The Grange Golf Club Wetland and ASR Scheme is a major urban stormwater management project for irrigation. The Club is located at the downstream end of the 4.2 km2 Trimmer Parade stormwater catchment in the suburb of Seaton in the City of Charles Sturt.
Download the proposal brochure (pdf 400 kb)
The scheme concept is to harvest approximately 320 Megalitres (ML) of urban stormwater by diverting water from the Trimmer Parade and adjacent West Lakes Boulevard systems into a wetland constructed on the golf course. Using wetland processes the water will be treated to a standard suitable for injection into the locally used and stressed aquifer. The water will then be extracted from the aquifer in summer for sustainable irrigation use.
The scheme is presented pictorially in the accompanying brochure. The scheme is identified as a priority in the City of Charles Sturt’s Trimmer Parade Catchment Initial Urban Stormwater Master Plan (USMP). The USMP identifies wetlands at the Grange Golf Club as providing the major opportunity for water quality improvement for stormwater discharges into West Lakes and the Port River. The USMP also indicates that the Grange Golf Club is the only location within the catchment capable of implementing a viable wetland and ASR scheme for major water reuse. The feasibility study indicates that the scheme will intercept and reuse approximately 12% of the total urban stormwater inflow to the West Lakes system.
The groundwater resource, the upper Port Willunga Formation of the Tertiary aquifer system underlying the Adelaide Plains is extensively used in the West Lakes area for irrigation of recreation areas during the summer months. This leads to a drop in local water levels of up to 18 metres over the irrigation season. Whilst groundwater levels recover in winter, observations over the last ten years have indicated water levels in the area are decreasing by around 0.25 metres per year. Similarly concerning are the observed salinity increases of 5 to 10 mg/L/yr due to induced leakage from adjacent saline aquifer intervals.
Current irrigation of the Grange Golf Club’s two 18-hole golf courses uses approximately 300 Megalitres of groundwater withdrawn from the upper Port Willunga Formation. The Grange Golf Club is the single largest groundwater user in the region and the implementation of this scheme would effectively make them self sufficient on renewal stormwater resources. In addition, the injection of cleansed water into the aquifer will have an immediate pressure improvement and long-term salinity reduction.
From the perspective of natural resource management in the built urban environment this scheme provides an opportunity for the delivery of triple bottom line outcomes that are consistent with the State Government’s water management agenda for Water Proofing Adelaide.
Environmental benefits are significant and include:
- a reduction in polluted stormwater inflows to West Lakes, the Port River and ultimately the Gulf St Vincent;
- a major reduction in use of the locally stressed aquifer;
- an immediate pressure improvement and long-term salinity reduction in the local aquifer; and
- an increase in biodiversity and an opportunity to recreate native aquatic habitats.
Social benefits include:
- reinforcement of community awareness of water conservation issues;
- an opportunity to increase community awareness biodiversity issues;
- improved amenity and visual aspect to Frederick Road, a major arterial to the West Lakes commercial and sporting precinct; and
- the opportunity to demonstrate best practise in environmental protection and water conservation to the local, state, national and international community (via the Club’s high profile event calendar).
Economically, the benefits of the scheme are:
- a sustainable water supply and secured long-term future for one of Adelaide’s premier sporting venues; and
- an aesthetic asset that increases the amenity of the Grange Golf Club adding to its value as a venue for national and international golfing events; and
- ultimately economic benefits by avoiding the fallback to reticulated supply (River Murray) when the aquifer eventually reaches salinity limits for turf application.
The Torrens Catchment Water Management Board considers this scheme to be a beacon in the achievement of a number of goals in its 2002-2007 Catchment Water Management Plan. The Grange Golf Club is a major urban location identified in the Catchment Plan for actions related to a number of strategies:
- the construction of wetlands at strategic locations for water quality improvement;
- the facilitation of viable reuse opportunities and water conservation practices;
- the coordination of integrated stormwater and floodplain management;
- the protection and enhancement of aquatic habitat; and the fostering of an informed, committed and involved community.
The Grange Golf Club Wetland and ASR Scheme has been instigated by a private organisation and they are committed to providing a significant proportion of the capital in addition to undertaking all ongoing maintenance. Whilst this may appear to be self-serving, the fact is that all large-scale reuse schemes must have a captive and guaranteed end customer.
In 2003 the Torrens Catchment Water Management Board and the Grange Golf Club jointly committed $70,000 to a comprehensive feasibility study that determined the technical feasibility and the preferred option for scheme layout. Since this time groundwater modelling and wetland functional design work has been undertaken towards detailed design.
The Project Management, Design, Documentation, Contract Management and Supervision is currently out to tender and will be undertaken over the next four months. The construction of the scheme is scheduled for summer 2005/06 and the commencement of recharging the aquifer during the winter of 2006, subject to financial support and all appropriate approvals. The net present value (NPV) of the scheme (capital and ongoing operational costs) is approximately $3,100,000 of which the Grange Golf Club’s contribution will be $1,600,000 (capital and ongoing costs) and the Torrens Catchment Water Management Board contributing $750,000. $250,000 has been approved from the Catchment Management Subsidy Scheme for works during 2004/05 with the approval of $500,000 for 2005/06 currently awaited to ensure construction can be commenced.
This scheme will target urban Adelaide’s biggest single recreational groundwater irrigator in an area of significant groundwater overuse. With the very limited open space available in the developed catchments of urban Adelaide the completion of this project would send a strong message to all golf courses and similar large landholders with irrigation requirements that they have a responsibility for the sustainable use of water resources and the use of their land for greater good of wider community.
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