This research investigates the fair and efficient distribution of water among irrigators, focusing on the timely and uniform delivery of water. To achieve this, the study utilized various methods such as group discussions, critical informant and expert interviews, and field flow measurements. The degree of fairness in the distribution of irrigation water was determined by analyzing the shift in the relative water supply to end-users. The effectiveness of irrigation is inversely proportional to the relative irrigation supply, which can be observed in the scheme's water delivery indicators. The study found that while the estimated delivered flow of water in the head, middle, and tail reaches of the canal was 1.21, 0.58, and 0.23 m3/s, respectively, the required quantity of discharge was only 0.81, 0.31, and 0.15 m3/s. This discrepancy resulted in the inadequate, unreliable, and unequal water supply to irrigators. The research revealed that canal operation and maintenance were the main factors limiting the system's capacity. The findings showed that the adequacy, dependability, equality, and efficiency values were 0.8, 0.14, 0.40, and 0.71, respectively, suggesting that improvements are needed to ensure the timely and equitable distribution of water to irrigators.

This study aims to assess the effectiveness of the small-scale irrigation schemes in Koftu, Ethiopia, in enhancing water resource utilization. The research employed various methods, including conversations, flow measurements, household surveys, and literature searches, to collect relevant information. To evaluate the performance of the irrigation schemes, performance indicators for outputs, output delivery, and financial performance were employed. The crop water requirement was estimated using CROPWAT. The results indicate that the average relative water supply and irrigation supply were 2.06 and 2.47, respectively. The output per unit-controlled area was 21094.43US$/ha, while the output per unit-cultivated area was 11212.33US$/ha. The study also found that the irrigation schemes had a high-water productivity ratio of 2.10US dollars/m3 of output and 1.02US dollars/m3 of supply per unit of water used. Additionally, the schemes showed a high level of financial self-sufficiency due to the low cost of operation and maintenance. Overall, the findings demonstrate that the small-scale irrigation schemes in Koftu, Ethiopia, have been successful in enhancing water resource utilization and improving both land and water productivity. The use of performance indicators provides a useful tool for identifying performance gaps and improvement possibilities in irrigation schemes.

As urban population numbers increase, it is evident that urbanization areas continue to expand. This expansion of urban areas mainly changes the natural land surface to the artificial landscape. The urban landscape is partly impervious, and it will decrease infiltration and in reverse increase the volume of surface runoff which causes several destructions in the town. Thus, the study was to assess the performance of the stormwater drainage system of Ambo town. The data have been used for this study were both spatial and temporal data. Rainfall data for 1987 to 2018 years and digital elevation models, land use, and soil data were used. Additionally, canal dimensions and sub-catchment data were also used. For this study, SWMM for simulating rainfall-runoff, the water level in the junctions, and flow depth in the canal were used. ARC-GIS was used to obtain spatial information and delineate the catchment of the study area. Intensity duration frequency curves of Ambo were developed using Gumbel distribution methods to analyze peak runoff for different return periods. The total runoff from the whole catchment using the rational method is 60.32m 3 /s, whereas the stormwater management model (SWMM) is 60.87m 3 /s. The model performance was evaluated using performance measuring techniques including Nash Sutcliff Efficiency (NSE) and Coefficient of Determination (R2), and the values were RNS = 0.997 and R2 = 0.997 respectively for a ten-year return period which shows the model gives good results. From simulation results, 22% of junctions are insufficient to accommodate maximum flooding, and 21% of canals are surcharged. So, from the simulation results, most of the junction and canal dimensions are insufficient to drain the generated runoff from the sub-catchments. To alleviate these problems, clearing, on-time maintenance, redesign, and constructing the adequate canal are recommended for Ambo town.

Floods are the most destructive of all-natural disasters in the globe, wreaking havoc on lives and property. Many locations in Ethiopia are experiencing flooding, and Ambo, like other tropical cities in Ethiopia, is experiencing a flash flood this can be minimized by giving attention to flood hazard measures. One of these measures is inundating flood hazard areas. Therefore, this study was conducted to map flood hazard maps along the Huluka River using GIS, HEC-HMS, and HEC-RAS in GIS environs. Flood Hazard mapping is used to define the zones which are more susceptible to flooding along the river when the release of a stream surpasses the bank-full stage along the river. The normal ratio approach was utilized to fill in missing values in precipitation data, and a double mass curve was used to ensure data consistency. Precipitation loss modeling, surplus precipitation translation to direct runoff, base flow modeling, and flood routing, the Soil Conservation Service-Curve Number, Soil Conservation Service-Unit Hydrograph, monthly constant, and Muskingum methods were used. Performance assessment approaches such as Nash Sutcliff Efficiency (NSE) and Coefficient of Determination were used to assess the model's performance (R2). During calibration and validation, Nash Sutcliff Efficiency was 0.77 and 0.7, respectively, while the coefficient of determination was 0.86 and 0.9, respectively. Flood frequency analysis was carried out utilizing the frequency storm method developed by HEC-HMS for 10, 25, 50, and 100-year return periods. For each return period, the peak flood was 38, 47, 55, and 61.5 m3/s, respectively. Using HEC-RAS and inundation areas of 98.9ha, 102ha, 104ha, and 106.4 ha, flood inundation mapping was modeled for a peak flood of each return period.