Report

Hybrid Infrastructure for Urban Flood Risk and Climate-Related Hazard Management in Sekondi-Takoradi, Ghana

An economic valuation of the use of nature-based infrastructure for flood resilience

Flooding in Sekondi-Takoradi, Ghana, is becoming more frequent and intense due to climate change and rapid urbanization, placing critical pressure on local infrastructure and communities. This Nature-Based Infrastructure (NBI) Global Resource Centre report assesses the social, environmental, and economic outcomes of interventions aimed at improving flood resilience and compares a business-as-usual scenario with a hybrid approach (nature-based and grey infrastructure).

By Nathalia Niño, Marco Guzzetti on May 22, 2025

Download from NBI Global Resource Centre

Key Findings

The project demonstrates exceptional economic viability, with every USD 1 invested yielding returns between USD 3.26 and USD 13.53. This performance, marked by high internal rates of return and substantial net benefits, signals a highly profitable and sustainable approach to climate resilience.
The primary driver of economic benefits stems from avoided flood damages and infrastructure maintenance costs, underscoring the critical role of hybrid nature-based and grey infrastructure solutions in safeguarding community assets and bolstering flood protection.
Beyond direct economic gains, the assessment highlights significant co-benefits crucial for holistic sustainable development that provide essential data for decision-makers in Sekondi-Takoradi, enabling them to secure vital funding and align local policies with climate priorities.

In Sekondi-Takoradi, Ghana, climate change and rapid urbanization have increased the frequency and severity of flooding, causing widespread damage to homes, infrastructure, and ecosystems. Heavy rains frequently overwhelm the city’s drainage systems, cutting off communities and threatening lives and livelihoods—especially in vulnerable low-lying areas.

In collaboration with the Covenant of Mayors in Sub-Saharan Africa, the NBI Global Resource Centre assessed the social, environmental, and economic outcomes of interventions aimed at improving flood resilience in Sekondi-Takoradi. The assessment compares a business-as-usual scenario with a hybrid approach (nature-based and grey infrastructure), with a focus on two priority locations—Sekondi Market and Bakado—that are highly exposed to flood risks.

The project valuation quantified the environmental, social, and economic impacts of the proposed hybrid interventions, which include wetland restoration, tree planting, green space development, urban gardens, and improved drainage systems.

Using spatial modelling, climate scenarios, and cost-benefit analysis, the valuation estimated the benefits of implementing the hybrid infrastructure compared to a no-action scenario, including:

increased water retention and reduced flood damage
increased carbon sequestration
improved health outcomes and air quality
increased land valuation
reduced infrastructure maintenance due to flood damage
local job creation and skills development

Results indicate that for every USD 1 invested in hybrid infrastructure, the project returns between USD 3.26 and USD 13.53, depending on the flood valuation (low, high or average economic value). The avoided costs from flood damage are the primary driver of economic benefits, ranging from USD 163.29 million in the scenario with limited floods to USD 747.11 million in the scenario with severe flood damage.

The results will support Sekondi-Takoradi Metropolitan Assembly and its partners in making informed investment decisions, aligning local policy with climate priorities, and potentially securing funding for future implementation.