NATIONAL WATER RESOURCE STRATEGY SOUTH AFRICA’S WATER SITUATION AND STRATEGIES TO BALANCE SUPPLY AND DEMAND MIDDLE VAAL WMA

WMA 9: Middle Vaal - Rainfall and Evaporation

WMA 9: Middle Vaal - Base Map

WMA 9: Middle Vaal - Land Use

WMA 9: Middle Vaal - Sectoral Water Requirements (2000)

Sectoral contributions to the economy (1997) Contribution Agriculture Mining Manufacturing Electricity Construction Trade Transport Finance Government Other Community 0 % 20 % 50 % 40 % 30 % 10 % National Middle Vaal WMA

WMA 9: Middle Vaal - Water Availability (2000)

WMA 9: Middle Vaal - Water Reconciliation (2000)

WMA 9: Middle Vaal - Population scenarios

WMA 9: Middle Vaal - Water Reconciliation (future)

WMA 9: Middle Vaal Groundwater Large dolomitic aquifers in northern part of WMA Water from aquifers abstracted for urban use at Ventersdorp as well as for irrigation and rural water supplies Substantial quantities also processed as bottled water The remainder of the WMA mostly underlain by fractured rock aquifers - well utilised for rural water supplies and with little undeveloped potential remaining About 11 million m 3 per year pumpage from de-watering of mines in Welkom-Virgina area evaporates from pans

WMA 9: Middle Vaal Water quality Naturally quality of surface water in WMA area is good High salinity and nutrient content as result from urban and industrial return flows and mining activities Pollution of groundwater due to chemical reaction when mining operations are discontinued Quality of groundwater over remainder of WMA generally of a very high standard Water quality management in the Vaal River expected to become of increasing importance

WMA 9: Middle Vaal Key issues Because of location between Upper Vaal and Lower Vaal WMAs water availability along Vaal River is inextricably linked to these WMAs and to water resource management in Vaal River system Middle Vaal WMA dependant on releases from Upper Vaal WMA for meeting bulk of requirements Water quality in Vaal River is of serious concern because of high salinity and nutrient content which mainly results from urban and industrial return flows and mining activities in Upper Vaal WMA - closure of mines may have further water quality impacts

WMA 9: Middle Vaal Key issues (2) No control structures with respect to regulation of flow in Vaal River within Middle Vaal WMA and both quantity and quality of water in Vaal River largely influenced by management practices in Upper Vaal WMA Water from tributaries and from groundwater in WMA fully utilised (mainly for irrigation and for towns remote from Vaal River)

WMA 9: Middle Vaal Water resources under control of the Minister Transfers from Upper Vaal WMA for use in Middle Vaal WMA and downstream Transfers from Middle Vaal WMA to Lower Vaal WMA Small existing transfers for domestic use -from Vaal Dam (Upper Vaal WMA) to Heilbron (Middle Vaal WMA) -from Erfenis Dam (Middle Vaal WMA) to users in the Upper Orange WMA