Protection of South Africa’s most important water source areas is critical for a water-safe future and the reason why the CSIR and partners embarked on a research project supported by the South African Water Research Commission (WRC). In October, CSIR experts met with their private sector counterparts, as well as senior planners and policy makers within government departments, to finalise the delineation of South Africa’s national strategic surface and groundwater source areas.

Strategic water source areas supply a disproportionately high amount of the country’s water in relation to their size. In the first phase of the research, scientists used rainfall data to map the areas that produced most of the country’s surface water – the water in streams, rivers and wetlands.

“The surface-water strategic water source areas occupy just 8% of South Africa’s land area, yet provide 50% of our water. This water supports at least 50% of the population, 64% of the economy and about 70% of the irrigated agriculture,” says Dr David le Maitre, an ecologist and hydrologist at the CSIR.

“In the second phase of the project, we looked at mapping groundwater sources such as aquifers and boreholes. These data sets will now be included in an integrated and updated report that is being finalised.”

Threats to these catchments include contamination and damage through mining, agriculture and urban development and the researchers discussed the importance of including all South Africans in their management and protection. Therefore the project will produce recommendations for water and land management for government officials, industries and land owners located in these areas.

In refining the areas, the researchers did not simply look at high rainfall areas or size, but at indications that a specific source was of strategic importance, for example the Upper Vaal, Upper Usutu and Waterberg catchments that provide essential water to towns, mining, agriculture and power stations.

“We looked at links to major urban centres, where irrigation water comes from and at areas where systems are already stressed, such as the Vaal. In the Western Cape, a lot of water comes from relatively pristine catchments, but the area faces severe droughts as a result of weakening cold fronts.”

Helen Seyler from Delta H Water System Modelling presented on the delineation of groundwater areas. A total of 124 000 km2 (or 10% of South Africa) was identified as strategic groundwater areas. The researchers included areas where groundwater availability is particularly important for towns and rural areas to function. The researchers also found that nearly all of the 22 strategic surface water areas derive more than 30% of their water from groundwater, but many do not overlap with surface water areas.

She emphasised that groundwater sources are not limitless. Threats include coal mining, petroleum extraction, fracking and changes in land cover and over-use.

For example, the impact of urbanisation needs to be considered in areas such as the Cape Peninsula and Cape Flats where 60% of groundwater sources are located under urban areas, including informal settlements (13%) and industrial and commercial areas (11%). In the country’s northwest, strategic groundwater sources in Kamieskroon, Carnarvon, Port Nolloth, the Komoggas Cluster, and Vanrhynsdorp are facing high drought risk. Mining is a risk to groundwater sources in areas that include Natalspruit, Springs, Klerksdorp, Orkney, Stilfontein and Hartbeesfontein karst regions. These are characterised by aquifers formed from the dissolution of soluble rocks such as dolomites and are vulnerable to pollution. Coal reserves cover 24% of the Eastern Karst belt, where groundwater is also vulnerable.

At the workshop, the experts agreed on the delineation of strategic water source areas that might be further refined later should it become necessary for regulatory reasons. Legal experts said that there are regulations in place to manage and protect South Africa’s water sources, but that these are not always implemented everywhere and might need to be adapted to specifically regulate activities around the delineated areas in future.

According to CSIR environmental assessment practitioner Annick Wallsdorf, the primary principle of the guidelines will be to protect the quantity and quality of the water produced in the strategic water source areas by maintaining or improving the condition of these areas.

The strategic water source areas maps will be used in land and on water use decision-making, for example on proposed developments, water-use licensing and rezoning applications. They will inform proactive conservation and rehabilitation initiatives including expansion of protected areas, biodiversity and water stewardship, the clearing of invasive alien plants and the rehabilitation of degraded land and wetlands. The map will also guide strategic planning, which includes the country’s national water resource strategy, integrated and spatial development and environmental management.

The final technical report, guidelines and information for the public will be published by the WRC during 2018. There will be follow-up work with government departments, including the departments of Water and Sanitation and Environmental Affairs, provincial conservation agencies, the South African National Biodiversity Institute and WWF to ensure that these areas are integrated into policies and plans and properly protected.