1.1.1.WATER RESOURCES The total renewable surface water resources are estimated to be 11.1km3/year, of which the Senegal River and its tributaries constitute the main part (these form the border between Mauritania and Senegal); and the dam reservoirs scattered in the southern and central regions. Of the total (11.1km3/year), only 0.1km3 is generated within the country. The country also contains significant groundwater resources, although these are characterized by large geographical disparities. The context is favourable in the southwest, south and southeast (large continuous sheets of Tarzi and Taoudenni in sedimentary formations, layers of the river valley; high flow-time) and less favourable in the rest of the country (discontinuous layers). Renewable water resources are estimated to be around 0.3km3/year. The total capacity of dams is estimated to be about 0.9km3, of which 0.5km3 are for the Foum Gleita dam. In Mauritania, water resources are mainly surface water. The surface waters are estimated to be 7.1km3, and 54 per cent of them are used (3.75km3). Given the very limited role of undergroundwater resources, this figure can also be taken to represent the overall rate of mobilization. Out of the 3.75km3 mobilized, Mauritania uses only 1.3km3, meaning a rate of use of 17.5 per cent (United Nations Economic Commission For Africa (ECA), 2005a). Mauritania’s comfortable position with regard to water resources is only relative; the country possesses, in the River Senegal, the possibility of extracting sufficient water to meet its needs for a few decades to come, but the geographic situation of this resource makes it difficult for the water to be distributed across the regions (ECA, 2005a). Moreover, most of Mauritania is situated in an arid zone, which means that actions must be taken to manage water demand, but the context is not conducive to such actions: the management structures are fragile and the responsibilities of the bodies in charge of managing water have been diluted (ECA, 2005a). Mauritania is heavily dependent on outside sources (96 per cent): this dependence on outside sources for its water resources is measured in relation to its water potential (ECA, 2005a). According to ECA (2005b), the volume of water generated by precipitation (92mm) is evaluated in Mauritania to 94 Mm3. But taking into account the aridity of the climate, the water flow is very low: the volume of surface water is estimated at only 100 mm3. The Senegal River, which rises outside Mauritania, contributes 7,000 million m3 to the renewable water resources of Mauritania. Apart from the Senegal River, six rivers, draining watersheds of 2,000 to 8,000km2, are identified. The only information mentioned in the national report is that of “the dams feeding groundwater sheets”. The same source, probably to emphasize the performances of these dams, states that the Amder dam stored 160,000 m3 during the winter of 1986, which indicates that, apart from the Senegal River, there is a modest contribution from other rivers. Concerning groundwater, ten sheets are identified; four of which belong to the Senegalo-Mauritanian basin, and six to the basin of Taoudéni. The national report of Mauritania indicates that the groundwater potential of water is estimated at 50,000mm3, specifying however that “this potential is supposed nonrenewable” (ECA, 2005b). According to ECA (2005b), in Mauritania water resources are primarily surface ones. Surface water, evaluated to be 7.1km3 is used to 54 per cent (3.75km3). Taking into account the small contribution of the groundwater (0.3km3), this rate could be considered as the rate of total mobilization. Of the 3.75km3 mobilized Mauritania uses only 1.3km3, a utilisation ratio of 17.5 per cent. No evaluation is made for water resources mobilization in the long-term, but it appears that in 2025 the country will have largely sufficient water resources to meet its needs. Non-renewable water resources According to ECA (2005b), the national report of Mauritania indicates the existence of 10 groundwater sites with a great disparity in water potential according to the geographical situation: the southwest, the south and southeast contain water reserves estimated at 50km3, but this potential is assumed to be “non-renewable”. In 2000, water withdrawals were estimated to be 1.698 billion m3, including 1.5 billion for agriculture (88 per cent), 150 million for domestic use (9 per cent) and 48 million for industry (3 per cent). 

(Water Risk Filter)