Outdated drainage systems expose cities to flooding — GhIE
The Ghana Institution of Engineering (GhIE) has called for an urgent overhaul of Ghana’s stormwater management policies, warning that the country’s existing drainage systems are no longer capable of addressing the challenges posed by rapid urbanisation, climate variability and increasing flood risks.
According to the institution, recurring flooding in Accra and other rapidly growing urban centres had exposed fundamental weaknesses in the conventional drainage infrastructure, making comprehensive policy reforms necessary.
The GhIE in a Press statement issued in Accra yesterday and copied The Ghanaian Times said Ghana’s cities could no longer rely on traditional centralised drainage systems designed primarily to move stormwater downstream as quickly as possible as rapid urban expansion, widespread paving of land surfaces, and poor waste management practices.
“Flooding in Accra is no longer simply a seasonal occurrence. It is increasingly becoming a structural challenge driven by rapid urbanisation, loss of natural infiltration areas and fragmented management systems,” it said.
GhIE observed that flooding incidents had become more frequent and severe over the past decade, occurring even during periods of relatively low rainfall, suggesting that the problem extended beyond climate change and reflected deeper weaknesses in existing stormwater management systems.
The institution noted that many drains had effectively become conduits for solid waste, reducing their hydraulic capacity and compromising their intended function.
It further identified hydraulic constraints within the Odaw and Korle drainage system as a contributing factor to recurring flood events across parts of the capital.
The GhIE also cited institutional fragmentation as a major obstacle to effective flood management, explaining that responsibilities were spread across multiple agencies while administrative boundaries often did not align with natural drainage basins, making coordinated planning difficult.
To address the challenges, GhIE advocated a transition towards decentralised, nature based stormwater management systems that mimic natural hydrological processes.
The proposed interventions include permeable pavements, bioswales, rain gardens, green roofs, detention systems, infiltration facilities, riparian buffers and rainwater harvesting.
The institution also called for the introduction of a National Post Development Runoff Control Policy, a National Rainwater Harvesting Policy, stronger enforcement of land use regulations, protection of waterway buffer zones, catchment based planning units and increased private sector participation in green infrastructure development.
According to GhIE, adopting the measures could significantly reduce flood frequency and severity, improve water quality, lower long term infrastructure costs, create green jobs and strengthen Ghana’s resilience to climate change.
Moreover, the institution underlined that the recommendations aligned with global best practices in sustainable urban drainage and supported the achievement of the United Nations Sustainable Development Goals on clean water and sanitation as well as sustainable cities and communities.
BY STEPHANIE BIRIKORANG
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