Assessment of water resources in Makutupora basin, Dodoma -Tanzania

Abstract

In this study hydraulic aquifer parameters, i.e. transmissivity and toragecoefficient, for Makutupora basin in Dodoma were determined. Assessment of the adequacy of the basin yield in relation to the water demand in Dodoma town was made. To achieve the objectives the following methods were applied: Test pumping was carried out using submersible pumps and the data obtained ere analysed.Constant rate test with recovery methods was applied. Also existing data were analysed to determine the parameters. The classical methods applied in the analysis of the data were Theis, Jacobs and Chows methods.Since each method gives a specific value of transmissivity(T)and storage coefficient (S), a mean value each was established by considering reasonable values.The parameters have been applied to calculate draw downs at higher pumping rates. Assuming that all the boreholes in the basin are operating for 24 h/d, the probable basin yield has been determined.It was found out that the transmissivity value (T) is 1.5 x10/3 m2/d and the storage coefficient (S) is 2.0 x 10- 3.By these values the theoretical basin yield is 62 000 m3/d. Although the productivity of a boreholes a function of several parameters like depth, effective diameter, completion and developmenth method, it is assumed that none of the separameters have been altered since completion of the wells.The results clearly show that Makutupora basin has a high potential of groundwater. The basin can safely meet the water demand(54 000 m3/d)of Dodoma up to the year 2008 based on maximum daily demand.This conclusion should still be confirmed for future palans. The confirmation could be done by computer simulations, which calculate the behaviour and the optimum and safe yields of the aquifer.Bigger test pumping unit should be used to determine the yields of the wells. /Kir10