Louisiana recovers from extreme floods


Pervasive flooding caused by extensive rain in South Louisiana in the last two weeks has led to major property damage to approximately 60,000 homes and more than 7,364 businesses, as well as 13 deaths, according to AIR Worldwide.

Flood water levels are now falling and many people have been able to return to their homes and businesses, despite a state of emergency scheduled to remain until September 10.

Over the period of August 8 to 15, a slow-moving storm system affected south central Louisiana, with some regions receiving as much as 15 to 30 inches of rainfall of a two-day period.

“As a result of record breaking rainfall [over] a vast swath of more than 50 miles by 100 miles, covering Baton Rouge, Lafayette, adjourning suburbs, historic crests at 12 of the 33 real-time river gauging stations of the USGS in Louisiana were surpassed,” said Hemant Chowdhary, principal scientist at AIR Worldwide.

“The very heavy rainfall in the watersheds of Amite, Comite, Tickfaw, and Tangipahoa rivers resulted in flood levels up to six feet over their previous historic records.

“The historic flooding in and around Baton Rouge and other areas is a combination of several factors including riverine (on-floodplain) flooding, backwater in tributaries due to high flood stages in main rivers, and significant local flash flooding (off-floodplain) caused by intense rainfall, flatter terrain, and limited drainage capacity that was further exacerbated by backwater effects. Many of the areas that flooded were outside the 100-year floodplain and were not considered at high risk.”

AIR said that US residential flood insurance is typically offered to homeowners only through the National Flood Insurance Programme, with the Federal Emergency Management Agency estimating that only 42 percent of homes in high-risk areas of Louisiana have flood insurance.

“The experience of Hurricane Katrina revealed that commercial insurers did not always have good information about their exposure to flood and, indeed, estimates of total industrywide insured flood values remain hard to obtain,” the catastrophe modelling firm said.

The impact to the insurance industry will become clearer as the floodwaters recede and assessments can be conducted, as flood damage and associated losses can result from time-related elements such as the length of exposure to floodwater, AIR suggested.

AIR Worldwide, North America, Flood risk, Insurance, Risk management, Bermuda, Hemant Chowdhary, Catastrophe

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