Integration goes underground: A review of groundwater research in support of sustainable development in South Africa

Abstract

The groundwater group of the CSIR has led groundwater research in South Africa in three critical areas during the last three decades: nitrates in groundwater; groundwater for ecosystems; and artificial storage and recovery of groundwater. Over a third of the rural population of South Africa is dependent on groundwater resources for household and agricultural use. South Africa has some of the highest natural nitrate levels in the world (>500 mg/L N-NO3). The group has researched the distribution of high nitrate groundwater in the Kalahari to understand why it is concentrated here. Current research is focussing on an in-situ barrier treatment to reduce nitrate levels in the water before it is pumped from the aquifer. This will help to limit the exposure of vulnerable bottle-fed infants and livestock to nitrate toxicity. If we are to use groundwater sustainably in the future we need to understand how ecosystems rely on natural flows of groundwater to springs, rivers and wetlands. Aquifer dependent ecosystems are often important in sustaining surrounding ecosystems. The groundwater group has developed guidelines for their identification and protection within catchment management. These should help to protect rural livelihoods that depend on ADE goods and services .Aquifers store huge volumes of water and act as nature’s dams: groundwater accounts for around 95% of available, usable freshwater. This storage can be enhanced by infiltrating or pumping water into aquifers, reducing the evaporation losses experienced in surface water dams. The groundwater group has pioneered the use of artificial storage and recovery of groundwater (ASR) in the Atlantis aquifer (Cape Town) and the Windhoek aquifer (Namibia). These are the first ASR sites in Africa and are used effectively in water supply to these water-stressed areas