Research Data Supporting: Legal and Institutional Coherence in Flood Risk Governance – Empirical Evidence from Lagos Metropolis

This dataset contains all empirical data generated during the doctoral research study on legal and institutional coherence in flood risk governance across four local government areas (LGAs) in Lagos Metropolis, Nigeria: Apapa, Victoria Island, Eti-Osa, and Ikeja. Data were collected between October 2023 and December 2024 using a mixed-methods design integrating four instruments: (1) systematic documentary legal analysis of 21 primary governance instruments, including the Nigeria Climate Change Act 2021, National Disaster Risk Reduction Policy 2020, National Development Plan 2021–2025, Nigeria Agenda 2050, and the full suite of Lagos State flood management statutes; (2) semi-structured key informant interviews with 47 participants drawn from federal agencies (NEMA, NIHSA, Federal Ministry of Environment, Dept. of Climate Change), Lagos State ministries (LASEMA, LASEPA, Ministry of Physical Planning, Ministry of Works), LGA environmental and planning units, civil society organizations, and community representatives; (3) a structured household survey administered to 100 residents in flood-affected communities using stratified random sampling proportional to population size and flood exposure severity; and (4) a systematic review of 150 building permit files from the Lagos State Physical Planning Permit Authority (LASPPPA) issued between January 2020 and December 2023. The dataset documents three interlocking governance failure dimensions: vertical coherence deficits (flood mandates distributed across 23 agencies with no statutory joint planning requirement); horizontal coherence failures (77% of building permits in flood-prone zones carried no flood risk assessment; 0% showed mandatory inter-agency consultation); and temporal coherence gaps (no multi-year fiscal instrument links Nigeria Agenda 2050 flood targets to annual Lagos State budget cycles). It also provides pilot evidence from the Integrated Flood Management Coherence Framework (IFMCF), which achieved a 75% improvement in policy translation speed and a 60% reduction in inter-agency coordination time in Ikeja and Eti-Osa pilot areas. Community Flood Committees attracted over 2,000 members in pilot areas, and communities with active committees reported 60% lower flood impacts in the 2024 rainy season relative to the 2023 baseline. The dataset underpins all empirical claims, tables, and quantitative indicators in the associated article.