Parched prospects II: a revised long-term water supply and demand forecast for South Africa

Parched prospects II: a revised long-term water supply and demand forecast for South Africa

It is likely that South Africa is overexploiting its water resources at the national level, as water withdrawals currently exceed reliable supply. using the international futures forecasting system, this paper forecasts that withdrawals in all three sectors (municipal, industrial and agricultural) will increase over the next 20 years. Proposed interventions for increasing supply and reducing demand are not enough to reconcile the gap between withdrawals and supply. More must be done to bring the South African water sector into balance and reconcile future national water withdrawals with future national supply.

The large-scale water-reconciliation strategies analysed for this research plan to increase national water supply by nearly 2.5 km 3 by 2035. Much of this increase in supply will come from the construction and raising of dams to increase reliable surface-water yield. these interventions are necessary, as water demand is growing rapidly. Even with the successful implementation of these interventions, however, the demand forecasts explained in this paper indicate that withdrawals will exceed reliable supply every year through to 2035. this means that additional interventions on top of the large- scale reconciliation strategies will be required to bring withdrawals and supply into balance.

This paper makes the following recommendations:

  • all of the planned interventions outlined in all of the large- scale reconciliation strategies must be completed on time
  • groundwater is an under-used resource in South Africa. research indicates that the main constraint on groundwater use is not the availability of the resource but problems related to operation and maintenance
  • only 54% of municipal wastewater is treated in South Africa and nearly a quarter of wastewater treatment facilities are in a critical state. Growing municipal water demand will translate into growing municipal wastewater, and facilities must be put in place to treat this wastewater. This will increase the overall supply of water in South Africa along with water quality
  • there is significant room for improvement in terms of WcWDM. This can be achieved by reducing non-revenue water and by reducing per capita water use
  • setting and achieving the necessary targets to close the gap between withdrawals and supply require strategic foresight based on plausible forecasts. Strategic foresight is an iterative process, and the forecasts in this paper must be analysed and improved as more data becomes available and assumptions change
  • plausible forecasts require timely data. There is a thriving water-research community in South Africa and an abundance of data, but this data is often not in a standardised format that can be easily analysed. Studies done at the municipal, provincial and catchment levels are not directly comparable because of differences in geographic scope. furthermore, it is difficult to aggregate this data to create a national water balance. More research is required to create a coherent national water balance using all available research at all geographic levels of analysis. this paper is a first step in that direction

 

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