No mention of groundwater?

A recent article published in Bloomberg titled ‘ “Catastrophe” Seen by S. Africa Agriculture Due to Drought’ caught my eye. South Africa, one of the most developed countries in Africa, is experiencing its worst drought in more than a century. As to be expected, agriculture is being hit hardest. This is exacerbated by the fact that rivers and dams are also running dry and that the drought may well continue into 2017.

The article highlights how the drought is incurring huge financial costs for individuals and businesses in South Africa with the government spending 268 million rand on drought relief. The recent El Niño event caused the drought here and a lack of rainfall since then has halted the recovery from this. This entire article, however, does not mention groundwater what-so-ever despite groundwater being useful during droughts. This encouraged me to look into South Africa’s access to groundwater and the use of groundwater to adapt to climate change.

Figure 1: (a) Groundwater storage measure in water depth (mm) and (b) total groundwater storage by country in Africa

As can be seen from Figure 1, South Africa is not particularly lacking in groundwater storage with eastern areas having around 10,000 – 25,000 mm water depth of groundwater and a reasonable recharge rate of 25-100 mm per year. It is also worth noting that South Africa has more groundwater than around two-thirds of countries in Africa. So now we know that South Africa isn’t lacking in groundwater, why wasn’t it mentioned as an irrigation technique in the Bloomberg article?

The groundwater in South Africa is located relatively shallowly compared to other areas of Africa as shown in Figure 2. This means that it is easier to extract the available groundwater and much greater amounts can be extracted using motorised pumps – as is necessary for irrigation. This gives extra weight to the argument for using groundwater in South Africa and questions why it isn’t being used more.

Figure 2: Estimated depth to groundwater (mbgl)

South Africa’s relationship with groundwater fed irrigation is interesting. As a result of the country’s apartheid history, much of the development and financing for irrigation was focused on White Farmers. This is particularly important as 80.2% of the population in South Africa is Black African. Further to this, irrigated land of White farmers was on average 10 times larger than those of Black farmers. The majority of Black farms are therefore small scale and the irrigation technology was directed to larger scale farms. These statistics help to show that the issues surround irrigation in South Africa are in fact related to the country’s apartheid history and the lack of access to irrigation technology and finances for many Black farmers. To me, this illustrates why South Africa is having such a ‘catastrophe’ with the droughts. The majority of small scale farmers lack groundwater access to keep their crops irrigated during this prolonged dry spell despite the water resources existing in (or under) their country.

Specifically regarding smallholder irrigation schemes in South Africa, just 3.0% of land that required irrigation used groundwater sources. This is incredibly low considering the large groundwater resources that are relatively easily available in South Africa as mentioned earlier. With reduced rainfall and rivers running dry, it is easy to see why crops are dying and small scale farmers are struggling. They simply are unable to access the groundwater beneath their feet that could help them during dry periods like the one they are currently in.

So what does the next year and the future hold for South Africa? Agriculture currently accounts for 85% of freshwater usage and total consumption for agriculture is expected to double by 2050. This increased demand for water alongside climate change is going to have significant impacts on irrigation in South Africa. Figure 3 below highlights that the relative increase in water demand for crops is going to increase more significantly in South Africa than many other areas. With South Africa dominated by a few large commercial farms and numerous small scale subsistence farms, the people of South Africa will be dearly affected by climate change. It is unknown how climate change will impact food production exactly in South Africa but some models predict that under wetter and warmer conditions, welfare in South Africa will increase due to an improved competitiveness in the food market globally. Whether South Africa will get wetter and warmer is again debatable and other future situations see the country far more negatively affected. 

Figure 3: Relative increase in crop water consumption

It is understandable that the Bloomberg article neglected groundwater in the piece on the South African drought due to its relative insignificance as an irrigation technique in the country. It is worth saying however that if the country could provide good access to the groundwater as a source of irrigation, it would improve their resilience to droughts and other impacts of climate change in the future. Personally, I believe that in South Africa’s case, groundwater usage should be limited to instances of extreme drought, and therefore only used sparingly in times of greatest need as the rate of groundwater recharge is low and sustained use could leave the nation short of water.