Glenn McGillivray is the managing director at the Institute for Catastrophic Loss Reduction.
Just one year after Hurricanes Harvey, Irma and Maria (also known as HIM) wreaked havoc across parts of the Caribbean and the United States causing around US$92-billion in insured damage (not including billions in federal flood insurance claims), another disconcerting scene is playing out in the North Atlantic Basin with a major hurricane thumping the southeastern U.S. coast and Tropical Storms Helene and Joyce churning out in the Atlantic. A fourth, Tropical Storm Isaac, luckily fizzled out in the Caribbean Sea on Friday.
At one point Hurricane Florence was larger than the state of North Carolina, more than 139,000 square kilometres in area.
Despite what the general public says and feels about the accuracy of weather forecasts, the storm, it appears, is doing almost exactly what meteorologists said it would do.
With amazing accuracy, the storm made landfall just three kilometres from where the models projected it would. What’s more, the storm crawled to a near stop just as forecasters anticipated, at one point moving slower than the average person can walk. Storm surge projections and rainfall estimates are also proving to be incredibly accurate.
So what appears to be a win for meteorologists will go down as a major loss for the 10 million people estimated to be at direct risk from the storm.
One modelling firm has estimated that insured damage from Florence will fall somewhere in the US$3-billion to US$5-billion range, not including National Flood Insurance Program claims.
There are still a few things we don’t know about Florence, but one thing is clear: The amount of water that will be driven by this storm will be historic for the area, as meteorologists project that the event will unload anywhere from 10 trillion to 17 trillion gallons of rainwater in just a few days. Indeed, invoking the huge storm that struck Houston in late August, 2017, USA Today called Florence “the Harvey of the East Coast.”
The parallels between Florence and Harvey are troubling.
It is estimated that the days-long rainfall associated with Harvey dumped 33 trillion gallons of water over Texas and the southern United States. It is considered to be a rare one-in-1,000-year event, giving it an annual probability of occurring of just .1 per cent (stormwater infrastructure in much of Canada is designed for a one-in-100-year event, having a 1-per-cent probability of occurring in a given year). Some parts of the Carolinas have already been hit by one-in-1,000-year rainfalls from Florence.
Problems in Houston that became crystal clear as a result of Harvey had a great deal to do with runaway urban development, including the paving over of green space and wetlands, which are instrumental in managing excessive stormwater. Essentially, the city had no zoning laws to direct or control sprawl, so property developers ran amok. Incredibly, at least one suburb consisting of 721 homes was built within the levees of a reservoir.
Whether similar issues exist in those parts of the Carolinas currently being inundated by Florence is largely unclear (though one reporter noted that North Carolina had about 11 million acres of coastal wetlands before colonization and has about 5.7 million acres now, a lost of close to half). Once again, people have chosen some terrible places in which to place communities, such as on coastlines, peninsulas, in lowlands, beside rivers and such.
Where we have chosen to place assets is one of the main drivers of disaster losses.
Contrary to popular belief, the disaster isn’t the event (i.e. the wildfire, the earthquake or the hurricane). These are called hazards. The disaster only comes when the hazard exploits vulnerabilities in the built environment, such as where we build and how we build.
One thing planners have learned is that when large portions of communities are severely damaged or destroyed as a result of war or calamity, once in multigenerational opportunities are presented to rethink what we have built and where we have built it and to correct old mistakes.
But we seldom take these opportunities to heart as everyone seems to just want to put everything back where and how it was. Indeed, a U.S. senator who mused aloud about whether New Orleans should be rebuilt after 2005’s Hurricane Katrina was nearly run out of town.
As Earth’s atmosphere continues to warm, there are places that will see more water, from heavy rainfall, storm surge and sea-level rise.
Make no mistake: This is not just a coastal problem, as many residents of Toronto found out when heavy rains inundated parts of the city in August.
A big lesson to come out of Hurricane Harvey, and likely out of Florence, is the need to learn to live with water, including the need to retreat entirely from some areas when it is prudent.
We must, as we will have little choice.
What we are experiencing now is just climate change on training wheels.
We ain’t seen nothin’ yet.