Environmental degradation caused by poor road drainage systems is increasingly affecting communities across Rwanda, according to a recent assessment by Transparency International Rwanda (TI-Rwanda). The study found that despite existing Environmental Impact Assessment (EIA) requirements, some road projects have design flaws, insufficient hydrological analysis, and weak construction supervision, leading to recurring drainage failures.
The affected districts include Karongi, Muhanga, Nyamagabe, Huye, Nyaruguru, Gisagara, Nyagatare, Kirehe, Ngoma, and Bugesera. The absence of effective drainage infrastructure on multiple road segments has created serious environmental, social, and safety hazards in these communities. The social, economic, and environmental effects experienced include blocked, undersized, or misaligned culverts, stagnant water accumulating in roadside depressions, and high-velocity water flow that can sweep individuals or livestock.
Abias Maniragaba, Senior Project Coordinator at TI-Rwanda, noted that the challenges reflect a broader structural problem in road design, maintenance, and compliance across Rwanda. The report highlighted specific cases, such as the Karongi-Muhanga road, where the absence of side drains and culverts accelerates gully formation, and the Huye-Ndago Road, where high-velocity water cuts into farmland, reducing crop yields and generating sediment loads downstream.
To address these issues, experts have proposed engineering solutions, including redesigning and upgrading culverts based on updated hydrological data, installing stormwater management systems, and developing drainage master plans for all new road projects. Strengthening institutional arrangements, such as mandating independent environmental audits and introducing contractor accountability frameworks, has also been recommended.
The Rwanda Transport Development Agency (RTDA) has initiated a countrywide mapping of road drainage issues and has begun pilot works on selected priority sites, including those along the Muhanga-Ngororero-Mukamira and Gisiza-Pfunda roads. The interventions involve installing stronger foundations with layered stone structures, water-resistant materials, and wider concrete-reinforced drainage channels to ensure long-lasting resilience against climate-related shocks.
Gemma Maniraruta, Director General of Water and Sanitation at the Ministry of Infrastructure, emphasized the importance of incorporating proper road drainage from the earliest design stage, citing visible benefits from this approach. She recommended that TI-Rwanda submit its report and recommendations to the Ministry of Infrastructure to ensure the next phase of implementation. The effective implementation of these measures is crucial to protecting receiving waters and wetlands, and to mitigating the environmental, social, and economic impacts of poor road drainage systems in Rwanda.