Service delivery 4 Water Page 6 Alternative water sources and integrated water cycle management Page 14 Sewerage Page 22 Waterways Page 28 5 Service delivery Water 6 “Our water storages continued to rise during the first half of 2012–13, exceeding 80% full for the first time since June 1997.” Our aim Key achievements Disappointments • Met all water quality targets for • Failed to meet our target of less than Provide services that are valued E. coli, turbidity, aluminium and 1% for measurable transfer losses by our customers. disinfection by-products of total water delivered, partly due to water quality issues at the Tarago We will do this by: • Worked closely with water retailers to develop an annual Water Outlook, Treatment Plant and leakage from • Providing high-quality, safe and reliable which gives the community better the Tyabb Service Reservoir drinking water and fit-for-purpose access to water use and supply • Two water main bursts caused water from alternative sources information minor damage and disruption in • Providing safe sewage transfer, • Achieved a $12 million capital saving Glen Waverley and Viewbank. treatment and disposal on a new water pipeline servicing • Protecting and enhancing the health Melbourne’s growing area of Wyndham Challenges and amenity of waterways and bays • Worked with fire fighting agencies • Working with water retailers, local • Managing flood risk to successfully protect water councils and the development industry catchments from bushfires. to maximise use of stormwater and • Adapting our assets to address recycled water while balancing use climate change and variability from traditional catchments and dams • Planning, operating and maintaining • Continuing to research and assess our built and natural assets efficiently the impact of seasonal and long- by incorporating innovative and term climate change on hydrology whole-of-life system approaches projections. • Providing for continuity of service by improving the way we plan for, respond to, and recover from extreme events. 7 Service delivery Water Our water supply system Managing demand and supply Reflecting below average rainfall, 2012–13 stream flow of 478 billion Melbourne Water’s supply system Our water storages continued to litres into the major harvesting comprises: rise during the first half of 2012–13, reservoirs was 3.1% below the long-term exceeding 80% full for the first time • 157,000 hectares of protected average. The year started well with since June 1997. However, even though catchments in the Yarra Ranges above average stream flow for the first total reservoir storage was 70.1% three months, although the last nine • 10 reservoirs with a total capacity or 1,271 billion litres at 1 July 2012, months of 2012–13 were below average. of 1,812 billion litres it had only increased to 70.8% or • 34 water treatment plants 1,282.9 billion litres by 30 June 2013. The total system storage volume of 70.8% at 30 June 2013 is the highest Rainfall across Melbourne’s catchments • 1,057 kilometres of water mains for this time of year in 16 years. for 2012–13 was below the long-term • 214 kilometres of aqueducts It represents a significant recovery average following two wetter years from June 2009 when storage levels • 64 service reservoirs. with back-to-back La Niña events in fell to their minimum of 25.6% during 2010–11 and 2011–12. Rainfall over the 1997 to 2009 Millennium Drought. the major catchments in 2012–13 was between 8.6% and 14.7% below average, with the catchment weighted average being 3.1% below. Thomson catchment highlighted the variability in monthly rainfall, receiving only 8 millimetres in January, yet 220 millimetres in June. Figure 1 Goulburn River Melbourne Water Yea N water supply system Toorourrong Reservoir Yea-Sugarloaf Pipeline Yan Yean Upper Yarra Reservoir O'shannassy Reservoir Reservoir Water supply pipeline, aqueduct Western Water Greenvale Sugarloaf Reservoir Reservoir Maroondah (Sunbury) Reservoir Water supply storage reservoir Yarra Valley Water Water supply catchment area Western City West Thomson Water Water Reservoir Retail Water area boundary (Melton) Silvan Reservoir Tarago Reservoir Southern Rural Water Melbourne (Macalister Irrigation District) Cardinia Reservoir Gippsland Water (Neerim South) Gippsland Water (Warragul) Port Phillip Bay South East Water WesternWestern Port Port French Island Phillip Bass Strait Island 8 F ig Monthly uaverage rainfall at Melbourne’sr major harvesting reservoirse 2 Rainfall 2012-13 (mm/month) Rainfall 30-year long-term average (mm/month) F ig Monthly uaverage streamflow at Melbourne’sr major harvesting reservoirse 3 Steamflow 2012–13 (ML/month) Steamflow 30-year long-term average (ML/month) 200 150 F 100 ig Melbourne’su water storage r e 4 50 Storage volume (%) 0 120000 100000 Jul-2012 80000 60000 Aug-2012 F ig 40000 Annual streamu flow at Melbourne’s major harvesting reservoirs (Upper Yarra, Thomson, r 20000 Sep-2012 Maroondah, O’Shannassye 5 Reservoirs) Oct-2012 0 Financial year reservoir inflow (GL) 2006–07 infows – lowest on record (180.0 GL) 100% Nov-2012 Long-term average (613.0 GL/a) Jul–2012 1997/98–2011/12 average (420.5 GL pa) 80% Dec-2012 60% Aug–2012 Jan-2013 40% Sep–2012 20% Feb-2013 0% Oct–2012 Mar-2013 Nov–2012 1200 Jan–1997 Apr-2013 960 Jan–1998 Dec–2012 May-2013 720 Jan–1999 Jan–2013 480 Jan–2000 Jun-2013 240 Feb–2013 Jan–2001 0 Jan–2002 Mar–2013 1903/04 Jan–2003 Apr–2013 Jan–2004 1912/13 Jan–2005 May–2013 1921/22 Jan–2006 Jun–2013 Jan–2007 1930/31 Jan–2008 1949/50 Jan–2009 Jan–2010 1958/59 Jan–2011 1967/68 Jan–2012 Jan–2013 1976/77 1985/86 1994/95 2003/04 2012/13 9 Service delivery Water Desalination plant on standby New pipeline to service growth • Ensuring all connections of in Wyndham alternative supply mains were The Victorian Desalination Plant open and operational was commissioned in 2012. Construction of a water pipeline to service Wyndham, one of the fastest • Daily surveillance along pipelines The AquaSure consortium undertook growing municipal areas in Australia, supplying the CBD to ensure no performance testing from September will cost $12 million less than originally impact from third party works to December 2012, with desalinated forecast due to savings identified as such as unknown excavation water meeting all required drinking water part of a joint integrated water cycle standards. The final commissioning test • Cancelling programmed works management approach with City involved running the plant at maximum associated with supply to the CBD West Water. capacity for 30 consecutive days. • Melbourne Water’s Water Control Water demand from the City West During commissioning, a total of Centre undertaking daily checks Water zones of Cowies Hill and West 24.9 gigalitres of desalinated water of the controlling pressures at key Werribee is forecast to increase was transferred to Cardinia Reservoir. locations to ensure adequate supply significantly over the next 25 years, However, as the Victorian Government • Reconfiguring water supply zones requiring construction of a new main placed a zero gigalitre order for 2012–13, to meet increasing summer demands. to service growth. the plant ceased production on completion of testing. A further zero Stage 2 of the St Albans to Werribee Water main bursts gigalitre order was placed for 2013–14. Pipeline project will now cost $12 million On 29 October 2012, a water main less following an analysis of the benefits In the lead up to the first supply of burst in Knights Drive, Glen Waverley, of integrated water cycle management desalinated water, Melbourne Water due to a faulty valve. The damaged and the impacts of changing growth worked closely with AquaSure, the section was shut down within an rates and peak demands. Department of Environment and hour and isolated to ensure no impact Primary Industries1 and impacted The diameter of the new pipeline will to water supply in the local area. water retailers to develop protocols be reduced by installing a ‘third-pipe’ Melbourne Water worked to assist for coordinated operation of systems carrying recycled water to households the owners of the one property that and infrastructure. This included for non-drinking purposes, resulting was damaged. innovative hydrodynamic modelling in significant reductions in peak potable It is estimated that about two million of Cardinia Reservoir to predict the water demand. mix of the desalinated water in the litres of water, equating to 0.2% of reservoir and the potential impacts Melbourne’s daily water use, flowed Working collaboratively into the stormwater system. on water quality. to maintain supply On 20 December 2012, a water main While the desalination system will Following ground movement in burst in Martins Lane, Viewbank. operate on an as-needs basis, further October 2012 from the construction To avoid leaving Melbourne’s CBD and work will be undertaken with the of a new hospital, City West Water northern and western suburbs without operator to refine and integrate had to isolate its Elizabeth Street water, crews first redirected water from operating arrangements. transfer mains, which provide water other parts of the system before the to Melbourne’s CBD. damaged section could be shut down. To ensure a continued water supply The burst main, caused by a faulty to the CBD, Melbourne Water worked valve on the Silvan-Preston main, with City West Water on contingency resulted in some land erosion damage measures including: to several properties and Melbourne Water worked with emergency services to assist residents. 1 Formerly two separate departments known as the Department of Sustainability and Environment and the Department of Primary Industries. 10 Melbourne Water Annual Report 2012–13 Water consumption and quality 1 December 2012. Melbourne recorded Retail water consumption nine consecutive days of above 32°C in Stage 1 water restrictions were lifted Melbourne Water supplied 404,260 March 2013.