In 2000, the Department of Water Affairs and Forestry hosted two workshops to predict future water demands in the Cape Metropolitan Area (CMA). The projected future water demands for the CMA were considered in terms of potential water savings, historic growth in demand, future urban developments, and agricultural demands. The graph below shows the bulk water supplied by the Western Cape System and the overall water demand curves for the CMA, followed by forecasts with different water resource strategies in place.
There have been at least three major studies over the past 13 years to investigate options for increasing water availability in the Western Cape and the Cape Metropolitan Area (CMA), i.e.:
The Western Cape System Analysis (1989 - 1995)
The Western Cape System Analysis (WCSA) was a wide-ranging, water resources planning study initiated by the Department of Water Affairs and Forestry (DWAF). It assessed the likely future growth of water demands in Cape Town and the surrounding areas and studied options for meeting these demands.
The public evaluation of the WCSA approved the following water supply augmentation schemes for further study, with a view to implementation:
The Table Mountain Group aquifer did not feature as an option during this study - the main reasons being that it was largely unknown, dismissed as having little potential and that the technology to drill for water at such depths (up to 2000 m) was not available.
The Integrated Water Resource Planning Study (1999 - 2001) and CMA Bulk Water Supply Study (2001 - 2002)
(go to download documents for a consolidated summary)
In October 1999, the former Cape Metropolitan Council (CMC) initiated the Integrated Water Resource Planning (IWRP) Study to undertake a pre-feasibility level investigation of alternative options to manage the demand for water in the CMA and to supplement the water supply to the CCT from local sources.
Public meetings held in September 2000 as part of the IWRP Study supported the need to investigate three further supply options (i.e. the Voëlvlei augmentation scheme, desalination and the TMG Aquifer). These options were then investigated in a study entitled the CMA Bulk Water Supply Study (CMA Study) in 2001 and 2002.
The objectives of the two studies were:
Some options, most of which were related to water demand management, were so favourable that they needed no further investigation and were suitable for immediate implementation. Leakage repair and pressure management are two such options which the CCT is currently implementing.
Other options, such as the removal of alien vegetation, agricultural water demand management, and water supply schemes falling outside the CCT's planning authority, were not covered by the two studies.
The Integrated Water Resource Planning Study (1999 - 2001) recommended that two "packages" of options for water demand management and supply be implemented as soon as possible. It also recommended that the construction of the Skuifraam Dam and Skuifraam Supplement (the Berg Water Project), proceed in parallel with the implementation of the other proposed measures.
The first set of options (Package 1) entailed:
The second set (Package 2) entailed:
The combined effect of "packages" 1 and 2 on the overall projected water demand for the City of Cape Town
The IWRP Study also recommended that further supply schemes should be considered as water demand management alone would not enable the system to meet future needs.
The CMA Bulk Water Supply Study (2001 - 2002) followed from the IWRP Study and recommended that the third grouping of options (Package 3) should entail:
The impact of the recommended packages, including the Berg River Project, on overall water demand and supply
The CMA Bulk Water Supply Study states that the investigation of the Table Mountain Group Aquifer would entail utilising the Peninsula Formation at depths of more than 300m below the surface. Potential well field areas include the high rainfall areas of Wemmershoek, Franschhoekberg Tunnel zone, Franschhoek Pass area, Villiersdorp-Brandvlei, Groenlandberg and Voëlvlei. A feasibility study and pilot project would be required to investigate existing knowledge gaps, and potential yields, costs and environmental impacts.Go here for updated information on Water Demand Management in the City.