Contribution of Hydrological Modeling to the Management of Water Level Regulation Structures: The Case of the Bango Reservoir, Senegal

Abstract

In a context marked by climate variability and increasing pressure on the Bango water reservoir, the rational and sustainable management of water resources has become a major concern. Indeed, the Bango Reservoir plays a vital role in supplying water to various users (drinking water supply, agriculture, and industry). Today, this reservoir faces the proliferation of aquatic plants and a progressive decline in water levels. Its inflow, mainly ensured by the Lampsar River through a set of regulation structures, strongly depends on the management mode applied to these structures. Thus, the objective of this research is to contribute to the optimal management of the regulation structures of the Bango Reservoir. The methodological approach is based on the development of a numerical model aimed at understanding the hydraulic behavior of the reservoir. The modeling results show that the overlay of the reservoir land cover layer and the flow velocity contour maps indicates an absence of aquatic vegetation in areas where flow velocity exceeds 0.014 m/s. They also show that operating the Ndiol structure at 80% capacity would provide the reservoir with a volume of 19,208,592 m 3 and a surface area of 11,403,943 m 2 . Therefore, opening four gates (out of five) of the Ndiol structure with a discharge of 19 m 3 /s could be considered in order to increase water availability in the reservoir while limiting the development of aquatic vegetation, up to an area of 139.7 hectares.