The City of Sydney council is finalising plans for a recycled water network to be established throughout much of the city. It will include use of the Botany aquifer which extends from Redfern and Surry Hills, through Centennial Park and on to Botany Bay.
The rethink of the city’s water supply comes as the council finalises plans to decouple the electricity network from the statewide supply grid, instead using a new network of power generators throughout the CBD which will provide cheaper and more reliable power to the city.
”If you’re digging up the streets to put in the new trigeneration [electricity, heating and cooling] system, that’s the golden opportunity to put in a recycled water network,” the council’s chief development officer for energy and climate change, Mr Allan Jones, said.
”Sixty per cent of the cost of the infrastructure is in the trenching and traffic management. That’s why we’re also looking at automated waste collection.”
The council recently outlined plans for an automated waste collection system, which remains under study
”Piping water into the city and only drinking 2 per cent of that is just crackers,” Mr Jones said. Taking into account cooking, and any possible way of ingesting water, no more than 20 per cent of the city’s water needed to be of drinking quality, he said.
Central to the plan will use of recycled water and stormwater at new developments such as Barangaroo and Green Square.
Barangaroo will generate a surplus of recycled water which is expected to be used in water cooling towers and similar structures in other parts of the CBD.
This, coupled with use of the Botany aquifer, gives the city considerable flexibility. ”We’ve found we’ve got far more water resources than we’ve got consumption - the opposite to the way [Sydney Water] is going about it,” Mr Jones said.
”A third of the [city of Sydney] has got groundwater, which helps us address other issues like flooding and climate change adaptation. We can use the aquifer as storage.”
The aquifer gives council the ability to store and later withdraw large volumes of stormwater, at negligible cost. The volume of water in the aquifer is so extensive that since paper manufacturer APM stopped taking water from the aquifer in 2009 the water table has risen enough to cause flooding around Kensington and Kingsford, Professor Ian Acworth of the University of NSW said. APM had been taking 6 megalitres of water a day which it is now sourcing from Orica.
”The aquifer is a huge volume of water, and it is highly transmissive,” he said.
