Water Journal : Water Journal May 2011
demand management refereed paper 68 MAY 2011 water technical features Abstract Many jurisdictions have implemented major supply augmentation schemes to compensate for population growth and climatic variability. Demand management (water efficiency) strategies are also embedded into urban water management across many Australian utilities. However, the focus on demand management is now at risk of dilution in a less supply- constrained context. This paper explores the future of demand management in utilities with (perceptions of) reduced water scarcity. Using the Central Highlands Water (CHW) Ballarat & District and Maryborough Water Supply Systems (hereafter referred to as Ballarat and Maryborough) as case studies, this paper details current efforts to not only sustain existing efficient water use behaviour but explore additional strategies for managing demand after major supply augmentation and perceived 'breaking of the drought'. Following the case study findings, the role of demand management in the future is discussed, including how programs can be measured and justified, both in terms of water and energy saved and wider sustainability and community engagement benefits. Introduction Demand management: a changing context Demand management programs have been increasingly implemented in cities and towns across Australia. These have been driven by droughts and a focus on the need to conserve water as well as future supply-demand balance shortfalls resulting from rising population and uncertainty over future inflows to dams, including as a result of climate change. Demand management (water efficiency) programs, such as leakage repair and installing lower-flow showerheads are generally more cost-effective than looking to new supply infrastracture to meet any shortfall, and at the same time save energy through reduced system pumping -- and in the case of end uses such as showers and washing machines -- water heating. However, in addition to utlities implementing water demand management programs, many have built new supply infrastructure including desalination plants, pipelines and the development of new groundwater resources. This increase in available supplies, together with recent rains in several parts of Australia, has implications for community perceptions of water scarcity and potentially changed approaches to water conservation and demand management. From the utility perspective, there is a need to manage future revenue streams to ensure recent infrastructure investments can be paid for, while still promoting sustainable water use. The future role of demand management needs revisiting in this unchartered context. Aims of the Paper This paper uses Ballarat and Maryborough as case studies to explore current efforts to sustain existing efficient water-use behaviours following supply augmentation via connection of the Superpipe to Ballarat, and additional surface water and groundwater supplies to both Ballarat and Maryborough. Potential demand management options to complement the existing portfolio are explored and evaluated. Finally, the discussion focuses on the future of demand management in a post supply-constrained context in Australia and the need for a new framework in which to evaluate its benefits and costs. Ballarat Context The Ballarat and Maryborough regions are located approximately 115km north-west of Melbourne, Victoria. The state-owned water utility, Central Highlands Water Corporation, currently services around 120,000 people within the region (CHW 2010b) and manages the bulk supply of around 12,500ML/yr of water (including 60,470 connections) (CHW 2010a). Head works infrastructure managed by the utility includes 31 reservoirs, 13 diversion weirs and 30 groundwater bores (CHW 2010a). The region is set to experience significant population growth over the next 50 years. The population serviced by the Ballarat & District Water Supply System (c. 115,000), for example, is expected to almost double, as shown in Figure 1 (CHW 2010b, VIF 2008). Further strain on water supplies may stem from the decline in projections to rain-fed storages and the number of persons per dwelling, following a national trend of larger houses with fewer occupants and thus a greater number of potable connections (ABS 2006). Recent Events In the years leading up to 2008, prolonged drought and record low inflows saw Ballarat's water supplies fall to a historical low of 7.4%. The situation resulted in the drying of Ballarat's central recreation lake, Lake Wendouree. In 2006, following the release of the Victorian Government White Paper and Central Region Sustainable Water Strategy, the Institute for Sustainable Futures assisted CHW in creating a Demand Management (DM) Strategy which identified demand side options to be considered for D Giurco, T Boyle, S White, B Clarke, P Houlihan Exploring a new paradigm of future demand management options THE INFLUENCE OF DECLINING PERCEPTIONS OF SCARCITY Figure 1: Population growth projections for CHW Ballarat & District Water Supply System.
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