costed alongside supply options on an equal footing, on an economic basis, comparing the risk weighted costs and benefits to the utility and customers and the broader community. Utilities need to be regulated on this basis, to provide the water services that customers need, at the lowest cost and with the lowest social and environmental impact.
These issues will be the subject of a workshop at the forthcoming International Water Association World Water Congress and Exhibition (WWCE) in Copenhagen. The workshop “Water efficiency: the fastest, cheapest, largest source of new water”, is hosted by the IWA Specialist Group on Efficient Urban Water Management and will take place at the WWCE 1.30pm to 3pm, on Wed 14 Sep. All interested delegates welcome. Contact: Stuart White on Stuart.White@uts.edu.au for further details.