An updated water balance for the Grootfontein aquifer near Mahikeng

Authors

  • JE Cobbing AEON/ESSRI: Africa Earth Observatory Network / Earth Stewardship Science Research Institute, Faculty of Science, Nelson Mandela University, Summerstrand, Port Elizabeth, 6031, South Africa

DOI:

https://doi.org/10.4314/wsa.v44i1.07

Keywords:

Groundwater, North West dolomites, Mahikeng, over-abstraction, irrigation

Abstract

The Grootfontein Aquifer, part of the important North West dolomite aquifers, supplies about 20% of Mahikeng’s domestic water needs. Over-abstraction caused the large natural spring draining the aquifer to disappear in 1981, and groundwater levels have since fallen nearly 30 m in the vicinity of the former spring. Analysis of water levels and a water balance using recent assessments of groundwater abstractions confirm past work describing the hydrogeological functioning of the aquifer, and suggest that current abstractions need to fall by between 19 and 36 ML/day (7 and 13 Mm3/a) to bring the aquifer back into longterm balance. Continued over-abstraction at Grootfontein implies increasing risk to Mahikeng’s water supply, and illuminates the larger challenge of ensuring groundwater use in the North West dolomites that is sustainable and in the public interest.

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Published

2018-01-31

Issue

Section

Research paper

How to Cite

Cobbing, J. (2018) “An updated water balance for the Grootfontein aquifer near Mahikeng”, Water SA, 44(1 January). doi:10.4314/wsa.v44i1.07.