Abstract
Urban flooding has become one of the most persistent environmental challenges confronting Lagos, Nigeria’s largest metropolitan area. Rapid urbanization, inadequate land-use control, weak institutional coordination, and climate-induced extreme rainfall events have intensified flood risks, resulting in recurring socio-economic losses and infrastructural damage. While several flood mitigation initiatives have been implemented in Lagos, the effectiveness of these interventions largely depends on the quality of environmental governance and the strategic involvement of development agencies. This study examines the role of environmental governance frameworks and development agencies in mitigating urban flooding in Lagos, with emphasis on institutional coordination, policy implementation, and capacity-building efforts since 2020. The study adopts a quantitative research approach, utilizing structured questionnaires administered to key stakeholders, including government officials, urban planners, environmental professionals, and development practitioners involved in flood management initiatives in Lagos. Data collected were analyzed using descriptive statistics to assess perceptions of governance effectiveness, inter-agency collaboration, and the impact of development agency interventions on flood mitigation outcomes. Findings reveal that while development agencies have significantly contributed to funding, technical support, and policy advisory services, challenges such as fragmented institutional responsibilities, limited enforcement capacity, and inconsistent policy implementation continue to undermine long-term flood resilience. The study concludes that strengthening environmental governance through improved coordination mechanisms, clearer institutional mandates, and sustained capacity development is essential for enhancing the effectiveness of development agency-led flood mitigation initiatives. The research provides policy-relevant recommendations aimed at improving governance structures and aligning development agency interventions with local institutional realities to promote sustainable urban flood management in Lagos.