Improving water management practices in the Rahad Scheme

This study aims to investigate and develop proper operational water management tools for the Rahad irrigation scheme. The Rahad project is considered as being among one of the schemes that could have a huge potential for expansion in the near future after the heightening of the Roseires Dam. The water supply sources for the Rahad scheme are the Blue Nile River and the Rahad seasonal river. The study explores options of augmenting the supply from the Rahad River during the wet season with the goal of minimizing sedimentation problems on the supply canals, reducing operation and maintenance costs associated with the Mena pumping station. Crop water requirements for the Rahad scheme were computed based on the historical cultivated areas of the different crops for the period 2000-2004. The Water Delivery Performance (WDP) Indicator for the scheme was evaluated. Frequency analysis and flow duration curves for the historical records of the Rahad seasonal stream were conducted in order to establish the yield of the Rahad River at different assurance levels. It is found that the yield from the Rahad seasonal river with 90% assurance level could be adequate to maintain an optimum performance of the irrigation system. Such proposed water management tools would improve the WDP by more than 25%. The dependence on the Rahad River during the wet season to meet the project irrigation water demands is anticipated to significantly minimize the maintenance and operation cost of diverting water from the Blue Nile.