A systematic review of the sustainability of public irrigation schemes in Ghana with focus on small scale and large-scale irrigation systems

Public irrigation schemes are vital for agricultural productivity, food security, and rural livelihoods in Ghana, yet persistent sustainability challenges including poor maintenance, inadequate financing, weak institutions, and low farmer participation undermine their effectiveness. This systematic review examines the sustainability of public irrigation schemes in Ghana, comparing small-scale and large-scale systems across the three core dimensions of economic, social, and environmental sustainability, with technical and institutional factors treated as cross-cutting enabling conditions. A structured search of Web of Science and ProQuest databases identified fifteen empirical studies meeting strict PRISMA guidelines, supplemented by review articles, book chapters, and policy reports. The findings reveal that while irrigation schemes enhance agricultural production and household income, sustainability is constrained by inadequate cost recovery (most schemes recover less than 30% of operational costs), aging infrastructure (canal conveyance efficiency ranging from 45 to 70%), land tenure insecurity, limited technical support, weak institutional coordination, and climate variability. Small-scale systems demonstrate stronger farmer participation, more effective Water User Associations, and greater local adaptability, whereas large-scale systems benefit from superior infrastructure and technical capacity but face inefficiencies in water distribution equity, governance transparency, and operational accountability. The review further identifies that small-scale irrigators achieve higher profit margins (32–45%) compared to large-scale irrigators (18–25%), while functional Water User Associations improve water distribution equity by 40–60%. To ensure long-term sustainability, the review recommends strengthening participatory management through effective Water User Associations, improving cost recovery and maintenance financing, enhancing institutional coordination, addressing land tenure and gender inequities, and promoting climate-resilient practices. These findings inform evidence-based policy formulation and irrigation investments in Ghana and similar sub-Saharan African contexts, contributing to the broader literature on sustainable agricultural water management in developing regions.