‘Tap into groundwater – with care’
The Southern African region has vast groundwater resources, but only 1.5% is being used
For James Sauramba, the key to building water resilience in Southern Africa lies right under our feet: groundwater.
“Climate change is intensifying,” says Sauramba, the executive director of the Southern African Development Community Groundwater Management Institute. “The rivers are drying up, the rivers are turning into sand and the dams are drying up.”
The latest report of the Intergovernmental Panel on Climate Change warns how this could worsen. Southern Africa, a dry, hot and semi-arid region, is likely to become drier with reductions in precipitation and droughts becoming more frequent at 1.5°C of global warming and higher, deepening water scarcity.
“The way we see it is that groundwater by its very nature is underground and less exposed to the risks of evaporation and pollution and so forth, therefore it’s the more resilient of the two twins of groundwater and surface water,” Sauramba said.
He was speaking during World Water Week, which was held last week under the theme of “Building resilience faster”, which recognises the need to find solutions to counter climate change and other waterrelated challenges.
“We have groundwater to depend on. And that increased dependency on groundwater due to climate change means we have to obviously do more to ensure that we wisely and sustainably explore the groundwater resources we have in conjunction with surface water.”
One solution is managed aquifer recharge, he said. “This is an approach where surface water resources are injected into aquifers and then abstracted at an opportune time to manage the gap between the absence of surface water and the availability of groundwater.
“You have to inject the right quality of water into the aquifer and also have to do sufficient analysis of the boundary conditions of the aquifer so that we don’t pump in the water and then it disappears again.”
Windhoek successfully uses managed aquifer recharge during wet seasons. “When they have enough water in dams, they purify that water, and inject it into the aquifer and during dry periods they use that water. They pump it out again.
“It’s a costly exercise — you have to be very aware of where you are pumping and the right quality of water. When water is in an aquifer and it gets polluted, it’s very difficult to eradicate or remove the pollution. It’s important to get the right quality of water in the aquifer for use in the future.”
The Southern African Development Community (SADC) boasts huge groundwater reserves, but is only tapping into about 1.5% of this. “When a new settlement is developed, people just look at where the next river is. They don’t say: ‘Okay, where is the next water resource’.”
About 70% of the region’s 280-million inhabitants rely on groundwater, especially in rural areas. For these people, this source of water is often the “difference between life and death”, he said.
“With the impacts of climate change as they are, it means a lot of people are insecure in terms of water and food security.”
An August 2020 assessment report by SADC’S Groundwater Management Institute sought to bring the role of groundwater in securing water supply during droughts to the fore and provide proactive planning, recommendations and management of groundwater and surface water systems.
It identified 13 hotspot areas in the region where pressures arising from population growth, human settlements, pollution, drought and the absence of surface water, converge.
In South Africa, three priority areas prone to drought are the southwestern tip of the country, including the Western Cape, the north-eastern region, including Gauteng, and the region below Lesotho.
In a recent opinion piece, Sauramba lamented how, in the SADC, there is a regional trend of pilot projects, “which remain piloted projects year after year”.
“We can’t afford to have designs that gather dust. We have pilots that demonstrate the viability of certain innovative principles and methodologies that have not reached the level of being upscaled or replicated. This means they don’t reach the point of application where they could contribute to water security for communities’ livestock, industrial development and other human settlement activities that support livelihoods.”
Sauramba said people are integral to the sustainable use and protection of groundwater. “What tends to happen is you have projects implemented by development partners, including government ministries and departments, that in many cases disregard citizen-science knowledge.
“In the end, you find pumps are installed and then they drain the groundwater, which historically people only used in small wells … Some of that groundwater has been recharged over millions of years. It’s very important to understand how that aquifer exists, how it is recharged, the pollution zones as well as the sustainable yield.”
Groundwater, he said, can help improve regional food security. Of the 83% of the region’s water resources pumped into agriculture, just 12% arises from groundwater.
“We need to enhance our water security to be able to secure our food security in the wake of climate change. We really need to boost our ability to use groundwater, which we have an abundance of. There are areas where it’s over-abstracted, and other areas where groundwater is not used at all, but it’s about a holistic picture of using this important resource.”