With Perth located in one of the driest regions of the driest continent on earth, water recycling has proven to be one of the most viable solutions to securing water supply into the future.
Set to present at the WAter – A State of Extremes Conference, Water Corporation Strategic Projects Senior Principal Nick Turner said while the utility’s groundwater replenishment program has been hugely successful, there is definitely room to expand.
“Looking forward, the drying trend is going to continue in Perth. While in WA, we didn’t have the ‘millennium drought’ experienced on the east coast in the 2000s, rainfall has been steadily declining since the 1970s,” Turner said.
“We continue to investigate ways to increase water recycling in Perth, in line with our target in Water Forever to increase water recycling to 60% of all wastewater in Perth by 2060. This includes groundwater replenishment potentially supplying up to 20% of Perth’s drinking water needs by 2060.”
Water Forever is Water Corporation’s plan to secure water supplies in a drying climate, which includes a three-pronged approach to developing new water sources, reducing water use and increasing water recycling, Turner said.
While Perth is the first city in Australia to have a groundwater replenishment scheme – with the first stage of the scheme recharging up to 14 GL of recycled water to aquifers each year – Turner said Water Corporation will continue to investigate sustainable solutions to water demand.
“An emerging area of interest in recycled water is for the irrigation of public open space, which are either irrigated by groundwater where allocation may need to be reduced or new areas where no allocation is available,” he said.
“In many cases these may need a decentralised approach where wastewater is taken directly from the wastewater system, treated locally, then used for irrigation.”
Turner added that expanding water recycling in Perth is not without its challenges, particularly when applied for irrigation.
“One of the roadblocks to water recycling is matching seasonal demand for irrigation water, to the supply of treated wastewater,” he said.
“The treatment plant is biological, so can’t easily be turned on and off – and there is no demand in winter for recycled water. The only practical way of storing in winter is to recharge to aquifers, which requires a suitable aquifer and the relevant approvals.”
While large-scale recycling schemes are by no means a quick or easy solution to ongoing water security concerns, Turner said engaging the community is the first step in moving forward with recycled water projects.
“A purpose-built visitors centre was constructed at the site of the Groundwater Replenishment Trial. Engagement with the community is crucial.
“Water Corporation carried out its most extensive community engagement program throughout the Groundwater Replenishment Trial. The aim was to bring the community on board with the journey and educate people about why groundwater replenishment is so important.”