Accra’s Flat Landscape Means Bigger Drains Alone Cannot Stop Flooding, Engineer Warns

Engineer and policy analyst Michael Kosi Dedey has called for a major rethink of Ghana’s flood management strategy, arguing that simply expanding drainage infrastructure will not solve Accra’s recurring flooding problem.

Speaking on The Big Issue on Channel One TV, Mr. Dedey said the capital’s geography makes it impossible to rely solely on drains to manage increasingly intense rainfall. He stressed that Ghana must shift towards a broader flood management approach that prioritises water retention, storage and long-term urban planning.

According to him, recent flooding events demonstrate that climate patterns have changed significantly, requiring engineers and policymakers to rethink traditional drainage designs.

“Accra is technically a flat-lying area,” he explained. “When land is flat, water cannot move quickly enough through drains regardless of how wide they are.”

Mr. Dedey noted that stormwater naturally depends on gravity to flow into rivers and eventually into the sea. However, Accra’s relatively flat terrain slows this process, causing water to accumulate rapidly during heavy downpours.

He argued that this makes it unrealistic to expect drainage channels alone to eliminate flooding across the city.

Instead, he called for investments in infrastructure capable of temporarily storing excess rainwater before gradually releasing it into natural waterways.

According to the engineer, modern flood management should combine drainage expansion with detention ponds, retention reservoirs, wetlands and other water storage systems that reduce pressure on existing drains during extreme rainfall.

He also warned that climate change is introducing new challenges that many existing drainage systems were never designed to handle.

One of those challenges, he explained, is rising sea levels.

Mr. Dedey questioned the long-held assumption that stormwater discharged from Accra’s drains will always flow freely into the Gulf of Guinea.

He warned that when sea levels rise during storms or periods of high tide, seawater can slow or completely block the discharge of stormwater, forcing floodwaters back into communities.

“When the sea level rises, water cannot discharge efficiently,” he explained. “Instead, it backs up into already flooded areas, making the situation much worse.”

To illustrate his point, Mr. Dedey referred to the devastating June 3, 2015 floods, one of the deadliest disasters in Ghana’s recent history.

He said elevated sea levels during that event significantly reduced the ability of stormwater to flow into the ocean, contributing to severe flooding across parts of Accra.

The engineer believes similar conditions continue to threaten the capital, particularly as climate change increases both rainfall intensity and sea level rise.

His comments come after recent flooding across Greater Accra resulted in widespread destruction, displacement of residents and loss of lives, renewing debate over Ghana’s flood preparedness and urban planning policies.

Mr. Dedey maintained that future flood mitigation projects must move beyond simply constructing larger drains.

He urged authorities to integrate climate resilience into infrastructure planning by preserving natural waterways, protecting drainage buffer zones and creating additional facilities capable of storing excess stormwater during periods of intense rainfall.

He also stressed the importance of enforcing planning regulations to prevent construction within waterways and flood-prone areas, noting that unchecked urban development continues to reduce the city’s natural drainage capacity.

According to Mr. Dedey, solving Accra’s flood challenges will require coordinated action involving engineers, urban planners, environmental experts and policymakers.

He said a comprehensive strategy that combines improved drainage, water retention systems, sustainable land use planning and climate adaptation measures offers the best chance of reducing flood risks in the long term.

As Ghana continues to experience more frequent extreme weather events, the engineer believes embracing modern flood management practices will be essential to protecting lives, infrastructure and economic activity across the capital.