In 2013, total water consumption for the greater Perth region was approximately 470 GL. This comprised about 225 GL of private water supply, 240 GL of public water supply through Water Corporation of Western Australia, and a further 5 GL of recycled water supplied to industry in Kwinana from the Water Corporation's Kwinana Water Recycling Plant. Average domestic water use decreased from 191 kL per person per year in 2001 to 131 kL per person per year in 2013-14.423 Despite this, Perth remains one of the highest water using cities in Australia. The main source of water supply for Perth is groundwater, with less than a quarter of the total water source coming from surface water. Current supply is sufficient to meet demand under average climatic conditions, and recent construction of desalination plants has increased the resilience of supply in relation to drought. However, further augmentation will be required beyond 2020 to address population growth and address climatic variability. In the Kwinana Industrial Area and the Rockingham Industrial Zone, readily accessible water supplies are not sufficient to meet projected long-term demand for industry. An assessment of alternative water supply options including managed aquifer recharge of treated wastewater will be completed in 2015.
Key drivers of demand are the region's population (which is projected to grow at a rate of 2.5 per cent per year), and changes in climate over several decades. The Water Corporation is operating under medium- and long-term water security plans for Perth, including Water Forever - Our 10 year Plan for Perth, Water Forever - Our 50 year Plan and Water Forever - Water Recycling and Efficiency. The goals for 2030 under these plans are to:
■ reduce water use by 15 per cent - by working with households, businesses and communities;
■ increase water recycling to 30 per cent - by increasing the use of recycled water in parks, gardens and industry; and
■ develop up to 100 GL of new water sources - desalination, groundwater replenishment and secure groundwater sources are all important sources to secure Perth's future water supply.
In particular, Water Forever - Our 10 year Plan for Perth aims to sustainably drought-proof Perth by 2022, by:
■ expanding the Southern Seawater Desalination Plant;
■ transferring groundwater abstraction to the deeper aquifers to protect the groundwater environment and secure groundwater supplies;
■ replenishing deep aquifers with recycled water through a new groundwater replenishment scheme, subject to receiving necessary approvals;
■ continuing to make gains in water use efficiency while preserving an outdoor lifestyle and enabling continued growth; and
■ using wastewater recycling as a resource for industry, public open spaces and agriculture.
A $4.37 billion investment plan over 10 years has been developed to implement these initiatives.
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423. Water Corporation (2014)