Groundwater flow dynamics and sustainable management in the Kobo Valley, Ethiopia

Abstract

Groundwater is a critical resource that underpins water security, but it is increasingly threatened by climate variability and growing anthropogenic pressures. In the Kobo Valley of Ethiopia, groundwater serves as the principal source of water for domestic and irrigation purposes, raising serious concerns about the sustainability of the aquifer. This study evaluates groundwater flow dynamics and provides insights for sustainable groundwater management in the region. A numerical groundwater flow model was developed using Visual MODFLOW Flex (MODFLOW 6), with key hydraulic parameters derived from pumping test data analyzed through Aquifer Test. Model simulations revealed seasonal groundwater-level fluctuations of up to 1.7 m along the eastern boundary and 1.4 m along the southern boundary. Scenario analysis indicated that a 50% reduction in pumping rates could effectively mitigate groundwater-level decline, limiting drawdown to 1.5 m during irrigation periods. These results demonstrate that the Kobo Valley aquifer is highly susceptible to over-extraction, emphasizing the importance of optimized pumping regimes, artificial recharge interventions, and continuous monitoring. The findings offer critical guidance for sustainable groundwater management and support the formulation of evidence-based water resource policies in Ethiopia.