Rikus Grobler | Oct 18, 2017 | 0
Windhoek to continue with emergency underground water supply
The Office of the Chief Executive Officer, City of Windhoek said in a statement this week that a test programme on emergency underground water is expected to run until October 2017.
As normal abstraction from the Windhoek aquifer has now gone into “maintenance mode” as described by the Office of the CEO, Windhoek is forced to continue with a “testing” process where certain compartments of the CoW aquifer is tested in order to obtain vital information.
The main aim of the Emergency Water Supply project was to find enough water that could sustain 60% of the demand of the city to keep the city functional due to water concerns caused by drought.
The underground water supply was found in reasonable time, which has necessitated the City of Windhoek to look at alternative water resources to sustain the livelihood of the city and all its inhabitants.
As such water is still being abstracted from certain compartments of the CoW aquifer – albeit at much reduced numbers. “The writing was on the wall and there was no time to embark on conventional planning processes as the emphasis was on avoiding a crisis.” The statement read
The statement said, it was originally anticipated to use the increased production from the Windhoek aquifer in keeping the city alive as a data gathering process in order to gain knowledge on the performance of the aquifer – which is a very important part of the aquifer management process which would provide invaluable information for future planning and use of the aquifer.
Following the recent inflows into dams for the central area of Namibia, the City of Windhoek has also reduced the abstraction of water from the underground resource to the absolute minimum – only to keep installed equipment and systems in place and operational.
Although water production has reduced, reservoirs and the water reticulation network is already saturated with elevated levels of these constituents and it may take some time before the system may be flushed clean. Abstraction from the CoW aquifer has in the past proven that there are some elevated levels of especially iron and manganese in borehole water which tends to discolour the product water and items it may come in contact with.
The national water utility (NamWater) also experienced increased iron and manganese levels in water as a result of recent inflow into the dams. That resulted in a batch of mostly murky water being received from Von Bach in the terminal reservoir in Windhoek.
“The problem was solved and we expect water discolouration to reduce to normal, but these can occur from time to time during the testing period.” The statement read. Some lesser used network systems may be more affected as precipitation of iron and manganese will happen in the system.