The central areas of Namibia may soon face the stark reality of a hydrological drought after agriculture minister John Mutorwa was personally informed by NamWater that this is the first time it is in the position where the supply of water from the three-dam system may not last until the next rainy season. Consumers can also ready themselves for poorer quality water.
After a presentation, compiled by NamWater’s chief hydrologist André Mosterd, Mutora was urged to declare a hydrological drought as it is projected that the Von Bach dam will run dry by the end of this year, which leaves the City of Windhoek reliant on its own boreholes, the reclamation plant and a small volume from the Kombat and Berg Aukas mines.
NamWater informed Mutorwa that technical solutions should be investigated and implemented to reduce the consumption of water, and that desalination should be investigated as a viable option for supply to the central areas as soon as possible.
The supply needs to be augmented as soon as possible, otherwise the City of Windhoek may face dire economic consequences, according to NamWater.
A very disturbing fact is that according to data collected the users in the central areas have not saved the required 15 percent that was urged at a workshop in April 2015.
The citizens of Windhoek made significant savings in the last three months in which they saved about 20 percent per month. Many industries have also been able to reduce their consumption, after making huge financial investments. The online users between the Kombat and Berg Aukas mines and Von Bach, and between Von Bach and Swakoppoort dams and from Von Bach to Windhoek, including the airport as well as the towns of Okakarara and Okahandja, will be fully reliant on the water from Kombat and Berg Aukas mines as well as own sources if they have them.
It is also a concern that the quality of water deteriorates as the volume decreases. This places a huge demand on the chemical that must be added to the water to maintain the high standard of water that NamWater customers are used to. “We expect this decline in quality to increase as the volumes decrease further,” NamWater states.
According to NamWater, total annual water demand in the central region is approximately 31,8 million cubic metres, of which 25,6 million cubic metres are in Windhoek.
The City of Windhoek will require about N$100 million to pump water from one of the aquifers in the city.
After September this year, the City of Windhoek and NamWater will only be able to supply about 50 percent of the required water demand from boreholes, the reclamation plant and the canal from the northern region.
The overall consumption of water in the central areas must decrease to 30 percent below the normal consumption and the consumption of households should not exceed 90 litres per person per day if Windhoek residents are to survive, NamWater concluded during its recent annual central area meeting.
NamWater also noted that groundwater in the Windhoek aquifer should be seen as an emergency resource, as once the water is over-abstracted it will take 15 years of normal rainfall to recharge
It was concluded at the meeting that technical water demand and use efficiency solutions should be investigated and implemented to reduce the consumption by all consumers. All viable water supply sources and transfer options to the central areas such as desalination must be investigated and not only the Kavango link.
NamWater also recommended that communication to the public should be done by an organisation that specialises in such campaigns.
The drilling of boreholes is not the solution for the water crisis in Windhoek. It has been calculated that the Windhoek aquifer can only supply the 0,5 million m3 on a sustainable basis. When all the boreholes that the city is planning are operational, it is projected that the city will pump about 8 million m3 from the boreholes.
It will take 15 years of normal rainfall to recharge the aquifer to the present levels. Therefore, the supply from boreholes in Windhoek at current levels should be seen as an emergency measure and not as normal.