It is apparent that water could be a crucial limiting factor in social and economic development in the Western Cape. The storage and supply capacity of many surface water drainage basins is stretched to the utmost. It is therefore a matter of urgency that a quantitative approach to water-resource evaluation be pursued to provide an understanding of deep groundwater systems.
The TMG Aquifer study is planned to take place over a five-year period, involving four main phases. The first or Inception Phase has been completed. It entailed constituting the Study Management Committee and Key Stakeholder Forum , reviewing and finalising the detailed Terms of Reference, and selecting the external Peer Reviewers.
The other main phases of the TMG Aquifer study :
Preliminary Phase: This phase focused on the selection of the most favourable target areas for wellfields, based on the regional assessment. Sites for potential exploratory boreholes were selected, after having defined the monitoring requirements and considered all the environmental and other relevant factors.(COMPLETED 2003)
Exploratory Drilling Phase: This phase is intended to verify the requirements and the predicted hydrogeological characteristics of the TMG Aquifer, to obtain more monitoring data, and to refine the siting of the potential pilot wellfield/s.
Pilot Borehole Phase: During this final phase the environmental monitoring will continue and a number of production boreholes will be drilled to develop one or more wellfields with a combined target yield of 3 to 5 million m3/annum.
The project will proceed incrementally, subject to approval of each phase.
Timeline for project
The main phases of the study are as follows:
- Inception Phase: Constituting the Study Management Committee and Key Stakeholder
Forum, finalising the Terms of Reference and selecting the external Peer Reviewers.
- Preliminary Phase: Selection of the most favourable target areas based on the
regional assessment. Sites for exploratory boreholes will also be selected, after having
defined the monitoring requirements and considered all the environmental and other relevant
factors.
Exploratory Phase: Verifying the requirements and the predicted hydrogeological
characteristics of the TMG Aquifer to obtain more monitoring data, and refining the siting of
the pilot wellfields.
- Pilot Phase: Environmental monitoring and drilling of a number of production
boreholes to develop one or more wellfields with a combined target yield of 3 to 5 million
m³/year.
The study will investigate the following critical aspects:
Hydrogeological;
Engineering and drilling;
Infrastructure;
Ecological and environmental;
Societal and legal;
Risk definition; and
Wellfield operation.
The TMG Aquifer study will also be informed by a parallel investigation, commissioned by the Water Research Commission, into the ecological and environmental impacts of large-scale groundwater development in the TMG aquifer system. The ecological and environmental investigation is being conducted by a team led by the Council for Scientific and Industrial Research (CSIR).
