Irrigation development and sustainable water management in Rwanda (2010-2024): spatial assessment and crop water requirement analysis.

This study examines irrigation development and sustainable water management in Rwanda under the 2010 and 2020 National Irrigation Master Plans. Using national datasets, QGIS spatial analysis, and CROPWAT 8.0 modelling for maize at the Mpanga Hillside Irrigation Scheme, we evaluated irrigation expansion (2010-2024), technology adoption, and irrigation water demand projections to 2050. By 2024, the total irrigated area reached 72,913 ha, merely 14.5% of the national irrigable potential of 501,509 ha, with around 70% of equipped areas using low-efficiency traditional systems (50-60% water use efficiency). Marshland, hillside, and small-scale irrigation schemes showed uneven growth, heavily constrained by funding shortages, COVID-19 impacts, and inadequate infrastructure maintenance. Eastern catchments, including Muvumba, Upper Akagera, and Lower Akagera, face acute water stress, with irrigation demand projected to surge toward renewable water limits by 2035-2050. The peak irrigation requirement for maize at Mpanga was 230.8 mm per decade. Core constraints include financial limitations, inefficient technologies, and spatial mismatches between water demand and supply. We recommend scaling water-saving technologies, strengthening water user associations, tiered water pricing, and smart precision irrigation. Future research should explore treated urban wastewater reuse to support climate-resilient and sustainable agricultural development in Rwanda.