City starts using emergency water
The City of Windhoek has started supplying the southern suburbs with borehole water from the Windhoek Aquifer, which is the city's emergency supply.
06 August 2018 | Disasters
These savings are critical to maintain since abstraction from the Windhoek Aquifer, the city's emergency reserve, is unsustainable.
Windhoek's southern suburbs will be primarily supplied with water from at least nine boreholes that were drilled in the aquifer over the past year.
This is a first for the City, which has been preparing to launch the aquifer supply scenario for more than a year, in anticipation of a possible drought following the lengthy water supply crisis that ended last year.
Last week the City announced that water savings had to be increased from 5% to 10% after inflow to the central dams supplying Windhoek amounted to 24.91% of the average expected inflow, as announced by NamWater recently.
Residents were applauded for saving as much as 7.69%, more than the required 5% each month.
As of 1 August, at least 20 000 cubic metres of water will be pumped from the boreholes to supply households in Academia, Pionierspark, Kleine Kuppe, Olympia and Auasblick.
This supply strategy was designed to address the lack of inflow to the three main supply dams of NamWater, which has now halved its supply to the City, from around 60 000 cubic metres daily to 30 000.
In addition, Windhoek will receive 17 000 cubic metres a day from the Windhoek reclamation plant, the maximum output that can be provided.
Yet, in order to ensure the new daily usage target of 67 000 cubic metres a day can be achieved, residents have a vital role to play by ensuring 10% water savings.
Koos Theron of the City of Windhoek's infrastructure, water, and technical services division explained that it is crucial residents do their part, pointing out that the current water supply operation is highly risky as it relies on an emergency resource, the aquifer.
He explained that the current abstraction of around 20 000 cubic metres a day from the aquifer is not sustainable over the long run, based on the average natural recharge of the underground water source which amounts to around 1.7 million cubic metres per annum.
At the current rate, around 7.5 million cubic metres per annum are being extracted, almost 4.5 times the recharge rate.
“If everybody can contribute, we should be able to get to the 67 000 cubic metres a day. If we do not, we have to exploit the City of Windhoek boreholes further, which is not a good option, because we are already using our 'retirement money'. Or we could ask NamWater to supply more water, but then we are not sticking to the plan. The easiest way is water demand management,” he said.
Theron explained that all relevant stakeholders have agreed to immediately convene a meeting should there be a substantial inflow into the dams, to discuss whether the current supply scenario can be amended.
He added that the first change would be to reduce the pressure on the aquifer, by either reducing the extraction rate or shutting it off completely.
This may not be on the cards soon as the American National Oceanic and Atmospheric Administration has predicted an increasing chance for the El Nino weather phenomenon during the coming rainy season.
According to the administration, El Nino will strengthen to around 65% during spring and will strengthen further to 70% during the summer season.
El Nino typically reduces rainfall and a strong occurrence almost guarantees lower than average precipitation increasing the chances for drought.
This does not bode well for the economy. By May this year, the construction industry had seen 30% job losses with more than 60% of the industry's businesses closing their doors. Roughly 60 000 jobs had been lost across all sectors during the 2016/17 financial year due to the depressed economic conditions, coupled with low rainfall.