Strategic Water Source Areas (SWSAs) are national ecological infrastructure assets that are essential for water security. These areas of high rainfall make up just 10% of the land area of South Africa, Lesotho and Eswatini but supply 50% of water to these countries.

What happens within the boundaries of SWSAs has an impact on water quality and quantity for millions of people and for economic and agricultural activity downstream. A newly released publication from Statistics South Africa (Stats SA), on which SANBI was technical lead, provides insight into land use and protection levels in these strategically important national assets over the past three decades.

The accounts are available on the Stat SA website.

SWSAs are formally defined as natural source areas for water that supply disproportionately large volumes of water per unit area and that are considered of strategic significance for water security from a national planning perspective. Water from SWSAs feeds our major dams, and they can be considered ecological infrastructure that works hand in hand with built infrastructure for delivering water.

The Accounts for SWSAs, 1990 to 2020, released on 30 March 2023, show that while SWSAs occupy only 8% of South Africa’s land area, more than 14% of the population lives within them, ranging from 2 643 people in Waterberg SWSA to 1 324 309 people in Southern Drakensberg SWSA (based on the 2011 Census).

Spread across the country, the 22 SWSAs are economically important areas that vary considerably in context and socio-economic activity. In some cases, the economic activities and land uses within SWSAs can impact negatively on the ecological condition of rivers, wetlands and their associated catchments in SWSAs, with implications for water quantity and quality downstream. Intensive land uses in SWSAs include timber plantations, commercial field crops, orchards and vines, subsistence agriculture, mining and urban settlements, which together made up 29% of the total area of SWSAs in 2020. Nearly a fifth of the extent of SWSAs was formally protected in 2020, compared with 9% of South Africa’s terrestrial mainland.

Understanding the context of a particular SWSA is essential. It is particularly important for informing action to secure SWSAs, including actions to better manage SWSAs, avoid or reduce negative impacts where possible, and restore land and ecosystems in SWSAs where necessary.

The publication profiles all 22 of South Africa’s SWSAs for surface water in relation to the biomes, provinces, district municipalities and Water Management Areas over which they fall. It also gives population statistics for SWSAs, and accounts for changes in land cover and protected areas within SWSAs over three decades from 1990 to 2020. Change is reported for all SWSAs combined and then for each SWSA individually, divided into three accounting periods: 1990 to 2014, 2014 to 2018, and 2018 to 2020.

This information is relevant to several national policies. The National Spatial Development Framework (NSDF) identifies SWSAs as key components of the National Ecological Infrastructure Network. It highlights the need to manage and restore SWSAs for the socio-economic benefits they provide to people, cities and economies in regions they are located and those they supply water to.

The Medium-Term Strategic Framework (MTSF) of the Department of Environment, Forestry and Fisheries (DFFE) includes a target related to securing eleven of the twenty-two SWSAs by 2024. The National Water Resource Strategy 3 (NWRS 3) of the Department of Water and Sanitation (DWS) has prioritised action around SWSAs. Natural capital accounts such as these accounts for SWSAs strengthen the evidence base for government planning and action, helping to ensure it is based on the best available science and data.

Each SWSA has its own story to tell, with different planning and management implications. According to the publication, at the end of 2020, 19% of the total area of all SWSAs combined was formally protected by various types of protected areas, such as National Parks, Nature Reserves, Forest Wilderness Areas and Mountain Catchment Areas.

The proportion protected varied across SWSAs, from 1,1% protected in Eastern Cape Drakensberg SWSA to 76,5% protected in Swartberg SWSA. Focused efforts to expand protection in those SWSAs that currently have very little protection, including through biodiversity stewardship contracts that involve landowners and land users in SWSAs, can pay dividends in terms of securing water quantity and quality into the future.

SWSAs also vary in the proportion of natural vegetation that has been converted to intensively modified land cover classes such as mining, timber plantations, commercial crops or urban land cover.

The proportion of intensively modified land cover varied across SWSAs, from less than 1% in Kouga SWSA to 51% in Upper Usutu SWSA. Where a large proportion of a SWSA has been converted to intensively modified land cover classes, its ecological functioning is likely to be compromised, which has implications for its ability to support water security.

In Upper Usutu SWSA, timber plantations, which are considered a “streamflow reduction activity” by DWS, i.e. an activity that uses a lot of water, were the largest intensively modified land cover class, covering 40% of its area in 2020.

Working closely with the forestry production sector in this SWSA would be key to avoiding and minimising the negative impacts of timber plantations on water security. Upper Vaal SWSA had the highest proportion of commercial field crops of all SWSAs in 2020, covering 28% of its area. Engagement with the agriculture sector and commercial farmers in this SWSA, for example to ensure that there are buffers of natural vegetation between cultivated areas and rivers that pesticide and fertilizer run-off into rivers is minimised, would be an important contribution to water security.

SANBI is playing a leading role in efforts to secure SWSAs, including engaging with municipalities to support them in integrating SWSAs in their planning and decision making, for example through municipal Integrated Development Plans and Spatial Development Frameworks.

For further reading:

  1. Accounts for SWSAs, 1990 to 2020 discussion document PDF D0401.3
  2. Key findings from the Accounts for SWSAs
  3. Stats SA data story about the release of the Accounts for SWSA, 1990 to 2020
  4. Main publication page for Accounts for SWSAs, 1990 to 2020 D0401.3,

For more information contact: Aimee Ginsburg

To arrange media interviews contact:

Editors Notes:

The Accounts for SWSAs, 1990 to 2020 were published by Stats SA, in collaboration with SANBI and the Department of Forestry, Fisheries and the Environment (DFFE), as the third discussion document in Stats SA’s Natural Capital series. They were compiled through the Ecological Infrastructure for Water Security (EI4WS) Project, which is funded by the Global Environment Facility, implemented through the Development Bank of Southern Africa, and executed by SANBI in partnership with DFFE, DWS and other partners.

Note that the figure of 10% in the opening paragraph is 10% of the combined area of South Africa, Lesotho and Eswatini, while the figure here is 8% of just South Africa’s land area.

Scroll to top