Environmental engineer, Dr. Juliet Ohemeng-Ntiamoah, has challenged the growing narrative that indiscriminate waste disposal is the primary cause of Ghana’s recurring floods, arguing instead that the country’s flooding crisis stems from deeper structural and planning failures that require long-term engineering solutions.
Speaking on JoyNews’ Newsfile programme on Saturday, July 11, Dr. Ohemeng-Ntiamoah cautioned against what she described as an increasing tendency by government officials to elevate poor sanitation as the dominant explanation for flood disasters.
“My main concern is that through the commentary from the presidency and other government officials during and after the flood, it appears that we are elevating indiscipline or indiscriminate waste disposal as a major cause of the flooding, and I beg to differ with that,” she stated.
While acknowledging the importance of maintaining clean communities, Dr. Ohemeng-Ntiamoah argued that regular clean-up exercises and communal labour should not be mistaken for sustainable flood management strategies.
“I think we all agree that this clean-up is not a solution at all,” she said.
According to her, communal labour plays an important role in promoting community ownership and social cohesion but offers little in addressing the systemic weaknesses in urban sanitation and stormwater management.
“Communal work is good for community building and ownership, but when it comes to waste management or improving sanitation in the city, this does not solve it,” she explained.
Instead of relying on periodic cleanup campaigns after major flooding incidents, she urged policymakers to adopt evidence-based engineering and planning approaches that address the root causes of urban flooding.
Central to Dr. Ohemeng-Ntiamoah’s recommendations is the need for Ghana to redesign its drainage infrastructure using internationally accepted standards that account for increasingly extreme weather events.
“We need to rethink our drainage system and be considering a 100-year flood,” she said.
She explained that designing for a 100-year flood means constructing drainage systems capable of managing flood events with a one per cent probability of occurring in any given year.
According to the environmental engineer, many cities around the world have already adopted this principle as part of climate-resilient urban planning, enabling them to withstand increasingly intense rainfall associated with climate change.
She stressed that Ghana must begin planning beyond current rainfall patterns if it hopes to build resilient cities capable of coping with future extreme weather events.
Beyond drainage infrastructure, Dr. Ohemeng-Ntiamoah identified increasing stormwater runoff resulting from rapid urbanisation as another major contributor to flooding.
She explained that effective stormwater management begins with reducing the volume of runoff entering drainage systems.
“The first thing you need to do is to reduce runoff,” she noted.
However, she observed that urban development across many parts of Accra has replaced natural surfaces with concrete pavements, tiled compounds and other impermeable materials that prevent rainwater from infiltrating the soil.
“Currently, we have a lot of developments that are all tiled, concrete and really increase this runoff,” she said.
The resulting surge in surface water, she explained, places enormous pressure on drainage infrastructure, increasing the likelihood of flooding during heavy rainfall.
Dr. Ohemeng-Ntiamoah also questioned the common description of flood-prone developments as simply “building in waterways.” Instead, she argued that the issue should be viewed as a broader failure to protect wetlands and other natural ecosystems that serve as critical flood buffers.
“We have lack of enforcement in protecting our wetlands, which people term as building in waterways, but I prefer to call it lack of enforcement in protecting our wetlands,” she stated.
Wetlands naturally absorb excess stormwater and reduce flood peaks. Their destruction through unregulated development, she argued, has significantly weakened the country’s natural flood protection systems.
She also pointed to the absence of sufficient detention points—areas designed to temporarily store stormwater before gradually releasing it into drainage systems—as another weakness in Ghana’s flood management strategy.
Addressing another widely held perception, Dr. Ohemeng-Ntiamoah argued that clogged drains are caused primarily by accumulated silt rather than plastic waste.
According to her, close observation of drainage channels reveals that sediment build-up is often the first obstruction that reduces drainage capacity.
“If you pay careful attention to the drainages that we have and what is choking them, you will realise that it is silt primarily before even waste,” she explained.
She noted that once drains become filled with sediment, plastic bottles and other waste materials become trapped, worsening blockages and reducing the flow of stormwater.
“Without silt occupying the gutters, the plastic bottles all will float, but it is the silt that is trapping all these waste in the gutters,” she added.
