Evaluation of the performance of DSİ 18th regional irrigation networks

In this study, the performance of 21 irrigation networks operating under the responsibility of the DSİ 18th Regional Directorate was evaluated for the period between 2017 and 2023 using selected performance indicators. The analysis was based on data obtained from DSİ's annual operation and monitoring reports, including irrigation area, irrigated area, and relative water supply. Performance evaluation focused on indicators such as the amount of water delivered per unit area, water supplied per irrigated area, relative water supply, and interannual variability. The results of the statistical analyses indicate that the performance of the irrigation networks in the DSİ 18th Region is not homogeneous. While water distribution levels were relatively high in networks such as Boğazova, Çavdır, Seyitler, Selevir, and Yılanlı, they remained low in Karaçal, Köprüköy, and Şehit Hüseyin irrigation schemes. Significant interannual fluctuations suggest that water availability in the region is influenced by both climatic conditions, particularly precipitation and temperature, and the operational and managerial capacities of irrigation associations. Moreover, excessive water use observed in certain irrigation networks during some years poses risks in terms of efficiency and sustainability. This study presents a comprehensive evaluation of the performance of irrigation networks in the DSİ 18th Region using multi-year data and identifies their strengths and weaknesses from a regional water management perspective. The findings indicate that the expansion of modern irrigation methods, the regular implementation of maintenance and rehabilitation activities, and the alignment of cropping patterns with available water resources are critical for improving irrigation efficiency. In this respect, the study contributes to decision-support processes for the evaluation of irrigation network performance in the DSİ 18th Region.