The water in the basin comes from local rainfall, runoff in ephemeral rivers and aquifers (underground water storage). The Cuvelai drainage system originates in Angola and spreads across the flat plains in Namibia, resulting in shallow ephemeral watercourses (called "oshanas“). Major floods (called „efundja“) from local rainfall and floods from Angola contribute to the formation of a wide network of waterways (called the Cuvelai Delta). These waterways drain into the Omadhiya lakes. The Ekuma oshana flows southwards out of this series of lakes and pans (mainly the Oshituntu pan) into the Etosha Pan. Etosha also receives water from the Omuramba Owambo, in the east, which feeds into Fischer’s Pan. However, most of the water supplied by NamWater in the basin is imported from the Calueque Dam in Angola on the Kunene River. Water from Calueque can also be stored in the Olushandja Dam, which is connected to the Etaka Canal and Ogongo-Oshakati Canal. A network of pipelines and water points supply the basin population and livestock with water.
Groundwater is abstracted mainly from the Ohangwena Kalahari Aquifer and the Discontinuous Perched Aquifer (where fresh water is only found in certain parts of the aquifer) by means of boreholes. Shallow wells (known as „omithima“) and deep wells (known as „oondungu“) are used to supply water, especially to isolated villages in the basin. The underground water system in the Tsumeb sub-basin is known as the Karst Aquifers (water bearing structures in dolomite rock formations). There is a large water filled cave, Dragon’s Breath Cave, and sinkholes filled with water (formed when the roof of an underground cave collapsed), namely the lakes at Otjikoto and Guinas.
Several excavation/earth dams are found in the Cuvelai area. The dams are constructed in oshanas and collect seasonal surface water, which is primarily used for livestock water supply. Although the dams are expensive to build, the water is free for people and livestock to use. The major disadvantages of earth dams are that they can only recharge water in one place and that is not good for storing water because they lose most of the water through evaporation. The water in earth dams is usually dirty and is not safe for people to drink, unless it is filtered and boiled.
The institutions responsible for water resources are divided into the following categories for ensuring efficient and effective management there of:
• Overall water resource inventory, monitoring, control, regulation and management: Directorate of Resources Management within the Ministry of Agriculture, Water and Forestry (MAWF).
• Bulkwater supply: Namibia Water Corporation (NamWater) abstracts water from primary sources (e.g. rivers, aquifers or dams) and supplies to some end-users directly.
• Self-providers: Commercial farmers, tour operators, mines and nature conservation (parks), subject to appropriate agreements and licences, supply their own water.
• Water supply to rural areas: Directorate of Water Supply and Sanitation Coordination in the MAWF.
• Water supply to urban areas: Local Authorities and Regional Councils buy water from NamWater or supply water from own boreholes for delivery to end users.
The Constitution of the Republic of Namibia is the primary law for sustainable resource management and equal distribution of water to the people. Specific documents dealing with water management include the: Water and Sanitation Policy of 1993; Namibia Water Corporation (NamWater) Act of 1997; National Water Policy White Paper of 2000; Water Act 54 of 1956 and Regulations, soon to be replaced by the Water Resources Management Act (2004) [which has not yet entered into force and is currently under revision] and the Water Supply and Sanitation Sector Policy of 2008.
The Water Resources Management Act makes provision for the establishment of basin management committees (BMCs) to make sure that integrated management takes place at the basin level. The role of a BMC is to provide scope for addressing various issues affecting water resources in the basin, ranging from efficient water use to monitoring the health of the basin.
The aim of such a committee is to equip basin communities to take full ownership of their own development (through developing a strategic basin management plan) with strong support from the relevant service providers. The committee is ideal for knowledge and experience sharing to realize a common vision for the basin, through IWRM principles such as stakeholder participation, transparency and information sharing. The process of establishing basin management committees is currently being implemented in phases.