GCA advances Nature-based Solutions to curb flooding and erosion in the Republic of the Congo
B
razzaville, Republic of the Congo, 10 October 2025 – From 1–3 October 2025 in Brazzaville, the Global Center on Adaptation (GCA) and its consortium partners convened a national validation workshop for the Republic of the Congo’s Inventory of Nature-based Solutions (NbS), with a dual purpose: validate the Inventory and deliver targeted capacity building for national and city stakeholders. The event brought together national ministries, the municipalities of Brazzaville and Pointe-Noire, water and sanitation utilities, community leaders, academia, civil society, and the World Bank. This initiative—delivered in collaboration with the World Bank and with support from the Ministry of Foreign Affairs of Denmark (DANIDA)—is part of GCA’s technical support to the World Bank-financed Congo Strengthening Urban Resilience Project, which aims to improve access to climate-resilient basic urban services and increase resilience to erosion and flood risks in Brazzaville and Pointe-Noire.
The Republic of the Congo is highly vulnerable to climate change and faces significant capacity constraints as a fragile, conflict-affected state. While local nature-based practices exist, they remain small-scale. In Brazzaville and Pointe-Noire—home to nearly 60% of the population—more intense and erratic rainfall is driving urban flooding and accelerating gully erosion, often in informal settlements on steep slopes and floodplains. This context underscores the need to validate practical NbS options and build the capacity to implement them at scale. The NbS Inventory documents local NbS practices that could be scaled up to mitigate the twin challenges of flooding and erosion. Prioritized solutions will be compiled into a Compendium of NbS Investments, which will include pre-feasibility level designs to guide government and World Bank investments.
Workshop objectives, key findings, and next steps
Over three days, plenary sessions and field visits were used to validate the Inventory, refine neighborhood use cases, prioritize candidate practices and sites for inclusion in the Compendium and clarify operations-and-maintenance arrangements. The workshop also delivered targeted capacity building in hazard assessment, co-design of hybrid “grey + green” NbS packages, and operations-and-maintenance planning (including basic costing and monitoring), to help participants cascade these skills within their institutions and communities.
The workshop highlighted the effectiveness of hybrid “grey + green” approaches—pairing engineered drainage and gabions with vetiver, bamboo and agroforestry—for erosion control and runoff management (including around the Ngamakosso water tower); the importance of clear O&M roles with simple checklists to sustain benefits; the value of women’s and youth participation at Don Bosco for stewardship and replication; and the need to address data gaps (hydrologic baselines, erosion mapping, local nursery supply, and cost parameters) to inform pre-feasibility.
The workshop concluded with a refined shortlist of NbS for priority urban areas and an agreed roadmap for technical assistance, training, and data collection. Building on these outcomes, GCA and partners will finalize the Compendium of NbS Investments, continue community-focused capacity building, and support national and city authorities to integrate priority solutions into project pipelines. By building on existing solutions, the Compendium emphasizes context-specific measures that yield multiple co-benefits, and are therefore more likely to be sustained over time–especially in fragile settings with limited institutional capacity.
