Hydrological analysis of stream flow in the Awetu River, Ethiopia

The minimum and maximum river flows are influenced by the magnitude and frequency of stream flow events, making it essential to assess these factors when planning and developing water resource projects. Given the serious consequences of water scarcity, low flow conditions have become increasingly recognized as critical. It is important to estimate low flow levels at various points along a river. In the case of the Awetu River, concerns have arisen regarding the sustainability of future water withdrawals both in terms of quantity and quality due to rapid population growth in Jimma. Understanding the specifics of river low flows is vital for effective water resource management. The findings indicate that the (Baseflow Index, BFI) of Awetu River is 50.3%, with a trend (τ) of 0.117. The seven-day minimum flow (7Q10) is recorded as 0.1 m3/s, while total stream flow measures 12,120 m3/s and baseflow as 6,095 m3/s. The 7Q10 data fits a lognormal distribution, which ranks it first among the other distribution. Trend analysis conducted using the Mann–Kendall test reveals a slight positive trend in the seven-day minimum flows. These results provide essential baseline information for drought management, water allocation, and the planning of hydraulic structures within the Awetu watershed.