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

WMA 13: Upper Orange - Rainfall and Evaporation

WMA 13: Upper Orange - Base Map

WMA 13: Upper Orange - Land Use

WMA 13: Upper Orange - Sectoral Water Requirements (2000)

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

WMA 13: Upper Orange - Water Availability (2000)

WMA 13: Upper Orange - Water Reconciliation (2000)

WMA 13: Upper Orange - Population scenarios

WMA 13: Upper Orange - Water Reconciliation (future)

WMA 13: Upper Orange Groundwater No large porous aquifers found in WMA Relatively large quantities of groundwater abstractable from fracture zones at dolorite intrusions - recharge rates low over most of WMA In drier parts of WMA groundwater constitutes main (and in many cases only) source of water for rural domestic supplies and stock watering Severe over-exploitation of groundwater in some peri- urban areas (also at Petrusburg in Riet / Modder sub- area) due to increasing irrigation from groundwater Although proportionately small component of water available in WMA, it constitutes the main source of water in much of the rural areas.

WMA 13: Upper Orange Water quality In natural state quality of surface water in WMA is good, particularly water from Lesotho Highlands Irrigation return flows has major impact on salinity in lower Riet River - water transferred to Riet River from Vanderkloof Dam for blending and water quality management purposes Natural pan below Krugersdrift Dam adds salinity to Modder River Water quality in Lower Riet River is of concern - also impacts on water quality in Lower Vaal River and at Douglas Weir Quality of groundwater is good in eastern high rainfall parts

WMA 13: Upper Orange Key issues Yield from Upper Orange WMA by far largest of all WMAs in the country Significant potential for further water resource development Main source of water for Lower Orange WMA (including Namibia) and for Fish to Tsitsikamma WMA LHWP has major impact on water availability in Upper Orange WMA Fluctuating releases from hydropower turbines impact negatively on some users. Upstream water transfers negatively impact water availability for power generation

WMA 13: Upper Orange Key issues (2) Hydropower generation at Gariep and Vanderkloof Dams forms important component of Eskom’s peak generation capability Surplus water available in WMA and will in future be after completion of Mohale Dam Over-exploitation of groundwater experienced in localised areas Needs for increased future water transfers to Upper Vaal and Fish to Tsitsikamma WMAs Flood management of major importance for protection of developments along Lower Orange River

WMA 13: Upper Orange Water resources under control of the Minister Transfer out of water from Senqu River in Lesotho to Upper Vaal WMA Transfer out of water from Marksdrift to Douglas Weir (Lower Vaal WMA) for water quality purposes Transfer out of water to Fish to Tsitsikamma WMA (Orange-Fish transfer) Release of water to meet needs in Lower Orange WMA and for Namibia Current reservation of water for hydropower generation by Eskom for peak clipping purposes Large scale water resource developments on Orange, Caledon and Kraai Rivers subject to authorisation at national level