Impacts of Flash Flood on Ground Water Quality: Case Study of Central River Region, The Gambia

Abstract

Floods rank as one of the most common natural calamities, impacting the lives of millions across the globe. With ongoing population growth and expanding water and land usage, the potential for contamination and human disturbances to negatively impact water bodies continues to rise globally. This paper aims to comprehensively analyze the repercussions of floods on the groundwater quality of a region called CRR in the Gambia, during the July 2022 flood event. The focus lies on exploring the change in water quality parameters of twelve water samples from wells and boreholes through laboratory analysis of eight parameters such as pH, turbidity, temperature, electrical conductivity, total dissolved solids, nitrate, iron, sulfate, and microbial proliferation. The laboratory analysis results of the physiochemical parameters such as turbidity, and iron exceeded the safe drinking water standards set by the World Health Organization (WHO) in about 60% of the sites and fecal coliform presence in 75 % of the samples. The other parameters varied differently across all sites. However, most of the values are observed to be more prominent at the open well than borehole. The Water Quality Index (WAWQI) score also shows that 1 site has excellent water quality, 25%, has good quality and 25% has fair quality. The rest of the sites which make up 42% of the samples, are all of poor quality and unsuitable for drinking purposes. The results provide a crucial groundwork for subsequent studies targeting the water quality in this area.