Evaluation of Sunyani water supply augmentation scheme

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The reduction in discharge of the Tano River especially during the dry months of December, January, February and March coupled with the size of the Abesim reservoir (operating at full capacity), surface water supply was realized to be inadequate. Groundwater was chosen as an alternative source of water supply. Thirteen boreholes were drilled to augment surface water supply. Seven of these boreholes are large diameter boreholes and six are emergency ones drilled to augment the surface water supply. All boreholes were tested and analyzed for aquifer characteristics and water quality. Borehole yields in the vicinity of hundred liters per minute or more, a specific capacity higher than 5 I/min/m, a good recovery and transmissivities higher than 1x10-5 m2/sec fall within the range that can be tapped to augment surface water supply. All accessible water point sources in the research area were visited and the abstraction rate noted. The average quantity of groundwater abstracted from the aquifer was estimated. The annual rechargeable volume of the research area was also estimated. It was realized that annual recharge of 5.65 x 108 m3/year far exceeds the water need of 5.79 x 106 m3/year in year 2020. Three boreholes Located at Nsuatre North, Nsuatre South and Airport (Sunyani) could be mechanized to supplement municipal water supply though the total quantity obtain from these do not meet the demand. Ten boreholes have low yields and transmissivities, and could be mechanized to serve the local community. One aquifer located at Airport (Sunyani) will be mined if pumped at the rate used for test pumping but the twelve other boreholes can be pumped at rates used for test pumping. There is high groundwater potential and further exploration for groundwater should be undertaken
A thesis submitted to the College of Engineering, Kwame Nkrumah University of Science and Technology in partial fulfilment of the requirements for the award of Master of Science degree, 2002