The water in the basin flows from perennial surface water, ephemeral surface water and groundwater sources. Groundwater/ borehole schemes, operated by Namibia Water Corporation (NamWater) and the Directorate of Water Supply and Sanitation Coordination in the Ministry of Agriculture, Water and Forestry, form the major water source for many of the villages, settlement areas and farms.
Urban centres and irrigation schemes are dependent on three major surface water dams. The dams include the Hardap Dam supplying potable water to the Municipality of Mariental, while surface water is piped from the Naute Dam to the Municipality of Keetmanshoop and from the Dreihuk Dam to the Municipality of Karasburg. Several excavation/earth dams are found in the basin which collect seasonal surface water and are primarily used for livestock water supply. NamWater supplies perennial water from the Orange River to Noordoewer, the Skorpion and Rosh Pinah mines and settlement areas. Namdeb supplies groundwater from the Orange River to Oranjemund.
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: These are commercial farmers, tour operators, mines and nature conservation (parks), subject to appropriate agreements and licences, supply their own water.
• Water supply to urban areas: Local Authorities and Regional Councils buy water from NamWater or supply their own water from boreholes for delivery to end users.
Water is used for domestic purpose (including livestock water for both subsistence and commercial farming) and water for economic activities such as mining, industries and irrigation.
Hardap Irrigation Scheme has 2200 ha under irrigation and is one of the biggest water users in the Basin, taking 46 million cubic meter/year from the Hardap Dam. The major crops grown at the scheme are wheat, maize and lucerne.
Other water related activities in the basin include:
• The 1100 ha Aussenkehr irrigation scheme to produce table grapes.
• The Noordoewer/Vioolsdrif irrigation scheme mainly to produce vegetables and fruits.
• The mines (Namdeb, Skorpion and Rosh Pinah) supplemented by seawater in Oranjemund.
• The Ai-Ais National Park (including the Fish River Canyon) has access to surface water or is provided with water from groundwater sources, mainly to sustain the wildlife and tourist establishments.
• Domestic and commercial livestock and game watering in the main towns, commercial farms and communal areas.
• Limited fish farming, mainly with indigenous fish species, is taking place at Hardap Dam.
• The Orange River mouth supports a vast number of bird and wildlife species and is recognised as a Ramsar site according to the Ramsar Convention on Wetlands of International Importance.
Water demand management - how to use water more efficiently. Water demand management (WDM) is a very important part of IWRM. WDM aims to improve efficiency by reducing water losses or changing the wasteful way people use water. WDM is an approach to achieve „water use efficiency“. WDM is implemented through education and information; training; using economic and financial principles; water pricing and tariff policies (e.g. rising block tariffs) and technical measures. In OFRB, efficient application of irrigation systems (for example drip and micro irrigation) is very important. By doing so, water consumption could be reduced between 15-25% of the total water requirement. In addition to increasing their yield, farmers can reduce water consumption as well as fertilizer costs resulting in minimizing disadvantages to the environment due to high return flows and nutrient levels.
The price of water is determined by the cost of developing a water source; the distance the water has to be transported by pipeline to the consumer; and the topography which determines the pumping head or cost to supply water. The consumer base and technology, i.e. household taps or pre-paid meters, that are affordable to various income groups, also have an effect on the cost of water.
The ability of Local Authorities to enforce credit control measures also influences water consumption. Typical examples in the Basin are Gibeon and Kalkrand, where the water consumption was reduced significantly as a result of pricing structures and the implementation of proper credit control measures. There is proof in most supply centres in the Basin that water demand decreased during the past three years as a result of water tariff increases.
Municipal costs to provide a household with water and sanitation services include charges for water collection from a source; water production (treatment of raw water to drinking water standards); water delivery to the consumer; and wastewater treatment and disposal. Wastewater collection and treatment contribute to hygienic environments and form part of the water chain to prevent pollution to ensure that good water quality and sanitation is achieved. Therefore it is essential that water consumers PAY for water services to ensure continued quality and efficient service delivery.
In rural areas, the community based water management programme under the Directorate of Water Supply and Sanitation Coordination, established mechanisms for users to pay for water services. In addition, mechanisms for transparent and targeted subsidies for those who are unable to pay for water services are being considered. Local water point committees manage local aspects of water services, preventing inappropriate actions such as illegal connections and vandalism to pipelines.
Different ways to save water in urban households:
1. Schedule garden watering for early or late in the day (before 10 am and after 4 pm)
2. Avoid the use of hosepipes for cleaning pavements, floors or cars; instead use buckets
3. Make use of retrofits (replacement with equipment specifically designed to reduce water use) such as:
3.1 Low flush and dual flush cisterns that are being used more and more.
3.2 Reducing the volume of existing toilet cisterns can be achieved by:
*Placing a 1 to 2 litre plastic bottle filled with water, or a brick wrapped in plastic, inside the cistern. This will decrease the volume of water held within it.
*Bending the swimmer arm inside the cistern downwards so that the inflow valve is shut off when the water reaches a lower level than previously.
4. Fix or report to the municipality any moisture or leak problems immediately. Most water leaks occur from toilet cisterns. A single leaking toilet cistern can lose up to 7 000 litres of water per day.
5. Explore rain water harvesting (collection and storage of rain from run-off areas such as roofs) options. Remember - the first flush of new rain should be discarded before collection starts.
6. Keep track of water usage by regularly reading the water meters.
Most of the groundwater within the Orange-Fish River Basin is considered suitable for drinking, although certain areas are prone to high fluoride concentrations that can lead to severe dental and skeletal problems. High nitrate values make the water unsuitable for babies under the age of one year. Increased nitrate concentrations are almost always a result of contamination from human and livestock activities close to boreholes. This type of pollution cannot be reversed, but new abstraction points can be protected by siting habitation, sewerage systems and livestock pens appropriately.
The quality guidelines for drinking water have been set out by the Department of Water Affairs and Forestry, Water Environment Division. Groundwater monitoring is considered very important, not only to understand and identify water quality trends and related indicators, but also to determine the availability of acceptable quality water sources. The Geohydrology division in the MAWF is responsible for groundwater investigation and monitoring.
Sanitation is vital for human health, generates economic benefits, contributes to dignity and social development, and protects the environment. Sanitation promotion focuses on stimulating demand for ownership and use of a physical good. Access to basic sanitation refers to access to facilities that hygienically separate human excreta from human, animal, and insect contact. Hygiene promotion focuses on changing personal behavior related to safe management of excreta, such as washing hands and disposing safely of household wastewater. Both are essential to maximize health benefits. Lack of sanitation facilities and poor hygiene cause water-borne diseases such as diarrhea, cholera, typhoid and several parasitic infections. Provision has been made for both urban and sanitation management objectives and principles in the Water and Sanitation Sector Policy of 2008, to contribute towards improved health and quality of life.
Considering that Namibia is a water-scarce country, in most (rural and urban) instances, the most affordable individual household or community sanitation options are ecological or dry sanitation facilities, however where possible it should be left to individuals to decide on the most appropriate technological and payment options as well as maintenance responsibility allocations.
The institutions responsible for water sanitation and hygiene are divided into the following categories:
• Public health issues and awareness: Ministry of Health and Social Services; Directorate of Water Supply and Sanitation Coordination within the MAWF; Regional Councils and Local Authorities
• Health policies and legislation: Ministry of Health and Social Services
• Advice and research on alternative sanitation options and development: Habitat Research and Development Centre
The IWRM challenges in the Orange-Fish River basin are linked with climate variability and associated changes. In particular, the basin is highly prone to the following challenges:
• Land degradation and deforestation: The topsoil of land contains valuable nutrients for vegetation to grow. When vegetation cover or trees are destroyed (either through high population growth or overgrazing due to high livestock concentrations in an area) the land becomes vulnerable and results in topsoil being easily blown away by wind; increased run-off (rainwater not infiltrating in the soil) therefore causes loss of agricultural productivity (soil fertility).
• Bush encroachment: Invader bushes consume a great amount of groundwater, with detrimental long-term consequences on the sustainability of groundwater resources and fodder availability.
It is predicted that winter rainfall in the basin will decrease which will have negative effects on the local fauna and flora as well as reduced river flow in the lower reaches of the Orange river. Because of the arid and highly variable climate in Namibia, water resource managers and users have to focus on improving efficiency of water resource use through improvement of water demand management practices.
The proposed Neckartal Dam and Irrigation Scheme could become a major development in the area. The dam site is in the Fish River about 25 km upstream of Seeheim and 40 km west of Keetmanshoop. Should it go ahead, the dam would be the biggest in Namibia with a storage capacity of 846 Mm3 with a planned irrigation scheme of 5,000 ha. This is approximately three times the capacity of Hardap, higher up on the Fish River, and currently the largest dam in Namibia. Crop diversification opportunities are currently being explored in the basin, with olive production topping the list.
Future development of proposed copper mining at Haib in the Karasburg district will be dependent upon bulk water supply from the Orange River. Since the Orange River is shared with South Africa, developmental activities in the basin are negotiated through close collaboration with the Orange-Senqu River Commission (ORASECOM) between Namibia and South Africa.