Objective: Minimise the use of potable water and promote conservation of water resources
Water conservation and water demand management should be implemented through efficient technologies and behavioural changes. The aim is to reduce water consumption, specifically potable (drinking) and groundwater, through the use of efficient fixtures, controlled irrigation and public awareness.
The use of rainwater and greywater is encouraged wherever possible, as well as the protection of water resources through the use of environmentally friendly products to clean stadia and maintain pitches. In creating new construction surfaces, the use of permeable materials for pitches and walkways has also been promoted.
The projects
- Identify alternative sources of water for irrigation of Green Point Common
- Installation of water-saving devices in stadia and training venues
Project progress
Identify alternative sources of water for irrigation of Green Point Common
During the conceptual design phase of the Green Point Common redevelopment, the issue of alternative water sources for irrigation of this 69 hectare open space was highlighted. In 2008, the City of Cape Town (CoCT) commissioned Arcus Gibb to undertake a feasibility study of alternative water sources for irrigation as opposed to the use of potable water, which had been used previously. The study investigated among other things desalinisation, feasibility of boreholes, greywater treatment, rainwater harvesting and the harvesting of spring water from the slopes of Table Mountain. The study concluded that the harvesting of spring water from the Oranjezicht Springs was the most cost-effective way to reduce the use of potable water for the irrigation of the Common. The spring water is not potable, and will require treatment to meet drinking water standards.
The history of Cape Town’s establishment as a trading post and refreshment station is directly linked to this source of fresh water from the slopes of the mountain. Over time, the spring water was canalised, and today it is mostly conveyed underground in a series of pipes and stormwater drains, eventually draining into Table Bay. The harvesting of this water for irrigation purposes presents a significant opportunity to elevate the role that water played in the history of Cape Town. The Reclaim Camissa project is working to restore the historical connection between the mountain and the sea, and develop heritage and tourist resources throughout the CBD linked to the springs and rivers on the slopes of the mountain.
Water from Oranjezicht Springs to irrigate Green Point Common
The analysis of alternative sources of irrigation water for Green Point Common, and a comparison of the yields, costs and secondary benefits related to the different options, show that the project making use of water from the Oranjezicht Springs is financially attractive (a third of the cost of using potable water), is sustainable, and will meet the objective of providing irrigation water to Green Point Common for the benefit of all.
This makes water provision to Green Point Common from this historical source, whilst functioning in parallel with the vision of the Oranjezicht Heritage Society, a seemingly win-win solution. Water from the Oranjezicht Springs was the original supply that facilitated the establishment of Cape Town as a replenishment station for shipping in 1652. The use of this spring was formalised in 1682, with a chamber to protect the Main Spring built in 1813. This now presents an opportunity not only to make practical use of this source of water, but also to expand the heritage fabric and tourism potential of Cape Town, as has been highlighted by Caron von Zeil and Colleen Stoltzman of the Oranjezicht Heritage Society.
Arcus Gibb, August 2008. Preliminary Investigation Report – Feasibility Study: the Supply of Irrigation Water to Green Point Common.
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Installation of water-saving devices in stadia and training venues
The environmental Record of Decision (ROD) issued by the Department of Environment and Development Planning (DEADP) on 31 October 2006, and the subsequent ruling on appeals against the ROD on 5 January 2007, called for a number of water-efficiency measures to be incorporated into the design of Green Point Stadium. These include the following:
- Water-efficient fittings on showers, taps and toilets (multi-flush rather than dual flush)
- Water-wise landscaping
- Rainwater harvesting and storage for irrigation and toilet flushing
The following water-efficiency measures were subsequently included in the design of Green Point Stadium:
- Toilets in the special guest areas are fitted with dual-flush mechanisms.
- All taps have self-closing metering valves and aerators, and low-flow showerheads have been fitted.
- The landscaping design favours water-wise, indigenous plants.
- Rainwater and stormwater harvested off the stadium roof, pitch, podium surface and park is directed to a detention pond for reuse for irrigation.
- A natural soccer pitch with artificial matting was specified to help reduce the need for irrigation.
Lessons learnt from water conservation projects
The Western Cape is a water-scarce region, and projections show that pressure on water sources, in particular potable water, will increase as temperatures rise due to climate change. The use of potable water for irrigation has long been questioned by water specialists, and projects that reuse greywater or stormwater are generally welcomed.
In light of this, a project to redirect spring water that is currently not harvested, for irrigation of Green Point Common makes a positive contribution to the Common’s sustainability. The water will also be used to create ponds in the Green Point Urban Park and the metropolitan golf course, which will create opportunities for new habitats and wetlands to be established, recreating some of the seasonal vlei environments that had characterised Green Point Common before it was developed into the sport precinct that we know today.
The initiatives to reduce the amount of potable water used in the new Green Point Stadium further contribute to a reduction in the use and wastage of potable water. An independent panel of green architects appointed by the Department of Environmental Affairs and Tourism (DEAT) recognised the technologies used as best practice in sustainable stadia design.
Key references and source material
- Arcus Gibb, August, 2008. Preliminary Investigation Report – Feasibility Study: the Supply of Irrigation Water to Green Point Common. Reference number R030800196. (Cape Town, South Africa). Commissioned by the City of Cape Town.
- Urban Environmental Management Programme and Green by Design WSP, 2008. 2010 FIFA World Cup Green Point Stadium: Environmental Performance Enhanced. (Pretoria, South Africa). Commissioned by Department of Environmental Affairs and Tourism, funded by the Royal Danish Embassy, South Africa.