Are we standing on the solution: Is groundwater a new gold mine?

Welcome back! This third blog post explains why groundwater is a useful tool for accessing safe water in Africa, particularly in the context of climate change, with a specific focus on Tanzania. 

Groundwater is the world's largest accessible store of freshwater, supplying over 30% of the world's drinking water today (Taylor et al., 2013). However, the rates of groundwater level decline have increased substantially, leading academics to question the relationship between precipitation and recharge. Groundwater is naturally a potable quality and, therefore, does not require expensive treatment, which lowers the cost of access (Taylor et al., 2009). It is typically stored in aquifers, which vary dramatically in shape and size. As they are underground, they are protected from the dangers of evaporation, something that climate change is intensifying. 

Africa is extremely rich in water. That is a statement you may not hear frequently, but it is true. The water is just stored underground, and chronically underfunded services make it hard to access. There is actually enough water underneath Africa for most countries to survive 5 years of drought, with some nations able to survive up to 50 years. Not only this, but every Sub-Saharan nation could supply 130 litres of drinking water per capita per day only from groundwater. This is enough groundwater to be able to transform agriculture in the region and provide adequate water for drinking and hygiene needs; if managed correctly. 

Figure 1: A hand pump in Tanzania

This leads me to discuss Tanzania as a case study. Generally, Tanzanian groundwater is considered to be of good quality and acceptable for use. It is accessed via boreholes with either electric or hand pumps, as pictured in Figure 1. Currently, across Tanzania, groundwater is used for urban water supply (10%), rural water supply (50%), agriculture (10%), and industry (2%). According to the Intergovernmental Panel on Climate Change, climate change has the potential to degrade groundwater availability, water quality and water supplies (Neyembo et al., 2022). To ensure the sustainable use of groundwater resources in Tanzania, a national groundwater database needs to be established to monitor water quality, extraction and recharge with regular updates (Ligate et al., 2021). The projected shift towards a wetter El Niño period, with more regular, intense monthly rainfall, would appear to favour groundwater usage through sufficient recharge. Although, land cover is just as important as rainfall in terms of 'rechargeability'. This can be encouraged through afforestation and the prevention of land clearing to naturally create permeable surfaces, stabilising soil and generally slowing the flow of water. 

So, is groundwater a potential gold mine? Personally, I think it provides a realistic and relatively simple solution to physical water scarcity and access to safe and clean water. However, it must be monitored and governed in a sustainable manner, or else the situation will be back to square one. Stay tuned as next time I delve deeper into technological solutions to the conundrum of water, development and environmental change.