Abstract

Yonnana Ezekiel, Abdullahi Liman Tukur, and Aishatu Mohammed Mubi

Water Balance Evaluation is an important inventory activity used for continual assessment of water gains and losses in a hydrological basin or water body for the purpose of sustainable uses. In this paper, attempts have been made to present the Water Budget of Lakes Gwakra and Geriyo in the Upper Benue Valley of Adamawa State, Nigeria. The study aimed at determining the gains and losses of the lakes in 2013, 2014 and 2015 Hydrological Years. The studied lakes were selected on the basis of situation on the left and right banks of the course of River Benue in the study area, as well as on the basis of size and relevance in terms of usage. The Derived Water Balance Model used in the study incorporated Direct Precipitation, Evaporation, Surface Inflow, Abstraction, Surface Outflow and Groundwater flux as Net Residual Flux (NRF). The values of the components were computed using data obtained by standard measurements. The results obtained showed high values of Surface Inflows (4.91mcm to 6.86mcm), moderate values of Direct Precipitation (1.16mcm to 2.53mcm) and low values of change in storage (-0.02mcm to 0.06mcm). The high values of NRF obtained indicated high porosity of the area’s geological structure and poor storage capacity of the lake basins. Engineering works and water conservation strategies are recommended for sustainable water storage by the lakes.