Tue | Sep 19, 2017

Martin Henry | Duelling disasters

Published:Monday | June 5, 2017 | 6:00 AM

On the night of August 14, 1933, Kingston and lower St Andrew experienced record flooding that killed 53 people and destroyed more than £300,000 of public and private property.

The flooding was triggered by heavy rains that had been falling for several weeks, causing the gully courses to overflow their banks, sweeping away houses with their occupants. Five inches of rain fell in one hour and the rainfall for the day was 11.60 inches (The Gleaner Geography and History of Jamaica).

It is not likely that death and destruction of property on such a scale from flooding will occur on the Liguanea Plains again. For one thing, we have better warning systems. But also the Sandy Gully network criss-crossing the plain has been tamed and rainwater runoff is safely channelled into Kingston Harbour.

People using bridges over the paved and walled Sandy Gully or the paved fords sort of treat these as part of the natural landscape that has been there from Adam, or at least from the time of the Tainos.

But from the days of Bustamante's 'Gully Government' in the 1940s, and deeper back into colonial times, there has been a massive buildout of protective infrastructure like sea walls, retaining wall, drains and paved gullies.

The fact of the matter is that with sufficient intensity of a natural hazard event, even the best human defence systems can and will be overwhelmed. Advanced Europe has been faced with catastrophic flooding in recent years, for example. Dozens have died.

 

FORCED RESETTLEMENT

 

In the aftermath of the May floods, Prime Minister Holness has come out proposing resettlement from high-risk areas, by which he means riverbeds, gully banks and steep hillsides. The people who live in these places have been pushed there not so much by choice or the love of danger, but by the facts of our post-Emancipation history with the deliberate strategy of the plantocracy to keep the ex-slave, labouring class off 'good' land and in perpetual servitude. People can't simply be ordered out of danger without somewhere to go.

But where is safe? Jamaica faces a number of natural hazards imposed by its geography and geology as a largely mountainous piece of land surrounded by the sea in the Atlantic-Caribbean hurricane belt. Our big hazards are the floods and landslides from high-intensity rainfall, hurricanes with wind damage and the risk of sea surges, and we may be forgetting earthquakes because we haven't had a major hit for a long time. The last biggish hit that caused any deaths, only three, was way back in 1957 and was centred in the west.

With the right intensity and positioning of a natural hazard event, any area considered safer from one risk can be in danger from another. A sufficiently big earthquake with a properly positioned epicentre can cause the alluvial Liguanea Plains, with the capital city Kingston sitting on it, to behave like liquid with waves undulating through it like ocean waves.

 

POTENTIAL DANGERS

 

It may well be found then that rigid, hurricane-resistant buildings will fare badly in such a major quake. Surrounding elevations like Jacks Hill and Beverley Hills, on which the prime ministerial mansion sits, are known to be geologically unstable and could quite literally 'walk' in a well-positioned major quake.

The country is riddled with geological fault lines, some of which you can see as gashes in the earth, like those around the Stony Hill-Mannings Hill area and into the Wag Water River valley. We sit on the same fault line on which the massive 2012 earthquake in Haiti occurred.

Of course, we want to minimise, to mitigate, the disaster impact of natural hazards event. So we have to build the drains, keep them clean, and carefully study how shifting land use and construction and infrastructure may be exacerbating natural hazard events. Progress and development always come with a price tag.

We want a disaster-sensitive building code that sensibly balances costs and safety. We want to move people out of areas flooded by every little rain and which are very high risk for landslides. But Government is not God, which is not for want of wishing and trying on their part and demand by the people. At the end of the day, a sufficiently intense natural hazard event will breach human protective defences. With expectations tempered by reality, we also have to work hard at recovery strategies.

- Martin Henry is a university administrator. Email feedback to columns@gleanerjm.com and medhen@gleanerjm.com