NASSAU, BAHAMAS — Storm surge is a nightmare during any hurricane season and as Hurricane Ian passed near The Bahamas there was a threat of severe coastal flooding.
Wave energy from strong swells can cause severe damage to infrastructure; and while there are seawalls in certain parts of the country that help buffer the sea, many areas are still in harm’s way.
Coastal Engineer at BRON Ltd. Carlos Palacious says the issue can be tackled in a number of ways in order to “engineer ourselves for survival”.
“We can look obviously at other nations who have successfully been dealing with these challenges in the past. Places like Mexico City, which a lot of which are under or below sea level,” he said.
“Places like parts of Venice, as well as the Netherlands that are under or below sea level and look and see what has been successfully done and what we can implement.”
The coastal engineer explained that these issues are often classified as green or softer solutions or grey which are harder solutions. He added that in the case of the capital where the majority of the population resides, grey infrastructure like sea walls may be a better solution, seeing that a lot of the coastlines are occupied by buildings leaving little space to accommodate greener solutions.
Palacious continued: “We only populate somewhere around three percent of our land… technically we have a lot of land, but most of us are concentrated in New Providence.
“So if we talk strictly about the property where land is limited and space is limited, yes, there’ll be some solutions where we will need seawalls just because we can’t create a beach there or because we’re limited by what already exists.”
In recent years studies by the IDB and Sustainable Nassau have explored ways to address the problem under the National Development plan. Palacious says the next step is assessments and laying out the plan that will be used.
“It’s an exercise that can be done, I would say relatively quickly and relatively effectively and then be implemented, and a number of studies have been done around it,” he said.
Opting exclusively for greener solutions, Bahamas Reef Environment Educational Foundation’s Executive Director, Casurina McKinney-Lambert says traditional seawalls cause more damage than protection.
“Construction, including things like seawalls and groins, can actually contribute to the erosion of the shoreline and cause more damage to the beaches and the houses that they’re intending to protect,” she said
“So they actually deflect the wave energy and can cause increased erosion […] in particular to the buildings or to the areas adjacent to where the seawall is put in place.”
McKinney-Lambert says BREEF encourages the use of natural breakwaters like coral reefs and mangroves to break wave energy, especially in a geological time of rising sea levels.
“The ocean is actually getting higher. So because of this, it’s really important that we build our structures, our buildings, our houses, our hotels, our roads, and our other infrastructure further inland to take into account the fact that the sea levels are rising and that we’re faced with increasingly strong storms and hurricanes as a result of climate change,” she said.
Senior Scientist and Policy Analyst at The Bahamas National Trust, Dr. Ancilleno Davis says that the solution is not just simply green or grey. He noted that seawalls do not protect against flooding but rather limit storm surge energy.
He added that both options can be used depending on the area.
“It depends on what level of wave energy you’re fighting against, what type of coastline you have, and whether or not you want to protect the natural coastline or if you’re more interested in protecting infrastructure.”
The senior scientist explained, however, that in the case of most family islands where there hasn’t been much development, reinforcing natural infrastructure is ideal.
“I would like to recommend that the government looks at more green infrastructure for our family islands that are not impacted yet might development and have not had those things removed. So as we develop other family islands, we should look more at a mixture of green and green infrastructure” he said.
In years gone by the construction of seawalls was frowned upon by members of the environmental community and while Davis agreed that it more or less was warranted, new developments in seawall technology have been crafted to limit the amount of potential damage to natural coastlines.
Davis said: “Now that a lot of sea walls aren’t just a flat space where that wave would hit it, and slosh up over it; but they actually have a curved back; so that it will curve that energy back into the ocean.
“And you can look around in Providence, and there are certain areas when the waves hit and it splashes into the road or it washes the sand into the street and you wonder what exactly is that seawall doing?
“But again, there are new technologies out, new ways to build seawalls that I think we can implement around New Providence to make it more resilient to climate change and the impacts of these storms that we can expect in the future,” Davis said.
