ASSESSMENT OF WATER RESOURCES POTENTIAL IN RUVUBU RIVER BASIN (BURUNDL EQUATORIAL NILE LAKES BASIN)

Abstract

Water not only survives life on: our Planet, but also provides populations comforts and luxuries, owing to its various uses. The natural resources of Burundi have been seriously degraded since the beginning of the socio-political crisis which the country has been experiencing for one decade. The overexploitation of arable lands, overgrazing, tilling of steep slopes and the phenomena of erosion in various forms account for the degradation of natural resources which are the basis of its economy. The undertaken study tries to document the main basin of Nile basin part of Burundi, Ruvubu basin, in terms of water resources potential development for irrigation and hydropower. Therefore, the potential irrigable area and potential hydropower sites have. been assessed for future development and thereby contributing to alleviate the current deteriorating situation. The availability of surface water to balance demand and supply for irrigation development and the theoretical potential power has been estimated for the identified sites. Accordingly, about 51 ,768 ha are identified as developable areas using river runoff irrigation system based on land slope criteria (:5 10%). The total required gross water for developing such areas considering 0.741/sec/ha as field water supply is evaluated at 0.602 km3/ year. Based on natural inflow discharge and the natural river bed altitude (river bed altitude � 15.00m) to supply by gravity the command area, the available surface water for the above issue is about 32.6 m3 /sec which can satisfy about 85% of Using the collected and compiled data of natural inflow discharge (baseflow) and the natural gross head and topography features derived from topographic map, about 80 sites with a totalyotential theoretical power of about 400.MW are identified in different sub-basins of Ruvubu. The adopted procedures and obtained results show that there is sufficient flow for implanting surface irrigation system in the basin. However, for sustainable water resources development for both irrigation and hydropower and others multi-purpose usage, it needs the implementation of water storage system which is not practiced nowadays. With this regard, based on unique criteria of topography feature of the area, about 20 sites are assessed potentially suitable for reservoir building for one or both purpose depending upon the location. Furthermore, based on the prevailing conditions, suggestions measures are highlighted at the end of the work how to reverse the current deteriorating situation. However, the adopted procedures and methodologies and the obtained results in this , study are based on limited data and information and therefore involved a systematic study for validation. But, the results of this study can be used at preliminary stage for decision-makers and updated with field investigations and Environmental assessment aspects of basin.