Sustainability of Raw Water Supply in Nawuni River for Tamale Metropolis and Environs, Ghana

Abstract

Water supply service is possibly the most essential of all public service in Ghana and any obstruction to its delivery threatens human survival. A major challenge to water supply is the rapid urbanisation, which has increased water demand in the urban areas, placing pressure on service providers to meet demand. Perennial water shortages in Tamale, is linked to several factors including the inability of the service provider to keep pace with the demand of the rapidly increasing population of the city. This situation could be exacerbated by natural climate variation and competing water uses upstream the city supply source. This study investigates the sustainability of raw water supply to Tamale metropolis and environs using Water Evaluation and Planning Model (WEAP). The investigation was based on scenarios analysis: Reference scenario, Population and Socio-economic growth, intensifying upstream water use and Extended Dry Climate. The results revealed that, intensifying upstream water use as projected in the study do not have impact on the downstream water availability for sustainable water supply. However, the assessment based on High Population and Socio-economic growth results showed significant value (229 million cubic meter) of Unmet Demand in year 2035 for Urban and rural demand site. The results also showed that, the water demand will outstrip raw water supply by 2029 when Extended Dry Climate occurred under scenario High population and Socio-economic growth. Possible options of water storage reservoir should be investigated so as to mitigate the effect of extended dry season.

Keywords: Downstream water, Reliability, Supply requirement, Supply delivered, Un-met demand.

DOI: 10.7176/JEES/13-6-05

Publication date:August 31^st 2023