Hydrological Services

The hydrological cycle in Namibia indicates that of the rainfall received, 83% is evaporated, 17% is used up by plants, 14% is lost through transpiration, 2% is run off in the rivers and 1% seeps underground, which may later be extracted through boreholes for consumption. Namibia sources of water are: border rivers, dams on ephemeral rivers, ground water, fountains, seawater desalination and recycled water.

WATER AS A NATURAL RESOURCE

WATER AND THE CONSTITUTION OF THE REPUBLIC OF NAMIBIA

Article 95 (1) of the constitution of the Republic of Namibia makes provision for the “utilisation of living natural resources on a sustainable basis of all Namibians, both present and in future”. Article 100 of the Constitution of the Republic of Namibia says that land, water and natural resources belong to the state.

WATER RESOURCES

Namibia is the driest country south of the Sahara. The country’s annual rainfall figures ranges from 550mm to 600mm in the far North to between 250mm to 300mm in the South. The central part of Namibia, which includes the capital city Windhoek, has the annual rainfall figures of between 450mm to 500mm. The North part of Namibia referred to as Cuvelai extends to the border with Southern Angola and has an annual rainfall of between 250mm to 350mm. The eastern part of the country, which also hosts the Kalahari Desert, receives between 50mm to 250mm of rain. The coastal part of Namibia which is largely a desert stretches from Oranjemund in the South to Kunene in the North-West. It receives less than 50mm of rain.


BOARDER RIVERS

Namibia has 5 perennial rivers and about 20 well defined ephemeral Rivers.

The perennial Rivers are:

  • Orange River in the South
  • Kunene River in the North
  • Kavango River in the far North
  • Zambezi in the far North
  • Kwando (Linyanti/Chobe) River in the far North.

NAMIBIA`S EPHEMERAL RIVERS

The Kunene, Ugab, Omaruru, Swakop, Khan, Kuiseb, Orange, Fish, Nossob and Hoanib rivers flow into the Atlantic Ocean.

The Zambezi and Kwando Rivers flow into the Indian Ocean while Okavango River flows into the Okavango Delta.

Tsauchab River flows into Sossusvlei while Ekuma and Oshigambo rivers flow into the endorheic basin of Etosha Pan.


NAMIBIA`S DAMS

Namibia has 18 dams with Hardab being the largest at the moment with a capacity of 294 mil m3. The Neckartal Dam is nearing completion and will become the largest dam in Namibia with a capacity of 880 mil m3. Many of these dams are constructed on the ephemeral rivers in order to capture and store water for dry periods. Of the 18 dams, 17 are surface dams with the exception of Omdel (Omaruru Delta) which is designed to intercept water and thereafter water is released from the dam and It is only when the water is released form the Omdel that the natural paleo channel is recharged with water.

Central Area Dams

  • Swakoppoort
  • Von Bach
  • Omatako
  • Friedenau
  • Goreangab
  • Kalkfeld
  • Omatjenne

Eastern Area Dams

  • Otjivero Main
  • Otjivero Silt
  • Tilda Viljoen
  • Daan Viljoen

Southern Area Dams

  • Hardap
  • Naute
  • Oanob
  • Dreihuk
  • Bondels
  • Neckartal

Northern Area Dams

  • Olushandja

Western Area Dams

  • Omdel

GROUND WATER

Water is life. In a country as dry as Namibia, water resources are scarce and unreliable. Namibia, the driest country in Africa south of the Sahara, depends largely on groundwater. Surface water availability is closely linked to a rainfall pattern that is extremely inconsistent in both time and space. Excess rain can cause floods that are difficult to manage and during droughts surface water is insufficient, resulting in water restrictions. Groundwater resources, a “hidden treasure” underground, are more reliable, widespread and naturally protected against evaporation. The groundwater stored in the pore spaces between sand grains and in voids of rocks has a regulating function: it can be abstracted during dry periods and filled up again by recharge during good rains.

Over the past century, more than 100 000 boreholes have been drilled and supply groundwater for industrial, municipal and rural water supply. They provide drinking water to man, livestock and game, irrigation water for crop production, industries and mines. The advantage of using groundwater sources in Namibia is that even isolated communities and those economic activities located far from good surface water sources like mining, agriculture and tourism can be supplied from groundwater over nearly 80 % of the country. Despite considerable investment in drilling, borehole design and construction as well as pumping and maintenance, groundwater is usually the most economical way of supplying water.

However, groundwater resources, being closely associated with underground rock types that vary with the geological situation, are unevenly distributed across the country. There are only a few favourable places where high volumes of groundwater can be sustainably abstracted, but fortunately there are also few places where no groundwater is found at all. But even if there is sufficient groundwater in a region, it might be unfit for human use because of its poor quality. The north-western part of the Cuvelai-Etosha Basin and the south-eastern part of the Stampriet Basin, the so called salt block, are prominent examples.

The Namibia Water Corporation Ltd (NamWater) was officially registered as a company on 9 December 1997. It is a commercial entity supplying water in bulk to industries, municipalities and the Directorate of Water Supply and Sanitation coordination in the Ministry of Agriculture, Water and Forestry. The latter supplies water to rural communities.

The Namibian Government is the sole shareholder, represented by the Minister of Agriculture, Water and Forestry who appoints the Board of Directors to ensure the efficient resource utilisation. The company strives to recover the full cost of water supply, NamWater is committed to providing its customers with a reliable source of quality water at cost recovery tariffs.

Of note is that water belongs to the state and that the Minister of Agriculture Water and Forestry is the custodian of Namibia’s water and the National coordinator of water resource management.


SEA DISALINATION

Plans to build desalination plants along the Namibian Central Coast dates back to as early as 1996. Feasibility studies carried out revealed that desalinated water is a viable option to supply the customers of the Central Coast whose demand for potable water has increased to more than the sustainable yield of the ground water resources. However, although NamWater long wanted to build its own desalination plant at the coast, the Water Utility has not yet managed to build a plant of its own citing challenges such as costs and plans are still underway to make this dream a reality.

Currently, Namibia has a desalination plant at the Coast which is wholly−owned by Arano Resources Namibia and operated by Aveng Water Treatment Namibia. This plant currently supplies NamWater with 12 million cubic meters of water a year. This volume of water is sold on to the Mines and Industry in general located outside the town lands. It has the short−term capacity of 20 million cubic meters per Annum, and can be increased over a medium to long−term capacity of up to 45 million cubic meters a year.

The Erongo region’s water demands for the communities and the mines currently stand at about 20 million cubic meters per annum. Consultants have been appointed to commence with a KfW sponsored feasibility study to consider the future supply of water to the Central Coast and the Central Areas of Namibia and even as far as Botswana.


WATER RECYCLING

According to Piet du Pisani, who was the strategic executive for Infrastructure Water Technical Services at the City of Windhoek the realization that water should be re-used is fast gaining momentum.

Following the very successful 9th International Water Association’s (IWA) conference on Water Reuse in Windhoek during 2013, it became apparent that waste water is no longer seen as a waste product, but rather as an important and reusable commodity.

“Windhoek is a living example that even the top mode of reuse, potable reuse, is feasible, practical and safe,” said du Pisani during the Conference. Namibia is a pioneer in potable water reuse with the Goreangab Reclamation Plant that has been providing drinking water to the growing capital for the past 45 years.

To date, Windhoek is still one of the only places in the world where sewage effluent is directly treated into potable water. At the water reuse conference, the then Minister of Agriculture, Water and Forestry, Hon. John Mutorwa said the government intends to make substantial-investments in the long-term in water infrastructure of Namibia. According to the Minister, Namibia has also commissioned a study to conduct an Engineering and Environmental assessment of all options for the augmentation of water supply for Central Areas of Namibia and for the four Northern Regions.


EVAPORATION

Namibia’s annual evaporation ranges from 2 600 mm in the North East to 3 700 mm in the central Southern area. Evaporation is highest during the months of October to December and dams in Namibia can lose between 20% and 85% of their water through evaporation within one season.