Water Wheel March/April 2020: Water Ecosystems

Abstract

The slow death of Lake Sibaya Lake Sibaya, named after the Zulu word for cattle kraal, is the country’s largest coastal freshwater lake. With a surface area of more than 60 km2 and a water depth of 41 mat the deepest point, it has been estimated that Sibaya can hold more water than all three large dams in the uMngeni River system (Midmar, Albert Falls and Inanda dams) or about 44% of the Pongolapoort Dam. The lake was once an ancient river estuary, before it was cut off from the Indian Ocean by the gradual formation of a coastal dune barrier. Located in the northern part of KwaZulu-Natal, about 60 km south of the Mozambique border, Sibaya lies on a flat coastal plain where most of the surrounding landscape rarely rises more than 100 m above sea level. But beneath the region’s largely infertile and sandy soils there is a vital groundwater aquifer which has helped to sustain local communities and the ecology around Lake Sibaya for millennia. As part of this aquifer, the lake is an almost direct reflection of the regionally-important groundwater table.

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