Geoethical Issues Around Water-Security for Cape Town and Groundwater Resilience in Uncertain Circumstances

Abstract

In early 2018, Cape Town faced “Day Zero,” the date when it was expected to run out of water, and when all municipal supply would be rerouted to emergency collection points. A three-year drought, considered ~1-in-400-year hydrological event, had brought the level of its largest storage reservoir to around 11% of full capacity. Day Zero was averted by relatively good rainfall early in 2018. Two years on, water-security remains precarious and uncertain in the face of rapid urban expansion, slow environmental degradation, and long-term climate change. The wider catchment region contains two important subsurface resources: the Palaeozoic Table Mountain Group (TMG) Aquifer System, and the Cenozoic Cape Flats Aquifer (CFA). The development of these groundwater options is confronted by challenges related to environmental and societal impacts. In the case of the TMG resource, which underlies mountain biosphere reserves of the extraordinary Cape Floral Kingdom, geoethical concerns arise in the context of uncertainties related to anticipated impacts on stream flow and floral biodiversity. In the CFA case, geoethical issues revolve around uncertainties related to impacts on the coastal environment, the groundwater–seawater interface, and the power-generation costs of groundwater management and treatment under constraints imposed by South Africa’s fossil-fuel dependence.