6.3 The Source Water

Source water for injecting into the Windhoek Aquifer (Figure 29) is treated dam water plus reclaimed wastewater.

Photo showing injection borehole site

Figure 29  Injection borehole site with indication of source water (Murray, 2017).

The main source of water supply to Windhoek is the Eastern National Water Carrier, a pipeline that connects the Omatako dam in the north and the Swakoppoort dam in the west with the Von Bach dam located in the central area (Figure 30).

Photos of Von Bach Dam and Swakoppoort Dam

Figure 30  a) Von Bach Dam, Photo by Menges, 2020 in The Namibian. b) Swakoppoort Dam, Photo by Baumeler, 2017.

In 2005, the demand of 21 Mm3/year was met by: 1 Mm3 from boreholes, 5 Mm3 from the New Goreangab Water Reclamation Plant (Figure 31), and 15 Mm³ from surface water in reservoirs (van Rensburg, 2006). The reclamation process is based on the multiple treatment barriers concept to reduce associated risks and improve the water quality. This includes pre-ozonation, enhanced coagulation/dissolved air flotation/rapid sand filtration, and subsequent ozonation, biological and granular activated carbon, filtration/adsorption, ultrafiltration, and chlorination (van Rensburg, 2006; du Pisanie, 2007).

Photos of the new Goreangab Water Reclamation Plant

Figure 31  New Goreangab Water Reclamation Plant (van Rensburg, 2006).


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