<p>Leakage and Pressure Management Strategy for the Gold Coast developed by Wide Bay Water (WBW) from Gold Coast Water slides</p><p>Introduction • In 2002/03 approximately 10% of potable water supplied was unaccounted for water (UFW) • Typically, 50% of UFW is water lost through undetectable leaks • Wide Bay Water (WBW) developed a leakage and pressure management strategy for the Gold Coast</p><p>District Metered Areas • Water supply network to be divided into District Metered Areas (DMAs) • Each DMA includes approx. 500-1500 connections • Each DMA preferably fed from one water main • Flow meter and flow-modulated pressure reducing valve (PRV) installed on feed main</p><p>Reducing Leakage in a DMA • Flow meter allows the quantity of water entering DMA to be monitored • During the early hours of the morning, the majority of measured flow is leakage • Leaks are located using specialised equipment then repaired • DMAs allow new leaks to be identified quickly and make locating leaks easier</p><p>Reducing Pressure in a DMA • PRV allows the water pressures in the DMA to be controlled • Using a flow-modulated PRV allows the water pressure to vary according to the demand • This ensures adequate water pressure during high demand periods and for fire fighting, while reducing excessive night time pressures</p><p>Advantages • Reduced consumption due to repair of leaks • Reduced consumption due to lower pressure • Reduced water main and property service breaks • Improved customer service • Longer asset life • Reduced maintenance and renewals costs for water mains and property services</p><p>Negative Impacts • Potential problems with internal plumbing, hot water services or irrigation systems due to reduced water pressure • Potential water quality problems associated with more ‘dead ends’ in the water network</p><p>Environmental and Social Impacts • Benefits associated with deferring or reducing the need for additional capacity in the water supply system • Low cost option • Negligible energy consumption and Greenhouse Gas generation</p><p>Burleigh Waters Pilot Trial • DMA created which incorporates 3,310 connections • Single water main supplies the area at the corner of Deodar Drive and Symonds Road • Flow meter and flow-modulated PRV installed at the same location</p><p>• Reduction in background leakage of 2.95L/second (0.25ML/day) – 48% reduction to the minimum night flow in the area • Pilot trial results significantly better than expected at the start of the trial • Additional water savings due to consumption reduction are expected but have not been quantified</p><p>Citywide Implementation • 2 additional pilot trials are to be undertaken in Beenleigh and Eagleby • Planning phase for Citywide implementation approved by Council • 108 permanent DMAs planned for the existing areas of the City (highrise strip to be excluded) • Future development areas to have water supply networks designed as DMAs</p><p>Citywide Water Savings • Conservative estimate of savings for leakage and pressure management adopted in current water balance – 20ML/day • Based on a reasonable estimate of leakage per DMA, extrapolated across existing and future areas of the City • Implementation will occur over a period of time. • More conservative timeframe adopted than is included in current construction plan • Capital cost to implement in existing areas is $6.5million • Ongoing costs associated with maintenance, and leakage detection and repair • Reduced revenue will be offset by reduced water treatment and asset renewals costs, and deferral of headworks Conclusions • Leakage and pressure management presents the opportunity for significant water savings at low cost • Suggested that the Advisory Committee adopt a conservative estimate in the order of 20ML/day to be saved by 2056, and that this figure be revised as further information becomes available</p>