Rethinking the modernization of pressurized networks: Lessons from a case study in the Gharb (Morocco)

International audience

English. Irrigation modernization aims to improve water efficiency and reduce energy costs while ensuring the long-term sustainability of irrigation systems. However, restricted investments, and standardized management often create technical and economic constraints that limit farmers' ability to adapt irrigation methods to their needs. This study examines the 2012 collective drip irrigation project in the Gharb irrigation scheme (Morocco), adaptation of a previous existing network, which sought to replace sprinkler irrigation with drip irrigation to improve water and energy use. Despite initial adoption, 48 % of farmers reverted to sprinkler irrigation due to pressure deficiencies, soil constraints, and financial barriers. By means of an original methodology supported by hydraulic modeling and design tools (Gestar®) and field data collection, we evaluated alternative network operational conditions and infrastructure modifications to improve system reliability. The findings show that allowing farmers to combine drip and low-pressure sprinkler irrigation enhances flexibility while restraining water and energy use. Improving network performance requires resizing bottleneck pipes and adjusting head at pumping station, ensuring sufficient pressure at outlets for nominal conditions. These modifications must be economically viable, requiring cost-benefit analyses to balance infrastructure investments with long-term affordability. Beyond technical adjustments, the study highlights the importance of negotiation and participatory governance in irrigation modernization. While this case focuses on the Gharb region, the research approach, the challenges of infrastructure limits, adaptation strategies, and governance gaps are relevant to irrigation modernization worldwide. Ultimately, modernization should support farmer-centered irrigation systems, ensuring economic feasibility, resource efficiency, and adaptability to future challenges.