Accra faces both pluvial flooding and coastal erosion. While GARID-led (Greater Accra Resilient and Integrated Development) initiatives like bridge raising, dredging, and retention ponds provide some relief, larger structural investments are needed to combat worsening climate change, urban expansion, and waste challenges.
Commissioned by the World Bank, with GARID and Ghana’s Hydrological Service Authority as beneficiaries, this project assesses flood hazards in four Greater Accra basins. It covers both urban flash floods and coastal flooding due to erosion, informing risk mitigation strategies beyond GARID’s current scope.
HKV led the flood and erosion hazard modeling, while Deltares assessed damages and benefits of mitigation measures. Partnering with IGGS and local stakeholders, the consortium proposed strategies balancing environmental and social impacts.
Key aspects included hybrid flood mitigation strategies—community-led building protections, early warnings, and increased flood conveyance. HKV also developed a rapid erosion hazard assessment, projecting coastline changes to 2050 using satellite data. Finally, Nature-Based Solutions (NBS) were analyzed, showing stream enlargement and green buffer zones effectively reduce flooding, while rainwater harvesting does not. A sand engine is being explored to combat coastal erosion. These insights will guide future feasibility, design, and implementation efforts.
