Perth is now saving more than 100 billion litres of water through recycling and efficiency initiatives and Western Australia is recycling around 21 billion litres of water, which is up 75 per cent over the last decade.
The encouraging results were highlighted in the Water Corporation report Water Forever Whatever the Weather – Water Recycling and Water Efficiency.
Water Minister Terry Redman said the report confirms the importance of recycling and water efficiency to improve Perth’s resistance to the drying climate.
“Western Australia is now recycling around 21 billion litres of water each year for a number of uses including irrigating public open space, on-site reuse at our waste water treatment plants, and industrial/commercial use including tree farms across the State,” he said.
The Water Corporation has set a number of goals to achieve by 2030. They include working with households, businesses and communities to reduce water consumption by 15 per cent; aiming to increase the use of recycled water for parks, gardens and in industry in Perth to 30 per cent, well up from the current level of 13.5 per cent; and developing up to 100 gigalitres of new water sources with desalination being regarded as an important new source, as well as groundwater replenishment and secure groundwater sources.
“This report tells us two things; that water efficiency measures and recycling have been very effective in securing supply and reducing our footprint, and that there is more work to do,” said Redman. “Water recycling remains a major focus for the future, with groundwater replenishment potentially saving up to 28 billion litres by 2030, and new opportunities being explored all the time.”
There are a number of ways the state government is improving water recycling levels.
Initiatives include groundwater replenishment, which involves recharging high quality recycled water to groundwater and storage for future use; dual reticulation recycling schemes for new subdivisions, where two separate pipes deliver two types of water – one for drinking water, another for non-drinking uses such as garden watering or toilet flushing; and sewer mining, which is the process of extracting, treating and using waste water before it reaches a waste water treatment plant. Although sewer mining is not practiced widely in Perth as groundwater is often a cheaper alternative, it may become a more attractive option with groundwater sources becoming fully allocated and several proposals currently under investigation.
The Minister said that since 2000-01, Perth residents have reduced their annual drinking water use from 191,000 litres to 135,000 in the last financial year.
“West Australians have been very responsive to water efficiency measures and we are well on the way to meeting our 15 per cent per capita water use reduction target by 2030. Even so, Perth remains one of the highest per capita water-using cities in Australia, so we need to stay firmly on task,” he said.
Redman said the two-day-a-week sprinkler roster in Perth accounted for slightly more than half of the 100 billion litre saving.
Other factors including increased urban density and changing patterns in home occupancy are contributing a further 26 billion of litres in savings a year compared to per capita usage levels in 2001.