Geoethics of Bulk Groundwater Abstraction in an Ecologically Sensitive Area: Steenbras Wellfield (Cape Town)

Abstract

The City of Cape Town initiated its “New Water Programme” in 2017 to diversify its bulk water supply, thereby improving long-term water security and resilience against future droughts—this includes bulk groundwater abstraction of potentially ~140–400 Ml/day from the major fractured Peninsula and Nardouw Aquifers of the Table Mountain Group (TMG; in the mountain catchments to the east of the city). Current TMG groundwater exploration and wellfield development are taking place in the vicinity of Steenbras Dam, in the form of the ~15–20 Ml/day Steenbras Wellfield scheme. The TMG aquifers are also essential in sustaining groundwater-dependent ecosystems associated with the Cape Floral Kingdom—a global biodiversity hotspot with exceptional endemic diversity, but also a global extinction hotspot. A strong geoethical, “no-regrets” approach is, therefore, required to develop TMG wellfield schemes for the City of Cape Town (and other towns/cities in the Western/Eastern Cape), in order to reduce the risk of any negative ecological and environmental impacts, while still enhancing the drought resilience of the city, providing water for future urban growth, and meeting Sustainable Development Goals 6 and 11.