Along with the community’s input, the review involved complex modelling and analysis to identify a portfolio, or mix of measures, that delivers water security into the future. The water planners took account of a range of factors, including achievements to date, advances in technology, updated population projections, rainfall and dam inflow scenarios, results of climate change research, cost effectiveness analysis, and social and environmental impacts.
The portfolio approach involves analysing different combinations of existing and new water supply and demand measures to identify the mix that provides water security for people and for the environment at the least cost. This challenge includes preparing for extreme drought. Our modelling made sure our water supply system could withstand a drought more than twice as severe as the recent prolonged drought in greater Sydney.
A process summary document has been developed to provide more detail on the portfolio approach to water planning and explain how the security of supply has been established. The document can be found at www.waterforlife.nsw.gov.au/review.
Thekey measuresin the 2010 Metropolitan Water Plan portfolio include:
Water efficiency
The water conservation and water efficiency measures in the Metropolitan Water Plan aim to save 145 Mm3/yr by 2015 (Figure 1.2).
Sydney Water is implementing a range of innovative programs to use water more efficiently in homes, businesses and public facilities, including:
Almost one million residential water efficiency rebates and offers since the water efficiency program began including WaterFix visits to more than 470,000 homes saving 10 Mm3/yr and distribution of 201,000 free Do-it-yourself Water Saving Kits saving about 0.8 Mm3/yr.
Water Wise Rules which have saved an estimated 19 Mm3of drinking water since they were introduced in June 2009.
New homes are being designed to use 40% less water from Sydney’s mains water supply.
More than 400 business organisations taking part in Sydney Water’s Every Drop Counts Business Program, saving about 17 Mm3/yr of water a year.
Sydney Water’s leak reduction programs are estimated to be saving around 30 Mm3/yr through investing almost $100 million and inspecting more than 20,000 km of pipes.
Thanks to the water-saving efforts of homes and businesses in the greater Sydney region, Sydney is using the same amount of water now as in the early 1970s–even though serving an extra 1.4 million people.
MilestonesinWaterReuse:TheBestSuccessStories
Water recycling
Sydney’s rainfall is highly variable and future droughts are likely to be more severe due to climate change of climate change and a growing population, it makes sense to balance supply from the dams with sources of water that do not rely on rain.
The Metropolitan Water Plan aims to reduce demand for drinking water by around 70 Mm3/yr by 2015 through water recycling of treated wastewater, greywater and stormwater for non-drinking purposes in homes, industries and agriculture (Figure 1.3).
Projects completed or underway include:
The Replacement Flows Project at St Marys that will provide 18 Mm3/yr of highly treated recycled water to the Hawkesbury-Nepean River as environmental flows (Figure 1.4). This will save dam water normally released to maintain the river environment downstream.
The Wollongong Recycled Water Plant that supplies around 7 Mm3/yr.
Australia’s largest dual-pipe residential recycling scheme at Rouse Hill that supplies about 2.2 Mm3/yr to 19,000 homes for toilet flushing and watering gardens. This project has the capacity to be expanded to supply up to 36,000 homes as the area grows.
Sydney Water is now building similar residential schemes at Ropes Crossing and Hoxton Park in south-western Sydney.
The Rosehill-Camellia Recycling Scheme now supplies 4.7 Mm3/yr of recycled water to major industrial and commercial users. It came online in 2011. It is the first project delivered using the third party access regime under the NSW Water Industry Competition Act 2006.
Around 70 local scale stormwater reuse projects in the greater Sydney area will save over 2 Mm3/yr of water a year.
In 2010, use of recycled water was saving about 33 Mm3/yr of water a year that might otherwise come from Sydney’s drinking water supplies. In addition, the Water Industry Competition Act 2006 is making it easier for the private sector to invest in recycling.
0 20 40 60 80 100 120 140 160
06/07 07/08 08/09 09/10 10/11 11/12 12/13 13/14 14/15 Water savings (Mm3/yr)
Year
Sydney water efficiency programs
Water wise Regulatory Leak reduction Business Residential
Figure 1.2 Projected water savings in Sydney.
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Desalination
In 2007 when the Sydney storages fell to 35% of full storage, the NSW Government initiated the construction of a desalination plant with 90 Mm3/yr capacity to supply up to 15% of Sydney’s current water needs.
The desalination plant came on line in January 2010 (Figure 1.5). It has run at full capacity during a two year“defects correction period”which ended in June 2012. During this period, the operation of the plant was monitored for water quality, performance and impacts on the supply system. After this period, the following operating rule will apply: the plant will operate at full production capacity and supply desalinated water to Sydney Water’s area of operations when the total dam storage level falls below 70% and will continue to do so until the total dam storage level recovers to 80%.
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06/07 07/08 08/09 09/10 10/11 11/12 12/13 13/14 14/15 Recycled water (Mm3/yr)
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Recycled water use in Sydney
Enviromental flows Residential Industrial/commercial
Irrigation STP reuse
Figure 1.3 Projected use of recycled water in Sydney.
Figure 1.4 St Marys water recycling plant supplies 18 Mm3/yr for environmental flows (Photograph courtesy of Sydney Water).
MilestonesinWaterReuse:TheBestSuccessStories
The desalination plant uses reverse osmosis technology to extract fresh water from seawater. Water from the desalination plant enters the system at Erskineville and is distributed to approximately 1.5 million people across the Sydney CBD, inner west, eastern suburbs, southern Sydney and parts of the Sutherland shire, and at times as far west as Auburn.
The energy requirements of the plant are 100% offset byrenewable energyfrom a 67 turbine wind farm near Bungendore.
The construction of the desalination plant has made the Sydney supply considerably more secure in prolonged drought sequences.
System upgrading
Long-term plans are to augment the Shoalhaven water supply transfer system. The timing of this initiative will depend on factors such as future climate predictions, population growth and demand. These factors will be reviewed between now and 2014 with a view to having an augmented system operational around 2025.
Drought contingencies
A number of measures are available to be implemented in extreme drought to slow the depletion of dams. These include:
increasing the amount of water transferred from the Shoalhaven by making more of the stored water at Tallowa Dam available, accessing groundwater, implementing voluntary water usage targets, up scaling the desalination plant, and investigating the optimal rules for reducing environmental flow releases from dams. Pricing is also being examined as a potential tool for managing demand during a drought.
Drought restrictions
New simpler restrictions, based on the Water Wise Rules, will be implemented should Sydney experience another drought.
The supply-demand balance
Drinking water use in Sydney peaked at 635 Mm3/yr in 2002–2003.
Water use has now been reduced to about 500 Mm3/yr through the effect of water saving measures and the development of water recycling.
The capacity of the supply system is currently assessed at around 620 Mm3/yr after accounting for the severity of the 2002– 2007 drought, adding the capacity of the Sydney desalination plan and deducting the increased environmental flow now being released downstream from the storages.
Figure 1.5 The Sydney desalination plant at Kurnell (Photograph courtesy of Sydney Water).
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1.4 THE 2014 METROPOLITAN WATER PLAN
Work has now commenced on the preparation of the 2014 Metropolitan Water Plan. The work includes: