WATER is an increasingly precious commodity in Australia, and an innovative approach to water issues at a local reserve has seen the City of Kalamunda lauded for its innovation and sustainability.
Seven years ago, the City was confronted with a major problem.
Forrestfield’s Hartfield Park Reserve (HPR), a large multi-use reserve that accommodates a variety of sporting and recreation facilities, was earmarked to expand by five hectares, however the City of Kalamunda was unable to gain a licence to gain the 50 million litres of ground-water needed to sustain the expanded facilities
The City tasked project delivery coordinator Dan Nelson with finding an alternative to ground-water, and the concept he came up with – referred to as the Managed Aquifer Recharge project (MAR) is a WA first that manages to reduce hard surface runoff while simultaneously restoring water levels in Perth’s heavily depleted ground water system.
The project, developed by Mr Nelson over the last seven years, might sound confusing but at the base level, it is surprisingly simple.
During winter, the City takes water run-off from the Water Corporation’s Woodlupine Main Drain – water that is ultimately destined for the ocean – filters it, then re-injects the water into the Leederville aquifer, a massive aquifer that runs from Geraldton down to the South West, at the rate of six litres per second, increasing to 30 litres per second in the future.
Most of the State’s drinking water comes from the Leederville aquifer.
This then increases the City’s license to take water allocation under the Water and Irrigation Act of 1914 (RIWI).
Mr Nelson said the easiest way to think of the concept was swapping an existing water tank for one of the largest water tanks in the world in the form of the Leederville aquifer.
“Nature provides the storage for free, our cost is making sure we protect that,” he said.
“All the infrastructure we have at Hartfield Park Reserve is risk and mitigation infrastructure to make sure we don’t clog the aquifer.
“For every litre we put in, we get a litre added to our licence.
“The biggest constraint to harvesting storm water in WA is the ability to store the water, because we don’t get that rain in the summer, whereas in the east coast you get a top-up with periodic rains during summer.
“We’ve got a massive tank underneath us, so we use that.
“On a grand scale, rather than spending $100 million on a 200 million litre water tank, we’ve spent $500,000 on a filter system, we inject it in winter and then we pull it back through our irrigation systems in summer.
“If you use scheme water as a baseline, harvesting this water is significantly cheaper, about 30 cents compared to about $2.30 from scheme water.
For his efforts in designing and implementing the MAR system, the City of Kalamunda won the Innovation for Sustainability Awards at the Australian Water Association WA Water Awards, while Mr Nelson was a finalist in the Water Professional of the Year category.
However the system is so innovative that it is already being used as a model for other local government organisations.
“Probably four times a month we’re having a bus trip out here with other local government organisations, I’m having to combine them because there are so many.
“When we started, the City had to do everything, there’s no other site like this and the City of Kalamunda developed the infrastructure itself.”
City of Kalamunda Mayor John Giardini applauded the team behind the project, particularly Mr Nelson.
“We are extremely proud to receive the award, and I congratulate the CEO Rhonda Hardy, Director Dennis Blair and Project Manager Daniel Nelson and all who have assisted to date.”
“The project showcases the dynamic and ethical leadership that is required to enable innovation in the public sector.
“It was developed by a City officer, who with the support of the team convinced the executive and the council that is was worth the investment.”