PHYSICO-CHEMICAL CHARACTERISTICS OF THE BUI DAM AREA OF THE BLACK VOLTA RIVER, GHANA

Abstract

Pre- and post-impoundment studies of physical and chemical parameters of water in the Bui dam area of the Black Volta were carried out from March 2011–December 2012. The physico-chemical parameters monitored fell within the ranges suitable for the sustenance of aquatic life in freshwater bodies with the exception of dissolved oxygen, nitrates, sulphates and phosphates. The physico-chemical characteristics showed wide seasonal variations, while between sampling stations the differences were insignificant (p>0.05). Electrical conductivity, total dissolved solids, colour, dissolved oxygen, nitrates and sulphates differed significantly (p<0.05) in the pre-impoundment (March–May 2011), immediate post-impoundment (June–December 2011) and late post-impoundment (January–December 2012) periods. Hence, reflecting the alterations in the river continuum due to impoundment. Nitrates, sulphates and phosphates were outside recommended ranges suitable for aquatic life. The reasons for these high nutrient levels were not clear in this study and therefore require further research. In the interim however, agricultural activities, especially the use of inorganic fertilizers within the catchment area, should be monitored and controlled by the Bole District Assembly, the Bamboi and Bui Traditional Councils, the Ministry of Fisheries and Aquaculture Development and the Bui Power Authority