Physico-chemical Assessment and Environmental Quality of the Waters of Lake Buyo During the Low-water Period of the River Sassandra (South-west Côte d’Ivoire)

In Côte d'Ivoire, almost a dozen hydroelectric dams have been built since 1965, with the opening of the Ayamé 1 dam. These dams, in addition to their primary vocation of generating electricity, also serve other functions such as recreation, tourism, flood control and supplying drinking water to local populations. Lake Buyo is a natural resource of considerable interest for the economic development of Côte d'Ivoire. The Buyo dam, built on the Sassandra River in 1980, is no exception. The aim of this study was to assess the water quality of Lake Buyo during low-water periods of the Sassandra River. To do this, water samples and measurements were taken in the lake in March 2021. In situ measurements showed that the waters were warm, with an average temperature of 32.4°C. The waters were alkaline, with fairly low electrical conductivity. These waters were relatively well oxygenated at the surface and deoxygenated at depth during the dry season. On the other hand, the average concentration of suspended solids (SS) was 4.8 mg/L, and the transparency of 1.48 m showed that the the lake’s waters were not very loaded. Based on the nitrate (1.56 mg/L) and ammonium (0.13 mg/L) concentrations, the raw water analyzed complies with the WHO 2017 guidelines for drinking water production, with overall good quality in terms of nitrogen pollution.