Long-Term Evaluation of Irrigation Water Use and Agricultural Water Productivity in a Municipality-Operated Open-Canal Scheme: Evidence from Kütahya, Türkiye

This study evaluated long-term irrigation water use and agricultural water productivity in the Kuruçay Pond Irrigation Scheme, a municipality-operated open-canal scheme located in Tavşanlı, Kütahya, Türkiye. Official institutional records for the 2012–2025 period were used to analyse irrigated crop pattern, irrigation water diverted from the source into the irrigation network, crop-based irrigation water productivity, and water economic productivity. Non-parametric trend and correlation analyses were also applied to support the interpretation of temporal changes and relationships among selected indicators. The results showed that active irrigation use remained very limited compared with the 325 ha net command area. The actually irrigated area ranged from 4.5 to 26.8 ha, corresponding to irrigation ratios of approximately 1.4%–8.2%. In contrast, source-level water delivery intensity over the actually irrigated area was relatively high in several years. Crop-based physical water productivity varied considerably among crops. Tomato showed the highest values, followed by sugar beet and potato, whereas alfalfa produced lower physical water productivity despite its important share in irrigation water use. Scheme-level water economic productivity ranged from 0.30 to 1.45 US$ m⁻³. Trend analysis did not indicate a statistically significant monotonic change in selected scheme-level indicators, while correlation results showed that water economic productivity was closely associated with water delivery intensity and crop-pattern composition. The findings indicate that agricultural water productivity in small municipality-operated open-canal schemes is shaped by active irrigation use, crop selection, plot structure, canal operation, and institutional management conditions. Short-term improvements should focus on canal maintenance, flow measurement, crop-pattern guidance, and technical support, while long-term modernization should consider land consolidation followed by a closed piped irrigation network.