Evaluation of groundwater quality for drinking and irrigation purposes in the Gidabo watershed, Ethiopia

Evaluating groundwater quality for drinking and irrigation is vital because it ensures safe drinking water for humans and promotes agricultural sustainability. However, research on this aspect in the Gidabo watershed is limited. The purpose of this study was to evaluate groundwater quality and ascertain its suitability for drinking and irrigation. A total of 30 groundwater samples were collected from 15 sampling points, including boreholes, springs, and dug wells, during the rainy season (October 2024) and the dry season (January 2025). The water quality index (WQI) was used to assess the suitability of groundwater for human consumption. On the other hand, the appropriateness of groundwater for irrigation was evaluated by estimating the sodium adsorption ratio (SAR), permeability index (PI), salinity hazard (SH), Kelley index (KI), exchangeable sodium percentage (ESP), residual sodium carbonate (RSC), magnesium adsorption ratio (MAR), and irrigation water quality index (IWQI). According to the WQI analysis, 80 % of the samples were safe for drinking. However, water quality was poor in samples from the DW source (due to high iron levels) and the BH-7 source (due to high fluoride levels). According to the IWQI analysis, 93.33 % of the groundwater samples were appropriate for unrestricted irrigation. This study is vital for policymakers and environmentalists to develop strategies for long-term groundwater utilization and water quality preservation.