7.2 The Source Water

The source water is from a local ephemeral river. Although there is no visible flow in the river for most of the time, it does experience flooding events from time to time. Because such floods carry a significant sediment load, filtration of debris and clay is necessary before injection into a borehole.

Small-Scale Water Supply in a Semi-Arid Area

The village depends solely on groundwater, pumped from the municipality’s three abstraction boreholes. Natural groundwater recharge is very low and as a result of abstraction since the mid-1990s, groundwater levels had dropped tens of meters and the water quality (salinity) had deteriorated significantly. The aim of artificial recharge is to reverse this negative trend by rapidly replenishing the aquifer when river runoff is available. This action significantly increases the borehole yields and improves water quality. People living in this remote, arid area depend on the functioning of this scheme.

One of the key management functions of any MAR scheme is to avoid clogging, the potential for which is especially high in borehole injection schemes. Schemes in primary aquifers – those made up of unconsolidated sand – are not as susceptible to this problem because they normally rely on infiltration to get the recharge to the aquifer. The scheme at Kharkams includes a sand filter that is built in the bed of the river. Most of the water, when available, flows over and past the filter, but some infiltrates the sand filter and flows to the injection boreholes (Murray, 2004).


Managed Aquifer Recharge: Southern Africa Copyright © 2021 by Eberhard Braune and Sumaya Israel. All Rights Reserved.