Raphael John-Lall
As the Jamaican experience in 2025 with Hurricane Melissa shows, it is important to have effective stormwater management systems or else businesses and the economy can be affected.
Stormwater management is the effort to reduce runoff of rainwater or melted snow into streets, lawns and other sites and the improvement of water quality, according to the United States Environmental Protection Agency (EPA).
In an interview with the Sunday Business Guardian, Kiran Tota-Maharaj, Professor and Chair of Water Resources and Infrastructure at the Royal Agricultural University and the Water Research Centre Ltd (WRC) in the UK expressed this view.
In a paper published in July, he joined forces with Caribbean academics to confront the escalating climate crisis head-on.
The collaborative research team features Dr. Leighton Ellis from the University of the West Indies (UWI) Mona Campus in Jamaica, Dr. Hector Martin, a Jamaican academic based at Queen’s University, Belfast, and Professor Hazi Azamathumlla, Head of the Department for Civil and Environmental Engineering at the UWI St. Augustine Campus in Trinidad and Tobago.
The group’s collaborative paper, “Stormwater Management in Caribbean Small Island Developing States (SIDS): Societal Implications,” has now been officially accepted for publication in the journal, The Holistic Approach to the Environment.
As the Caribbean looks toward an uncertain climate future, Tota-Maharaj expressed the view that this academic paper serves as both a timely warning and an inspiring roadmap—proving that regional unity and ecological engineering innovation are the ultimate keys to safeguarding Caribbean islands’ long-term survival.
The economic cost of natural disasters in the Caribbean continues to be devastating.
In March, Jamaican director general of the Planning Institute of Jamaica (PIOJ), Dr Wayne Henry estimated that the total damage and losses associated with the passage of Hurricane Melissa in 2025 are estimated at US$12.2 billion.
This figure is equivalent to 56.7 per cent of Jamaica’s 2024 Gross Domestic Product (GDP).
Tota-Maharaj referred to the paper where they outlined the negative economic impact in the aftermath of natural disasters.
“Extreme rainfall events combine with the effects of rapid, unplanned urbanisation and surface water runoff quickly escalates from a natural occurrence into a major environmental threat. This runoff causes widespread street flooding, severe water pollution and catastrophic damage to critical infrastructure. The ripple effects are immense, compromising public health, halting commerce through business closures, and placing the heaviest societal burdens on the most vulnerable populations,” the paper stated.
Outdated infrastructure
Tota-Maharaj said the fundamental inability to cope with these increasingly frequent hydrological events stems from a critical infrastructure gap and the newly accepted research highlights that SIDS face an intensifying stormwater crisis fueled by climate change, rapid and unplanned urbanisation, fragile ecosystems, and highly constrained governance systems.
He argued that for decades, many Caribbean territories have relied on outdated, colonial-era “grey” infrastructure such as rigid concrete pipes and drains designed to rush stormwater out to sea as quickly as possible.
He then referred to the paper and what they outlined on this issue of “grey infrastructure.”
“At the core of the issue is the pervasive reliance on outdated ‘grey’ infrastructure. These systems, often comprising colonial-era pipes, culverts, and concrete drains, were designed with a singular, archaic purpose: to convey water away from built-up areas and discharge it into the sea as rapidly as possible. This approach is inherently flawed in the twenty-first century.”
In the paper, they also stated that these rigid, conventional systems offer no means for water harvesting, cannot effectively slow the flow of floodwaters to mitigate peak impacts, and crucially, provide no filtration, allowing pollutants, debris, and sediment to foul coastal waters and reefs.
“With accelerating climate change driving greater intensity and frequency of rainfall, these old systems are simply overwhelmed, making adherence to them a dangerous liability to national safety and economic stability.”
According to Tota-Maharaj and the co-authors, this approach is a dangerous liability in the twenty-first century.
Not only do these conventional hydrosystems fail to capture precious water during frequent droughts, but they also act as conduits for untreated pollutants, heavy metals, and sediment that choke fragile coral reefs and coastal ecosystems.
“Stormwater management is not an isolated technical issue, but a foundational determinant of resilience, equity, and sustainable development in Caribbean SIDS,” he said.
Adding to what they said in the paper, he noted that T&T’s infrastructure falls into the same category.
“Yes, T&T still relies heavily on traditional grey infrastructure that prioritises rapid water disposal over retention and harvesting. Across key drainage networks—such as the Caroni River basin, the South Oropouche catchment, and urban corridors in Port of Spain and San Fernando—the infrastructure predominantly consists of paved channels, concrete box drains and straightened river channels.”
He made it clear that the research carried out and identified in their framework is meant to design a “collect and convey” paradigm, quickly routing storm runoff out to the Gulf of Paria or the Atlantic Ocean to reduce immediate local standing water.
“Consequently, during intense precipitation events, millions of cubic meters of fresh water are discharged into the sea while low-lying agricultural and residential sectors suffer downstream flooding, missing valuable opportunities for storage and resource circularity.”
To move away from simple seawater-discharge networks and capture water following major storm events, he recommended that T&T can integrate Sustainable Drainage Systems (SuDS) and Blue-Green Infrastructure.
“Alternative infrastructure functional mechanisms and benefits from retention ponds and regional storage reservoirs, off-stream sustainable flood attenuation basins placed near high-volume catchments (e.g., along the foothills of the Northern Range) capturing peak runoff, allow sediment settling, and store water for emergency distribution or treatment.”
Nature-based
Tota-Maharaj calls for an “urgent paradigm shift” in looking at how stormwater is handled following natural disasters.
Rather than viewing stormwater purely as a hazard, he said the collaborative study urges a systemic paradigm shift toward treating rainwater as a vital resource.
“The paper champions the integration of Nature-Based Solutions (NbS) and SuDS—such as permeable pavements, bioswales, rain gardens, green roofs, and the restoration of natural mangroves and wetlands. These interventions collectively slow, spread, soak, and filter water while replenishing threatened freshwater aquifers.”
He then pointed to what the paper said.
“Unlike concrete-bound grey systems, NbS are systems that utilise or mimic natural processes to manage water. Examples include the installation of green roofs to absorb rainfall, the use of permeable paving and roadside swales to encourage infiltration, and the construction of wetlands to filter runoff. These solutions work by introducing multiple strategic interventions across the landscape that collectively slow, spread, soak, and filter water. They treat rainwater as an asset rather than a waste product.”
Human and economic toll
Tota-Maharaj said the research underscores that poor stormwater management triggers a compounding chain reaction across Caribbean societies.
He used public health emergencies as an example.
“When extreme rainfall mixes with sewage and solid waste, floodwaters rapidly become vectors for deadly waterborne and vector-borne diseases, including leptospirosis, dengue, Zika, and gastroenteritis.”
He then spoke about severe economic disruption as being another consequence of poor management.
“Climate shocks and chronic flooding routinely devastate tourism—a sector accounting for up to 40 per cent of GDP in some SIDS—while erasing national GDP and forcing governments into high-interest borrowing for emergency reconstruction.”
He added that there is profound social injustice when governments mismanage the aftermath of natural disasters.
“Low-income households and informal settlements located on steep, erosion-prone slopes or vulnerable gullies bear the brunt of environmental disasters, facing recurrent destruction with little to no safety nets.”
