Groundwater as an Alternative?

MacDonald et al (2009) describes surface water as becoming increasingly unreliable, and it is because of this that we need to look elsewhere for more resilient and sustainable water supplies. Groundwater is responding to this need as a ‘reliable and flexible irrigation supply’ (Villholth 2013: 369) and is perhaps the most promising alternative to surface water. Taylor et al (2009) goes into a substantial amount of detail surrounding groundwater, clearly outlining the pros and cons of this resource. One of the main advantages of using groundwater is down to it being the largest store of freshwater on the planet, therefore it makes sense to use this store as opposed to the increasingly variable surface water supplies. This is especially true in arid and semi-arid regions of Africa where increased evapotranspiration and decreased or delayed precipitation as a result of climate change has already left some communities completely absent of surface water all together. Groundwater on the other hand is proven to be a more reliable source than surface water, due to it’s ability to be maintained and stored in aquifers during periods of little or no rainfall (MacDonald et al 2011). However, the sustainability of groundwater remains unclear (Taylor et al 2009), as explained in Edmund’s (2009: 781) paper where it is stated that ‘the non-renewability of many groundwater sources [are] now being exploited across the arid and semi-arid regions of Africa’, therefore the ability of groundwater to alleviate water scarcity also remains unclear.

The results from a study on groundwater recharge in Tanzania allow me to end this blog on a more optimistic note. Taylor et al (2013) found a non-linear relationship between recharge and rainfall, where it was shown that intense precipitation contributed to recharge at a disproportionate rate. As explained in an earlier blog post, many parts of Africa are expected to experience more intense precipitation as a result of climate change. Therefore, the associated increase in recharge should subsequently sustain groundwater levels for future use, providing Africa with a feasible adaptation to the increased variability in surface water.