Sydney’s future water supply

Sydney’s future water supply

The heat is on to secure Sydney’s future water supply

The City is moving to 'drought-proof' central Sydney’s future water supply with a bold program of local recycled water production and water efficiency measures.

The program also details how the City will diversify its sources of water by replacing 30% of its drinking water by 2030 with locally produced recycled water.

And the initiative is very timely. Sydney recorded its hottest ever day of 46.4°C on 18 January, while across Australia January 2013 was the hottest month on record, with an average temperature of 40.3°C.

The best levels of international and national scientific research are predicting such heat waves will become more frequent as a result of temperature rises caused by global warming.

For the City of Sydney, when the impacts of climate pressures are coupled with population growth and greater demand for council services, water demand is projected to rise by 30% to 44 billion litres over the next 17 years.

To deal with these challenges, the City has developed a comprehensive water strategy – known as the Decentralised Water Master Plan – aimed at reducing water demand by 10% by 2030.

This reduction in water use will largely be achieved through water efficiency programs targeting Council-owned locations and office buildings, apartments, houses, hotels and restaurants across the city.

Diversifying sources of water

At present, the City of Sydney area gets the bulk of its annual 33.7 billion litres of drinking water from Warragamba Dam, 70 kms west of the city, and from the desalination plant in Kurnell, 40 kms south of the city.

During the last drought, water levels at Warragamba Dam fell to all-time low levels, including to just 32.5% in February 2007. Water transfers from the Shoalhaven River prevented levels sinking to just 13%.

Importantly, only half of the City’s 'drinking-standard water' supply is used for drinking, bathing and cooking. The remainder is used for non-drinking purposes – flushing toilets, irrigating parks and running large-scale air-conditioning – all of which could be serviced by recycled water.

The sources of recycled water include stormwater, ground water, laundry water and waste water.

The City’s Decentralised Water Master Plan concentrates on a range of other initiatives to source local water supplies, including:

  • building major stormwater recycling projects at Sydney Park and Green Square to save up to 1 billion litres of water per year and reduce pollution of the Cooks River
  • building rain gardens within streetscapes to filter stormwater and reduce pollution discharged into waterways
  • investigating feasibility of major stormwater recycling projects within wetlands at Wentworth Park, Moore Park, Bicentennial Park in Glebe and Victoria Park at Broadway
  • investigating feasibility of waste water recycling projects at major development precincts such Green Square, Barangaroo and Darling Harbour.

Reducing pollution of waterways

Each year some 3,500 tonnes of sediment, nutrients and pollutants flow into Sydney Harbour and Botany Bay as a result of 26 billion litres of stormwater running-off streets and gutters.

The City’s Master Plan aims to halve this pollution by 2030 via projects to broaden the capture and cleansing of stormwater, while at the same time expanding the pool of recycled water.

Currently the City is actively reducing pollution through waste management, street cleaning, trapped gully pits and natural treatments such as rain gardens and wetlands to reduce the impacts on waterways and the health of marine habitats.

And later in the year, work will start on the City’s largest recycled water project at Sydney Park, where up to 850 million litres of stormwater – the equivalent of 340 Olympic pools – will be recycled.

A second major project is planned for the Green Square urban development precinct, which will produce over 300 million litres of water per year.

Both these projects are being undertaken in partnership with the federal Government, with the recycled water supplying City-owned properties as well as surrounding homes and businesses.

Local water projects

The City has already increased local water use by installing rainwater tanks at nearly 20 child care, kindergartens and community centres, including the Alexandria Child Care Centre, the Jane Evans Day Care Centre in Newtown and the Ultimo Community Centre.

There are also 20 stormwater harvesting and reuse projects completed or in planning to irrigate the City’s parks and sporting fields.

Completed projects include: Sydney Park at St Peters, Surry Hills Library, Pirrama Park in Pyrmont, Lillian Fowler Reserve in Newtown, Alexandria Oval and Prince Alfred Park in Surry Hills.

The completed and planned projects together are currently producing a total of up to 5 million litres of recycled water each year.

A number of parks, such as Victoria Park in Zetland, are using local bore water, which overall provides 27 million litres of water per year or 15 per cent of total water use of City parks.

The upshot of this commitment to diversifying the City’s water supply is increased resilience in the face of the challenges of climate change and a growing population, as well as cementing a more sustainable environment.

Last updated: Tuesday, 7 October 2014