Despite being a Category 4 hurricane at landfall, we don’t remember Hurricane Harvey for its winds. Rather, we remember Harvey as a rain producer of biblical proportions. While the flood event took center stage and has prompted discussion around flood insurance and mitigation ever since, there are lots of other lessons to be learned from the catastrophic storm.
One positive to come out of Hurricane Harvey and Hurricane Irma (another Category 4 storm that struck a week after Harvey) was that both storms showed how effective strong wind-resilient building codes are in reducing wind-related damages from events like hurricanes, tornadoes and extratropical windstorms, according to Mark Bove, senior research meteorologist at Munich Reinsurance America.
“The magnitude of Harvey’s flooding in southeastern Texas has slightly overshadowed the message about strong building codes,” Bove said. “What we saw was that the more modern construction in Texas and the municipalities in Texas that require stricter building codes all performed much better overall [with regards to resilience against Harvey]. These building codes, especially as they’re implemented on a widespread scale, really show that we can build to withstand all but the worst of these storms and we can reduce the risk to life and damage to properties.”
Another lesson to take from Harvey is that everyone is in a flood zone. As Bove noted, if you get 60-inches of rain within five days, pretty much any area is going to flood, even if it has the best mitigation in place. Flash-flooding caused by an overwhelming amount of rainfall in a short period of time often catches people off-guard, especially those who think flooding only really occurs in river or coastal areas.
“An issue that potentially exacerbates this flood risk perception problem is that in the US you’re only required to purchase flood insurance when you have a mortgage from the bank and your property is located in a flood hazard area,” Bove added. “Those with properties located outside of the flood zones sometimes hold the perception that they’re at a much lower risk and therefore can potentially forego buying flood insurance because the banks aren’t mandating the purchase. A lot of people in Houston now realize that’s not necessarily the case.”
A third issue highlighted by Harvey is that towns like Houston and many other metropolitan areas in the US have grown rapidly over the past 30 or 40 years, and as part of that rapid expansion, they have paved over a lot of local land and therefore changed the flow of water in their respective areas.
“Essentially, we’re giving heavy rainfall less places to go so it ends up flooding our built-up environment, which is exacerbating damages,” Bove told Insurance Business. “Though record-setting, the flooding in Houston was not necessarily unprecedented. We’ve seen many flash flooding events that have cause significant damages in Houston, with Harvey now being the extreme case. A good proportion of the damage is likely due to the volume of local rivers combined with the human environment and construction, which can no longer handle certain rainfalls of a given magnitude.”
Are you interested in learning more about flood risk? Join Insurance Business at the Flood Risk Summit in Miami on November 29 as leading experts discuss flood insurance issues.