Urbanisation and quality of raw water: a case of Weija reservoir

Abstract

The increase in population within the Densu River Basin (DRB) from 450,000 in 1984 to 947,000 in 2000 shows an average yearly growth rate of 3.26%. This therefore has resulted in the increase of anthropogenic activities which have caused contamination with regard to the quality of water of the Weija reservoir. Using a descriptive study design, this study aimed at establishing relationships that existed between urbanization within the DRB and the quality of raw water from the Weija Reservoir for a 14-year period (2002-2016). The study used sixteen (16) water quality parameters, as well as some urbanization parameters such as population and land Use/Cover changes and finally, views of respondents from some sampled communities. The study revealed that water from the Weija Lake has been less influenced by urbanization in the DRB, putting into consideration water quality parameters such as phosphorus, nitrate, ammonia, magnesium, calcium, total hardness, fluoride, iron and sulphate. It was also realised from the study, that the quality of water in connection with parameters such as turbidity, colour, pH, temperature, suspended solids and total solid had been influenced extensively by urbanization for the 14-year period. In view of this, it is recommended that Stakeholders of DRB such as the Densu River Authority (DRA), the Ghana Water Commission (GWC), the Weija Head Works (WHW) and the District Assemblies should ensure that sustainability of quality of water from the Weija reservoir is achieved through clean integration of social, environmental and economic developments as emphasized in the definition given by the Bruntland commission.