Theresa Rodriguez-Moodie | Storms are inevitable, but the scale of the devastation is not

Driving into West Green, Montego Bay, the damage from Hurricane Melissa even a month later was still unmistakable. Dried mud crusted the roadway and, in front of almost every house were piles of damaged furniture, appliances, and mattresses - markers of a night no one from the community will ever forget. A few people were outside cleaning their cars, trying to wash away the silt and debris. Many vehicles sat idle, filled with mud, no longer drivable.

From the outside, most houses looked intact, but, after climbing to the top floor of an unfinished three-storey building, we saw what the calm exterior hid. Residents said, what started as a small amount of water on floors quickly rose to waist height in less than 20 minutes. In some sections, the floodwaters covered entire ground floors up to ceilings. By morning, the water had drained away, leaving ankle-deep mud in places. The buildings stood, but many families lost almost everything.

West Green and Catherine Hall were not the only places affected. Water from the Montego, Barnett, and Pye Rivers flowed unchecked toward the coast, damaging homes, roads, and businesses along the way.

HOW DID THIS HAPPEN?

Flooding is not new to Montego Bay, but nothing on this scale had been seen before. Some suggested the flooding was directly linked to the construction of the Montego Bay Perimeter Road. But maps, speaking with residents, and seeing the extent of the damage first-hand, it seems several factors created the perfect conditions for coastal flooding. Here is what stands out for the Jamaica Environment Trust (JET) so far:

• In the days leading up to Hurricane Melissa, rainfall had already caused flooding in some areas, and the Pye River needed clearing of sediments and vegetation. From October 19 to 26, the rainfall station at Sangster International Airport recorded 26.8 mm of rain, followed by heavier rainfall of 241.6 mm between October 27 and November 1 – well above the 30-year October average of 157 mm.

• A storm surge of about three feet (0.9 metres) pushed inland up to 80 feet (24 metres) at Harmony Beach. Higher sea levels would have slowed or even halted the discharge of rivers into the sea, causing water to back up into communities.

• Construction of the Montego Bay Perimeter Road may have contributed to increased sediment loads in rivers or along their banks, constricting water flow beneath bridges and reducing the carrying capacity of the Montego and Barnett rivers.

Urgent data collection is needed to guide proper hydraulic modelling. Relief and restoration efforts take priority, but, if we want to prevent a repeat, critical flood-height measurements and other information must be gathered before clean-up erases critical evidence.

THE LESSON ON RISK

Hurricane Melissa did not hit a city unaware of its vulnerabilities and risk – Montego Bay had been warned. A 2014 study commissioned by the Inter-American Development Bank’s Emerging and Sustainable Cities Initiative identified the very areas that flooded as high-risk zones for storm surge and river flooding. The study assessed how climate change, urban development, and natural hazards overlap, and made recommendations to reduce vulnerability. One was relocating critical infrastructure and vulnerable populations out of hazard zones. Ten years later, it does not appear that these measures were carried out. The 2014 recommendations should now be reviewed against the actual damage from Hurricane Melissa, and those that still prove relevant must be implemented quickly.

A changing climate means greater unpredictability and more extreme events. In 2020, JET reviewed the Environmental Impact Assessment (EIA) for the Montego Bay Perimeter Road and expressed concern that critical hydrological assessments were missing and healthy mangrove forests could be harmed. The EIA warned that the road could either help or worsen flooding, depending on the design. The Water Resources Authority’s preliminary hydrological report identified scenarios in which the highway could worsen flooding in already vulnerable communities. To date, we have not been able to determine whether a detailed, updated hydrological assessment on the impact of the road was ever completed, or whether the EIA concerns were addressed. If such an assessment exists, did it consider extreme events like Hurricane Melissa, which science has long warned were likely?

Building in floodplains and increasing impermeable surfaces make catastrophic flooding more likely. Although the island is divided into watersheds, we do not treat them as whole systems. Rivers can become “sediment-choked” because of deforestation and development upstream. Drains, many built decades ago, have not been upgraded to handle the increased run-off and sediment.

The Jamaican state is unlikely to remove the hundreds of homes and businesses already in river floodplains. But, knowing that this level of flooding is possible, we cannot underestimate the importance of early and mandatory evacuations. So, while we may be stuck with what is already built, we should not continue to place new developments in floodplains, too close to the sea, or in other hazard-prone areas.

WHERE DO WE GO FROM HERE?

What happened in Montego Bay was not just the result of a Category 5 hurricane, but also the result of choices, omissions, and our ongoing failure to plan for the climate we now live in, not the climate we once had. The Government of Jamaica owes communities like West Green and Catherine Hall answers, transparency, and urgent action: proper investigations, stronger hydrological assessments, better land-use planning, safe, fast evacuation systems and stricter development control going forward.

Hurricane Melissa revealed the systems we neglected, both natural and human-built. The next storm will reveal whether we have acted on those lessons.

Theresa Rodriguez-Moodie, PhD, is an environmental scientist and chief executive officer of Jamaica Environment Trust. Send feedback to columns@gleanerjm.com