Hydrological modeling of artificial recharge of groundwater for sustainable water supply in Dodoma city

Abstract

The growing human population in Dodoma City has resulted in high demand for water use, which has led to the overexploitation of groundwater in Makutupora aquifer. Therefore, this study was carried out to model artificial recharge to replenish groundwater in the Makutupora aquifer to ensure water supply sustainability in the City. The simulation was done in Modular finite-difference flow model (MODFLOW) with the support of ModelMuse and the calibration was done using 21 piezometers. The Geographical Information System (GIS) technique used in preparing the shapefiles and calculation of groundwater storage capacity. The results indicated that the total groundwater storage in the Makutupora aquifer was about 247.84 Million Cubic Meters (MCM). After simulation of the steady-state reference period, the other four stress periods were simulated, considering the projected population and water demand. The planned injection wells to the model in the first, second, third, and fourth transient state periods resulted in a safe yield of 168 857 m3 /day, 197 760 m3 /day, 360 000 m3 /day, and 600 430 m3 /day, respectively. The recommended artificial recharge source is water from the Kinyasungwe river that flows during rainfall time, generally from November to May. One of the recorded years (2007) indicated a flow of up to 23.646 Million Cubic Meters (MCM). The recommended artificial recharge is possible due to the aquifer storage capacity of 247.84 (MCM). Therefore, information from this study could be used by engineers when constructing artificial engineering structures to replenish the water pumped from the Makutupora aquifer.