A cost-optimized design framework for improved tertiary canals (mesqas) in Egypt

Egypt’s Irrigation Improvement Program (IIP) modernizes irrigation water delivery by replacing traditional mesqas (tertiary canals) with pressurized pipelines. IIP faces scalability challenges due to capital cost escalation. Previous research addressed technical performance and institutional arrangements, but absence of inflation-adjusted cost analysis integrated with hydraulic adjustments for optimized improved system remains critical gap. This study addresses this gap by developing and validating an integrated technical and financial framework using Egypt’s formal Consumer Price Index (CPI) applying projections of historical benchmark costs (2000–2016) validated through eight representative model mesqas covering 40,000 feddans and validates hydraulic performance using Darcy-Weisbach and continuity equations. Results demonstrate that traditional IIP design, when inflation-adjusted to 2025 values, costs 34,270 LE (Egyptian pound)/feddan. The optimized design, including reduced pump sizes (30/45 l/s vs. 60/90 l/s), velocity-based hydraulic criteria, and participatory earthworks strategy, achieves a 40% cost reduction to 20,560 LE/feddan, representing potential savings of 13,710 LE/feddan. Sensitivity analysis confirms that savings remain substantial (36–40%) under varying farmer participation (50–100%) and inflation scenarios (± 15%). The findings establish that the proposed optimizations represent prerequisites for program continuation. The adjustments viability depends on two enabling conditions, reliable continuous flow in secondary canals and institutionalized participatory earthworks agreements with Water User Associations.