Water Journal : Water Journal November 2012-1
refereed paper demand management water NOVEMBER 2012 87 Abstract With the increasing population in urban areas driving higher demands on an already limited resource, demand management is crucial to ensure the long-term security of water supply. Gosford City Council undertook a series of demand management strategies that resulted in a 36% reduction in total demand from 301L/capita/d to 193L/ capita/d over the period 2001 to 2008. This reduction appears to be mainly driven by the increasingly severe levels of water restrictions imposed on the householders; however, restrictions appear to have been partially offset by the uptake of rainwater tanks by the householders, and potable water savings were obtained in part by the uptake of water-saving (REFIT) devices such as low- flow shower roses. A household survey, undertaken as part of this study, provided insight into rainwater tank installation and water usage behaviours in the home and is discussed alongside the Council’s rebate and REFIT kit uptake records. Introduction With the demand for town water increasing as a result of growing population combined with limited economically viable fresh water resources, there is an added emphasis for each individual household to contribute towards reducing water consumption. This paper presents the water demand management strategies adopted by Gosford City Council (GCC) to efficiently manage one of the severest droughts experienced by its residents over the last 50 years. Figure 1 presents water consumption and population growth between 1993 and 2009 and illustrates that total demand increased with the population until 2002. However, since 2002 demand significantly reduced, despite the continued increase in population. Further, the decrease in water consumption appears to have started with the introduction of Level 1 Restriction. As can be seen, water use restriction levels were gradually raised from Level 1 to Level 4 (indicated with symbols R1, R2, R3 and R4 in Figure 1) between 2002 and 2006. Table 1 provides a brief description of the different levels of water restrictions. Gosford City Council (GCC) has applied water restrictions since February 2002 when Level 1 Restriction was introduced (Sydney Water, 2010). In October 2006, GCC enforced the highest restriction of Level 4, which resulted in a complete ban of town water for external water use. P Hagare, D Hagare, A Modessa, W Quennelle, B Koizumi-Smith A review of demand management strategies undertaken by Gosford City Council EFFECT OF REBATE SCHEME AND WATER RESTRICTIONS ON RAINWATER TANK UPTAKE RATE AND THEIR IMPACT ON WATER DEMAND Table 1. Various restriction levels and their effective periods (GCWSC, 2009). Level Restriction Period Description 1 February 2002–May 2004 Water restricted from washing down of paved surfaces, except where required by law and for health and safety. 2 May 2004–June 2006 Watering of lawns and gardens restricted to use of hand-held hoses on alternative days for up to one hour over fixed time slots in a day. All cars and boats to be washed with a bucket. 3 June 2006–October 2006; June 2009–November 2011 No fixed hoses, sprinklers or handheld hoses permitted for use for watering lawns and gardens. Only watering cans are permitted for use at any time of the day. 4 October 2006–June 2009 Complete ban on the use of town water for external uses. 20,000.0 180,000 140000 16,000.0 18,000.0 20,000.0 140,000 160,000 180,000 10,000.0 12,000.0 14,000.0 80,000 100,000 120,000 Supply,ML/yropulation Population / 4,000.0 6,000.0 8,000.0 40,000 60,000 80,000 WaterSPo Water supply, ML/yr R1 R2 R3R4 R3 - 2,000.0 - 20,000 1992 1997 2002 2007 Year R1 R2 R3R4 R3 Year Figure 1. Variation of water demand and population between 1993 and 2009.
Water Journal December 2012
Water Journal September 2012-1