Josephine Tetteh , Dacosta Aboagye, Edmund. I Yamba, Joseph Alhassan, Samuel Bichakinag Kunji, Stephen Asare , Andrews Ofosu, Daniel Buor

The Nasia river serves as the primary source of domestic water supply for over 5000 households in the Nasia catchment. However, the river is currently experiencing water stress conditions, causing an imbalance between the demand for water and the available supply. In this study, we evaluated the impact of climate and environmental factors on changes in domestic water supply in the Nasia catchment, with the ultimate objective of providing policy direction. Our approach involved a mixed model of analyzing local perception of the drivers of domestic water supply change through focus group discussions and statistical analysis of in-situ climate and environmental data. Analysis of the local perception revealed that supernatural and mystic beliefs, changes in seasonal rainfall and environmental degradation were the causes of change in domestic water supply at the catchment. The statistical analysis of in-situ climate data revealed that mean and maximum temperatures were the main drivers, accounting for over 40% of the change in domestic water supply. Long term trends in temperature revealed positive trends with an indication of pre-warming of about 1.5oC of the catchment. Analysis of land use/cover change revealed that built-up/bare land has increased by 58.44% whereas farmland, vegetation, and water have reduced by 34.10%, 22.85%, and 1.48% respectively. The increase in bare lands had significant influence on the rate of warming and evapotranspiration in the Nasia catchment. The study’s outcomes hold significant practical relevance for Ghana’s Water Resources Commission and the Water and Sanitation Agency sector, as they endeavour to meet the nation’s water-related targets and sustainable development goal six. Additionally, it will offer valuable guidance for climate service provision and Nasia river catchment protection, as well as the implementation of alternative water sources to complement its usage.