Sustainable water for a changing climate


“It is now certain that global climate change is happening. What is less certain is how climate change impacts at a local level...The role and responsibility of all levels of government is to ensure we are fully informed, ready to act and work with our communities to address the risks, threats and opportunities.”
Lorraine Rosenberg
Mayor, Onkaparinga City

The challenge

Already South Australia’s most populous council with 156,000 residents, the City of Onkaparinga on the southern fringe of Adelaide is projecting its population will grow by 40,000 over the next 20 years.

To cope with such rapid growth sustainably in a region where water scarcity is always an issue, the Council is working to a much longer planning timeframe than typical for its plans and strategies.

In 2008, the City became the first South Australian Council to prepare a comprehensive Climate Change Strategy. Part of the strategy included a water management strategy, Water Futures, which supports a range of projects addressing water quality, supply and demand issues now and into the future to ensure the sustainable growth of the region.

A planned response to the rapidly changing and complex issue, the Water Futures strategy aims to create a sustainable water supply for the southern suburbs of Adelaide.  The Council has a lead role in the Water Proofing the South initiative that seeks to maximise wastewater and stormwater reuse through a number of major projects.

The project was part of federal funding for South Australian stormwater harvesting projects.

To this end, in 2011 the City of Onkaparinga Council contracted The Fyfe Group, South Australia to undertake a hydrological investigation for several smaller sub catchment areas of 290-300 hectares which drains to the sea at the Gulf of St Vincent.

The Council needed to improve the quality of stormwater runoff to the sea and to protect the area from flooding by expanding the stormwater drainage capacity.

Aldinga catchment, City of Onkaparinga

Modelling tool

To complete that analysis Fyfe used eWater’s urban stormwater modelling software, music (model for urban software improvements conceptualisation).

music is one of the few software tools available that can accurately simulate real-time water sensitive design. It is designed to help urban stormwater professionals visualise possible strategies to tackle urban stormwater hydrology and pollution impacts. Since first developed in 2001, the software has been used by thousands of professionals working in private practice and in state, regional and local government agencies throughout Australia.

Application

Fyfe Stormwater Engineer Bicky Shakya says “Fyfe did an analysis of the existing stormwater drainage system for several small catchments which drain into Gulf of St Vincent. The existing drainage system was checked and analysed using a combination of a detailed survey of the site and the drainage drawing plans provided by Council”.
 
“The program Drains and music were utilised to determine the drainage system capacity and the effectiveness of the existing water quality treatment train.”

With the help of music, the annual volume of water which can be harvested was determined and a water balance was defined.

“music has been utilised to determine the effectiveness of the existing treatment trains within each of the sub-catchments. It has been found that the quality of runoff being discharged into the gulf was of poor quality and did not meet the expected runoff quality standard. The annual runoff volume of water generated by each individual catchment was determined by music and indicated in the report for Council consideration.”

“music is a good tool which can help engineers involved in stormwater runoff quality monitoring,” Shakya says.

Shakya is using music v5, the latest version of the product, and says he finds the new version very user-friendly. He is also making good use of its enhanced bioretention functionality, he says.