Govt. considers Okavango River and desalination of sea water

29 Jul 2015 12:50pm
WINDHOEK, 29 JUL (NAMPA) – Government is considering and investigating both the Okavango River and the desalination of sea water to determine the most secure and reliable long-term water sources for businesses and residents up to 2050.
It is estimated that water taps in Namibia could run dry by June 2016 if urgent measures are not put in place to solve the problem.
There are currently 14 water supply networks of the national water utility, Namibia Water Corporation (NamWater) which include: Berg Aukas-Grootfontein scheme; Calueque–Oshakati canal; Dreigratsdrift-Skorpion Mine scheme; Grootfontein-Omatako canal; Koichab Pan-Lüderitz scheme; Kuiseb-Mile7 scheme; Naute-Keetmanshoop scheme; Omafo-Eenhana scheme; Omatako-Von Bach scheme; Omdel-Swakopmund scheme; Swakopmund-Langer Heinrich scheme; Swakopmund-Rössing scheme; Swakoppoort-Von Bach scheme; and Von Bach-Windhoek scheme.
At a public meeting last week on long-term water solutions for the central areas of Namibia and the Cuvelai, Chris Brown from the Sustainable Solutions Trust said there are four short- to medium-term solutions or options, if implemented now, which will provide central Namibia with water for about eight years only.
“There are just two long-term solutions or options for the central area, which is the abstraction from the Okavango River and desalinated sea water from the coast,” he noted.
Desalination, also called desalting, is the process of removing dissolved salts from water, thus producing fresh water from seawater or brackish water.
The Ministry of Agriculture, Water and Forestry (MAWF), the Namibia Water Corporation (Namwater) and the City of Windhoek organised the event. Similar meetings already took place in Rundu and Oshakati last week.
The objective of these events were to examine all feasible options for securing long-term water supply to the central area and the Cuvelai area of Namibia, where existing sources might become inadequate in the near future.
Namibia needs about N.dollars 1. 5 billion to provide water to the country’s about 2.3 million inhabitants.
Abstraction from the Okavango River was modelled to be activated only when shortfalls are expected from other sources such as dams, aquifers and reclamation plants.
On commissioning during the year 2023, the river could withdraw about 25 million cubic metres.
The maximum abstraction by 2050 for the Windhoek area would be about 61 million cubic metres, with additional demands from Otjiwarongo, Otjinene, Omaruru contingencies of 21 per cent.
Developmental needs of the north-east of the Otjozondjupa Region and north of the Omaheke Region means that the abstraction from the Okavango River by the year 2050 would be between 82 and 105 million cubic metres. This does not include any other branching lines or impacts of climate change, according to Brown.
About desalination of sea water from the coast, Brown stated that it was not seriously considered before because of the costs involved in pumping water for up to 1 600 meters.
Another constrain is also because Namibia does not have enough energy to pump the water from the coast. The volumes of desalinated water to Windhoek will be about 17 million cubic metres in the year 2023 and about 57 million cubic metres by the year 2050 – less than via the Okavango River because of fewer losses along the transfer system.
“If the international community would be prepared to invest in Namibia but avoid abstraction from the Okavango River, then it could be feasible.
“There are thus a number of important questions and challenges around abstraction from the Okavango River, and if another solution was available, that would be worth serious investigation,” Brown added.