Experts discuss desalination details Details of how a desalination plant at the coast will operate and pump water to Windhoek were provided at a recent public discussion held to debate the feasibility of such a facility. The discussion, with the theme ''Is Desalination a Sustainable Solution to Namibia''s Water Crisis?'', was aimed at bringing a range of experts together to debate the feasibility of a desalination plant at the coast and to help decision-makers arrive at a sustainable solution.
According to a summarised report of the discussions, the Areva desalination plant cost N$3.6 billion to construct and it would take about three years to build something similar.
A plant that can produce 25 million cubic metres of water per year would cost about N$2.7 billion, and the size of the plant can be increased as demand increases.
The report explains that desalinated water will be pumped from the coast to the Von Bach Dam and not straight to Windhoek.
A plant of this size would require 20 to 25kW of electricity, and an additional 20-35kW would be needed to pump the water to Windhoek.
It was further explained that during the desalination process, the water extraction point is located about 1 km from the sea at a depth of 10 meters in the ocean.
Water is extracted from the middle of the ocean and no trawling or surface water is used because the middle water is best quality compared to water at other levels. During the desalination process, no salts are touched and the process simply removes 35% of water and everything else is released back to the ocean in higher concentration and at the same temperature.
Meanwhile, Dewald Duvenhage from the Swakopmund municipality stressed that the coastal area is in water dire straits.
He attributes this to increased mining operations in the region that have also resulted in increased water consumption.
According to him, industries in Windhoek are currently suffering because there is no water and therefore these industries will be enticed to move their operations to the coast.
He also said the money generated by having industries at the coast can be used for desalination.
“Since there will be no water without electricity, this problem needs to be resolved first.”
Andre Burger from the Walvis Bay Municipality explained that the coast gets water from the Kuiseb aquifers and the Omdel scheme, of which 2011 was the last recharge period after the rain. Currently these aquifers are not able to supply the water demanded.
The Omdel aquifer levels have been declining over the years, and a new reservoir is being developed at Mile 7, its completion expected next year.
He concluded by saying that the local authority is not yet ready for desalination due to institutional problems. The report also said while the NamWater agreement with Areva is ending in October, the contract is renewable every quarter through a confidentiality agreement and it will definitely be renewed. With the Husab mine coming on board, this means that the water tariff will be reduced. Currently, the water demanded from the desalination plant is significant and the plant is supplying more water than was initially planned. The supply to Husab mine and the other three uranium mines will have a longer term agreement, not just the yearly agreement, as the desalination plant was designed for a 20-year period.
ELLANIE SMIT