Nature-based solutions for reducing flood risk:A case study in South Tongu District, Ghana

Flooding poses a significant threat to socio-economic and ecological systems in Ghana, particularly in rural districts such as South Tongu. Conventional flood management strategies have proved inadequate in addressing recurrent and severe flooding in the region. This study investigates the effectiveness and practicality of implementing Nature-based Solutions (NbS) for flood risk management in South Tongu District, Ghana. Using a mixed-methods approach, the research integrates spatial analysis, hydrological modelling via the fast flood model, and expert interviews to assess flood-prone areas, evaluate selected NbS interventions, and examine implementation feasibility.<br/><br/>Three NbS, permeable surfaces, river restoration, and riparian/forested buffers, were selected based on literature review and local applicability. The fast flood model was used to simulate baseline and intervention scenarios. Results indicate that all three measures reduced flood extent, depth and affected buildings, with river restoration showing the most significant reduction. Permeable surfaces were most effective in built-up areas, while riparian buffers contributed to reduced runoff and erosion along riverbanks.<br/><br/>Expert interviews revealed key practical challenges, including high initial costs, limited stakeholder awareness, and weak institutional coordination. Nonetheless, local soil conditions and vegetation support the feasibility of NbS integration, provided site-specific adaptations are made. The study concludes that NbS offer a viable and sustainable alternative to traditional flood management approaches in rural Ghana. By aligning ecological restoration with risk reduction, these interventions support the achievement of SDGs related to climate resilience, sustainable cities, and land use. Recommendations are made for policy integration and scaling up NbS across similar vulnerable regions.