Simulation of Flood Propagation from the Niandouba Dam Outlet(Kayanga River,Senegal)to the Waïma Lake Inlet Using HEC RAS for Water Resource Management in the AnambéIrrigated Perimeters

Dams are designed for water storage intended to compensate downstream fluctuations that are stabilizing water supply and hydropower production.Hydraulic modelling tools and schemes allow understanding the hydraulic characteristics of the irrigation systems and mitigating uncertainty inherent to dam removals.The construction of the Niandouba dam at the confluence of the Kayanga and Anambérivers(Senegal)has perturbed the natural flow of the AnambéRiver to feed the Waïma Lake and irrigated perimeters.The flow gauges at the Kayanga and AnambéRivers are no longer operational.In this study,the HEC-RAS(Hydrological Engineering Centre River Analysis System)and the RAS Mapper is used to simulate the flow propagation of the Kayanga-Anambéhydraulic system ranging from the Niandouba dam to the entry of Waïma lake.The HEC-RAS modelling enables the estimating of,among other variables,water levels,depths and flow velocities for the different flow configurations and different cross-sectional zones.This study presents a flood mapping of the Kayanga-Anambéhydro system using the RAS Mapper and HEC-RAS hydraulic modelling tools.The study has exhibited the depths at the inlet of the supply channels where the pumping stations are located.