|Water Management in Africa and the Middle East: Challenges (IDRC, 1996)|
|Part II - Subregional contributions|
Lecturer, Faculty of Science and Technics, University of Abidjan, Abidjan, CdIvoire
The main sources of water in West Africa are rain, surface water, and groundwater. In recent times, changes in climate, deforestation, and drought have seriously affected these resources in most parts of the subregion.
Rainfall diminishes progressively from south to north and as altitude increases. Some regions receive plenty of rainfall, and others get very little. Generally, however, much of the region receives sufficient rain, but the full potential of the rainy seasons has not been exploited. During certain months of the year, water is plentiful and sufficient to cover the dry spells that follow, but techniques to harvest this water are lacking.
The equatorial forests get plenty of rain, but their soils are poor. The peasants who live in the forests cannot afford fertilizers, so they keep clearing one patch of land after the other. This constant relocation makes the construction of waterworks impractical.
There is inadequate rainfall in tropical areas, so people rely on permanent rivers or wells. In tropical dry areas, rains are insufficient during the major part of the year, although the soils are rich. People use water from wells and boreholes to irrigate their farms.
The arid areas receive hardly any rainfall. They are occupied by nomads (with their herds), who live around grazing lands and oases.
In West Africa, especially the humid zone, water is obtained from springs, marshes, lagoons, lakes, and national and international rivers.
Springs and streams
The humid zone has many natural springs and small streams. Springs are found mainly close to the shore and around mountains, such as in the Fouta Djalon in the Man region of CdIvoire. Some of these perennial sources are believed to have thermo-mineral qualities. Natural springs and streams, especially in Precambrian rocks, generally have excellent-quality water and have been used to supply potable water from time immemorial. Unfortunately, these springs are no longer used.
In 1964, most villagers around the Dans Hills in CdIvoire were relocated by the government. New villages were created after 1973, but the people dug wells, neglecting the springs.
Rational use of springs, especially in the mountainous areas and along the shores of West Africa, could play an important role in the supply of potable water to the regions growing population.
In the sub-Sahelian zones, natural springs are scarce, and most of the watercourses have seasonal flow. There is an acute shortage of water, so villagers fetch water from marshes. Even where there are wells, water from marshes is used for household activities (washing, building, etc.), to conserve the wells limited capacity. In some cases, marsh water is also used for drinking, either because the water from the wells is insufficient or because people do not like it for some reason (unusual taste, or location in a sacred forest or near a cemetery). Because water from the marshes is of poor quality, waterborne illnesses, such as diarrhea, dysentery, and cholera, are common. Endemic goitre has for a long time affected people who live around Danannd Biankouma (western region).
CdIvoire is well endowed with lagoons, which include Aquien, Aby, EbriTendo, Potou, and Egny. Local people are proud of these lagoons, and Abidjan is commonly known as the Pearl of Lagoons. The lagoons have various uses: sailing, boaters dances, pirogue (canoe) races, swimming, fishing, and international trade and transportation. The lagoons also play a role in religious life: parts of a lagoon may be worshipped, and sacrifices may be offered to the water spirits on the eve of a fishing trip.
Unfortunately, the lagoons are easily polluted. High rainfall (Abidjan gets 2800 mm/year) washes away the soil, carrying it into the lagoons. However, pollution is mainly caused by human activities: most of the citys domestic and industrial wastes end up in the lagoons. The problem is aggravated by the pressure and waterproofing effects on a sandy soil from the weight of buildings, which forces water down from the surface, either vertically toward the deeper sheets or laterally toward the lagoons.
Freshwater sources are further threatened by the opening of the lagoons to the sea. Before the construction of the Vridi canal, lagoon water was fresh, but today the lagoons receive 10 000 m³ of seawater annually, which nearly equals the 12 000 m³ of freshwater they receive from continental rivers every year.
The two main lakes in the subregion are Lake Chad, along the borders of Niger, Nigeria, Cameroon, and Chad, and Lake Nyos, which lies within Cameroon and Nigeria. Conflicts often occur among the countries sharing Lake Chad, when, for example, the level of the lake declines and small islands emerge, which are quickly invaded by fisherfolk from each country. More than 50 agreements have been signed by Cameroon, Nigeria, and the Central African Republic to regulate the exploitation of the Lake Chad basin.
In the humid zones of West Africa, national rivers are the main sources of water supply for urban centres. Major construction, such as dams, affect not only the ecosystem of the watercourse but also local people, who derive no benefit from either the electricity or fishing. They are often relocated and end up losing their livelihoods. For instance, the Baoul from the central part of the country, were relocated to the southwestern forests in San-Po, among the Krou ethnic group. This has posed some serious problems because the mixing of various ethnic groups has often led to fights over land, sometimes culminating in deaths.
Rivers are often polluted, which is a particularly serious problem where they are the sources of potable water. For example, in the main cities of Cameroon, Yaounde, and Douala, the government has to use expensive chemicals to treat water for urban residents.
The five international rivers in West Africa are the Senegal River, which originates in Fouta Djalon in Guinea, crosses Mali, and enters Senegal after crossing several kilometres along its boundary with Mauritania. The Niger River also originates in Fouta Djalon; it flows through Guinea, Burkina Faso, and Nigeria, before it empties into the sea. The Bua tributary of the Niger River, originates in northern Cameroon, before joining the main course in Nigeria. It links Guinea, Mali, CdIvoire, Niger, Burkina Faso, Nigeria, and Cameroon. The Volta originates in Burkina Faso and empties into the sea in Ghana. Its main three tributaries are Black Volta, White Volta, and Oti. The Logone River originates in Cameroon and the Central African Republic and empties into Lake Chad, and the Chari flows from the Central African Republic to Lake Chad. These two watercourses link Cameroon, the Central African Republic, and Chad.
Conflicts can arise among riparian states over use of international rivers. Congo and Zaire often meet to talk about their common river, which has two names: Congo on one side of the border and Zaire on the other side. There are conventions regarding its use, although each country is keen to keep its name on its portion of the river.
Groundwater is found in loose soils near the shores, in alterites on crystalline bedrock, and in fissures in bedrock in the humid zones of West Africa.
In the sedimentary basins of the shores of CdIvoire, Togo, Nigeria, Guinea, Cameroon, and Sierra Leone, large volumes of underground water are found in the aquiferous strata of Quaternary sediments at a depth of less than 10 m or in older rocks at depths of 10-80 m. Additional resources are found in the Upper Cretaceous sediments, but only at 100-200 m depth.
In CdIvoire, phreatic sheets with discharges of 2-22 m³/h are found in certain Quaternary sands, within the top 10 m. In Abidjan, water is drawn from these sheets at a depth of 3-4 m, from pits dug in the sand, and is used for washing hands and cars, raising pigs and poultry, making bricks, and watering gardens and flowers.
Water sheets of Miocene-Pliocene age are found at the continental edge in clayey river sands near the surface and in coarse sands at greater depths. Flow rates are 7-338 m³/h, but depths may reach 200 m. Abidjan is better located for potable-water supply than other cities of West Africa. Although all the phreatic waters of the continental edge risk pollution from seawater, in Abidjan the beds feeding the city are sheltered from seawater incursions by the lagoon fault.
Beds of alterites on crystalline bedrock
Peasants and drillers are familiar with groundwater occurring in beds of alterites lying on top of crystalline bedrock. For a long time, they were considered the only sources of exploitable water resources on bedrock. These alteritic reservoirs reach 50 m thick in CdIvoire (100 m in the cocoa loop above volcanic sediments) and 10-20 m thick in the humid zones of West Africa. Deeper layers are composed of grainy grits and are the most productive and sought after. However, these zones are generally not more than 5 m thick. Exploitation of alteritic reservoirs is decreasing because of the depth at which the water is located and the thinness of saturated zones. Large-diameter water wells, even those of modern design, cannot normally reach beyond 30 m.
Alterite water reservoirs are subject to significant seasonal variation (decrease of the sheets in the dry season and refilling in the rainy season) and can easily be depleted because of the limited height of the water column. Local use by people with ropes and buckets can reduce its level. In alteritic beds in the north of CdIvoire, for example, 85% of the wells are characterized by a decrease of water level; only 4% show no decrease; and the remaining 11% show a slight increase.
The water of the alterites is used in the rural areas and some urban settlements that are not connected to the mains. Because irrigation is not well developed in West Africa, no real conflict has arisen over water coming from alterite sheets. The real problems stem from pollution and depletion.
Fissures in crystalline bedrock
Water in fissures of crystalline bedrock is generally of good quality and is used for human consumption. Some water is found in schists that have been folded and deformed, which can increase porosity. However, the greatest water potential occurs where the rocks are fractured. Original permeability is generally low, except in detritic layers, which play the roles of drains and locally develop important capacity, but at depth.
Migmatic reservoirs are aquiferous, which can be seen by the impressive number of water traces recorded in the bedrock. In fact, at depths of 120 m in Mali, 124 m in CdIvoire, and 400 m in the Tarkwa mines in Ghana, numerous traces of water were recorded, revealing the high water content of the undisturbed crystalline formations. Water circulates in those crystalline rocks through networks of fractures that serve as drains and that are capable of discharging sufficient quantities of water when reached by drilling.
As reservoirs, fissures appear to be more regular and more stable than the alterites. Fluctuations of water levels do not generally exceed 5 m one way or the other, which indicates rapid replenishment. Even after significant withdrawals, the wells readjust their water level as soon as there is a break in the pumping.
Exploitation of groundwater
There are various methods of exploiting groundwater. Sumps or ponds provide small quantities of water to some villages in the sub-Sahelian zone. These sumps are small holes up to about 2 m deep, dug into the alluvial soils near beds of small lakes or rivers. They often last for a very short time, from a few days to a week or a month, but never from one season to another. During the rainy season these sumps often overflow. Although large volumes of water can be drawn easily into these pits, the water is of very poor quality.
Peasant wells are typically 3-10 m deep and 1 m in diameter. Women draw water from the wells by hand. The wells are dug into surficial alterites on plateaus and hills close to villages. Rains easily feed these wells, but during the dry season, water levels decrease, and in some cases the wells dry up. These wells are dug by hand by Malian or Burkinabsinkers, seldom by Ivoirians. The wells are tubeless, and the concrete coping, built 0.5-1 m above the soil surface, is the only means of protecting them from pollution.
Modern wells generally penetrate the whole thickness of the disturbed geological layer above the sound bedrock. However, the depth of the wells is limited to the sandy or clayey alterites and to the maximum capability of the drilling equipment (35 m). These water points are built with a diameter of 1-2 m (cistern wells), which allows them to store considerable amounts of water. This water is easily drawn by groups of women, each holding a rope attached to a pail. Maintenance costs are low, and breakdowns are rare. However, because of their limited depth (8-35 m), they are subject to the same seasonal effects as the peasant wells and generally do not reach the most productive levels (coarse-grained sands) at the top of the bedrock. Furthermore, the risk of pollution is high because of the possibility of seepage.
The diameter of deep wells is small, not more than 20-23 cm through alterites and 15-16 cm in bedrock. However, their depth reaches 124 m in CdIvoire (drilling of Brou Akpaoussou in Bondoukou). The protection of the wells is easy because they essentially gather water stored in the fractures of the crystalline bedrock. In CdIvoire, several types of pumping equipment are used, of which the most modern can exploit water located at depths of 80 m or more and discharge about 1 m³/h.
Unfortunately, these pumps can be difficult to handle and often break down. Field surveys from 1984 to 1987 showed that of 212 wells constructed since 1982, nearly 23% were out of order at any given time. More than 8% of these wells were rejected by the population because the water had an unusual taste, or the wells were on sacred land or too far. Some 18% were dry. Estimates in 1986 indicated that 15-20% of the pumps were experiencing technical problems or breakdowns. An earlier investigation by the World Health Organization, in 1976, showed that breakdowns increased after three years of pump operations and that 40-80% of the pumps originally installed may no longer be working.
Water institutions and pricing
A number of African countries have come together to create the Union africaine des distributeurs deau (UADE, African Union of Water Distributors). Member countries are Benin, Cameroon, CdIvoire, the Central African Republic, Congo, Djibouti, Gabon, Ghana, Guinea, Burkina Faso, Liberia, Morocco, Mauritania, Mali, Niger, Rwanda, Senegal, Sudan, Tunisia, Chad, Togo, and Zaire. Thanks to UADE, certain principles for improved water exploitation, distribution, and pricing are practiced by the member states. Perhaps it is even more important that West African states have created a water research organization, Comitntert dde hydraulique, which has, among other things, improved the state of knowledge concerning fissured rocks bearing water.
Organization in CdIvoire
According to estimates, in 1964 more than 70% of the villages in CdIvoire lacked sufficient or good-quality water. Water-related diseases were endemic. From 1973, because of disparities in water distribution and a severe drought, the government launched a big water program: Program national de lhydraulique. This program was supported by a national water fund, Fonds national de lhydraulique, inside the Caisse autonome damortissement, and by an autonomous water service department in the ministry.
From 1973 to 1988, the plan aimed to
· supply potable water to all urban centres with more than 4000 inhabitants; and
· equip villages with more than 100 people with water points, with supplementary points for each additional 600 inhabitants.
The program was highly successful. More than 270 communities were provided with potable-water systems, and more than 12000 water works were built in almost 8000 villages. By 1985, more than 80% of the population was supplied with potable water in both urban and rural areas.
Up to 1988, the national water program had invested 104 billion XAF (in 1996, 277 CFA Francs [XAF] = 1 United States dollar [USD]) for urban activities alone, plus another 40 billion XAF for water works in rural villages. Of this 144 billion XAF, nearly 9 billion was from the government and the rest was from international development agencies. In 1988, the program was revised, with the following objectives:
· provide water in 168 small urban and rural centres with more than 4000 inhabitants;
· maintain the level of water supply, through programs to strengthen production utilities and extend distribution networks;
· restore existing waterworks in villages where they were exhausted, defective, or insufficient;
· increase the number of water points to meet identified needs, with a total of 15000 to be installed by 1990; and
· create awareness and train villagers to undertake the maintenance of the pumps.
In CdIvoire, water is treated as a commodity and sold at a price that reflects cost. Of course, in the sub-Sahelian areas, where water is scarce, cost of supply exceeds by far that in forest areas and especially that in Abidjan. Water in the city is subsidized, although it should be sold at a higher price than in those parts of the country that are close to sources, where piping is not needed.
The aim of water tariffs is to meet the costs of production, including equipment, installation, distribution, and maintenance. The full price is made up of three components: maximum basic price, surcharge, and development charges.
The maximum basic price corresponds to the different charges that are included in the production of 1 m³ of water and a 5% profit margin for Soci de distribution de leau en CdIvoire (SODECI, Society for the distribution of water in CdIvoire), a private company that manages water distribution.
The installations used by SODECI belong to the government. The government borrowed money for these water projects, and the surcharge added to the maximum basic price paid by the consumer is devoted to the loan repayment. The surcharges are kept in a special fund, which, until 1992, was managed by SODECI on behalf of the state. From 1992, the management of the fund was entrusted to the Caisse autonome damortissement.
The development charges cover recurrent costs: extension of pipelines, rehabilitation of equipment, modernization, and reinforcement of lines and other works.
The price depends on consumption, which, among other things, reduces the impact of water pricing on the incomes of small consumers. The four brackets include social (small-scale consumers), domestic (below-scale average consumers),mal (average-scale consumers), and industrial (big-scale consumers). In addition, there is a special rate for administrative use of water, which is payable as a lump sum. For consumers who pump directly, the price is currently set at 193/m³, of which 188 XAF goes to the state and 5 XAF goes to SODECI.
Water is sold at prices ranging from 159 to 350 XAF m³. The prices for this are about 200 XAF in Chad, 168 XAF in Congo, 120 XAF in Burkina Faso, and about 680-900 XAF in Guinea. In Cameroon, water is free up to a certain volume, and tariffs are applied only beyond this point.
A special problem of pricing occurs in rural villages where a well has been drilled but there is no pump. In such cases, there is no direct cost to provide water, but the cost of the pump must be amortized and payments must be made for well maintenance. The state requests some contribution from the villagers, rate is variously set: 10 XAF/pail of water in some cases; 25 or 30/family each week in other cases; and an annual fee of 1 000 XAF/person or 55 000-60 000 XAF per village for each pump in still others. Despite these charges, the state bears an annual cost of 100 million XAF for unreimbursed expenses, just to repair the pumps, and up to now no attempt to increase villager contributions has been successful.
Coordinated management and protection of water resources
Each country in Africa needs a permanent water code to define the techniques and conditions for water exploitation, distribution, and pricing, as well as the techniques and conditions necessary for collective and individual water use and sanitation. The code must include measures to prevent waste and pollution.
In CdIvoire, only the Abidjan water-map sheet was completed during the 1980s, and this sheet covered only one part of the aquifer. In the interior of the country, no town has a study on underground water. Consequently, in some localities, wells supplying drinking water and sanitary latrines are built at random, without taking into account the direction of the flow and the permeability of the soil. Consequently, contamination occurs.
A water code is necessary to define the African standard for potable water. To date, the continent does not have any specific standards for water. It uses the international ones, which do not take into consideration African particularities. For example, in rural areas, the nitrate content is often excessive in consumption water, without the population being aware of this.
The water code must provide for the creation of national and international commissions on management, protection, and use of all important water reserves. Agreements should be concluded on the water reserves to define the conditions of use by members. Such commissions should make special allowance for the particular interests of vulnerable populations. For example, a commission for the protection of the Ebriagoon, of Abidjan, could compel the counties to treat their wastes before pouring them into the lagoon, which would greatly improve conditions for the low-income people living on its shores.
Improvement of water institutions
In West Africa, each state has a company dealing with the exploitation and distribution of water: SODECI in CdIvoire, SNEC in Cameroon, SONEES in Senegal, SNE in Niger, etc. These companies formed UADE. For research, there is an Inter-African committee for water research (Comitnterafricaine ddes hydrauliques), based in Ouagadougou. This committee deals with extension work to spread new technologies and information concerning water in Africa. As well, in the Sahel, an interstate committee for drought control (Comitntert de lutte contre la seresse au Sahel) has been established. This committee is also based in Ouagadougou.
Results obtained by these organizations are already encouraging, but much remains to be done. In certain cases, the quality of service is below standard because of the heavy-handedness of the state in the management and control of water services. Maintenance is badly performed. Much water is wasted through leaks in the pipes, and leaks may last for months. Some people do not pay their water bills, and the loss must be made up by the small consumers, who are helpless and have no procedure for complaints.
It would be judicious to liberalize the field of water and let private societies play a greater role in exploiting water and distributing it in urban areas. This would create some competition and would lead inevitably to an improvement in the quality of service.
Water conservation policy
The water sector needs to be organized in most states of West Africa because there are many large losses of water and other forms of wastage, particularly in public services. However, consumers are unorganized.
Proposals for research
Study is needed of the populations displaced by the construction of big dams. Follow-up is necessary to determine whether these people could return to their original lands or be compensated.
Certain groups remain linked by tradition and by preference to their marshes, even where well water is clearly potable. It would be appropriate to study these people to see whether they could become interested in alternatives to marsh water without modifying their ancestral diet and other practices.
Institutional and economic research
Creation of databases
Attempts are being made in Africa to create a database to include both climatic parameters and surface waters. However, little has been done to gather information on groundwater, not even in those villages where wells have already been drilled and water prospecting is carried out. The necessary studies include the preparation of hydrogeological maps.
Management of pumps
Study is needed to develop regulations for village water systems to check the use of pumps that easily break down or are difficult to operate. For example, the SEEE pump widely used in CdIvoire needs at least two strong women on each handle to operate it. In other cases, pumps are very difficult to repair or require imported parts.
New options are needed for village waterworks to replace the present pumping system with a solar system or an electrical system using submersible pumps. In this case, distribution points may be established in the villages and maintained by selected people. The water could then be sold by the pail or other conventional container.
Reduction of waste
Management of water resources and improvement in distribution networks have to be studied to control waste. Leaks in the distribution facilities must be located and repaired.
Climate change in the Fouta Djalon
One of the most urgent research tasks in CdIvoire is to find ways to manage and reduce environmental vulnerability in the extension of the Fouta Djalon in the western part of the country. Even in their severely disturbed state, the forests of Man are the only source of wood for heating, construction, carpentry, and handicraft (tool handles, kitchen utensils, basketwork).
Coordinated management of the water-vegetation-habitat linkages is needed in the humid zones of West Africa. Lack of surface-water resources is more and more becoming a problem in certain regions, such as western CdIvoire, where vegetation is disturbed by the destruction of forests.
The region of Man-Dananas serious problems of demographic instability (refugees from Liberia), problems in agriculture (erosion of slopes and lack of land), difficulties with transportation (unevenness of soil surface), and climatic problems (degradation of forests). Research in this region would be important for the knowledge of water constraints resulting from the operation of natural systems.
Aquifer rehabilitation and management
Research is needed on ways to reclaim and rehabilitate aquifers and on ways to manage water and treat runoff and wastewater to protect the underlying aquifers. Such projects must take into account the problems of waste management, agriculture, and the potential for seawater incursion.
Lagoons, especially Ebriin Abidjan, should be studied to develop a comprehensive protection plan, including the installation of treatment plants at the head of every sewer.
Rains are very abundant in the humid zone of West Africa, but rainwater is not used except in the natural runoff across the countryside and the recharging of aquifers. Stored rainwater could serve many purposes, which would leave the wells to supply potable water.
In West Africa, water is abundant in the rainy season and scarce in the dry season. Simple designs and construction techniques for underground cisterns are required, particularly for villages located in the Sahelian and sub-Sahelian regions. Basins or excavations could store enough water in the rainy season to meet the continuing needs of the dry season.
Hydrological study is needed for all programs of village water development in crystalline rocks. The goal should be to create a map, or feasibility study, for each village. This would involve the analysis of aerial photography, remote sensing, and geophysics (electric probing and electric tracking). Hydrogeological studies are also needed in urban areas; fortunately, some are under way.
Effects of climate change
In many regions of Africa, there is consensus that climate has been changing for about 30 years: rains are becoming scarce; deforestation is common; and drought is more frequent. Study is needed to determine the extent of the apparent climate change and of its consequences for the water resources in Africa. In particular, we must study the vulnerability of water resources.