This Year Has Already Been The Deadliest For Flooding Since 2017 and Another Flooding Threat Looms

 Linda Lam

Published: September 13, 2021

This year is already the deadliest for flooding since 2017, and with another tropical cyclone expected to dump heavy rainfall along parts of the Gulf Coast this week fatalities could rise.

Flooding has killed 116 people United States so far in 2021, making it the first year since 2017 flooding fatalities topped 100.

In the past 10 years, flooding deaths have ranged from a low of 29 in 2012 to 189 and 180 in 2015 and 2017, respectively.

Hurricane Harvey was a major contributor to flood deaths in 2017, when heavy rainfall killed 70 people in Texas. In 2015, extreme rainfall led to at least 40 deaths in May in the Southern Plains, and then in October, 16 people were killed by flooding in South Carolina due to the combination of an upper low and tropical moisture from Hurricane Joaquin.

The relatively low toll in 2012 was partly due to the U.S. having an expansive drought and its 15th driest year on record.

There have been a couple of notable flood events this year.

Earlier this month, the remnants of Ida combined with a front that resulted in deadly and destructive flooding in the Northeast. At least a dozen people died in flooding in New York City. Deaths were also reported in New Jersey, Pennsylvania and Connecticut.

It doesn't take a tropical system to produce life-threatening flooding. More than 20 people died in Tennessee in August from catastrophic flooding when it rained more than 15 inches in some spots in just 24 hours.

The Southwest has also experienced deadly flash flooding. Although rainfall was welcomed after the past two generally dry monsoon seasons, the heavy rain that quickly fell at times resulted in flooding that killed more than a dozen people this year.

What To Know About Flooding

An average of 85 people are killed by flooding annually in the United States, according to NOAA (1991-2020). That's more than the average number of deaths per year from tornadoes (69) and hurricanes (46).

Only heat claims more lives in an average year than flooding.

The deadliest time of year for flooding typically is late spring through the summer when humid air is more abundant. Thunderstorms can drop multi-inch totals quickly, especially when they persist over one area.

Tropical depressions, tropical storms and hurricanes also add to flood dangers. This week, Tropical Storm Nicholas will bring the Gulf Coast and parts of the South ample rainfall and potentially life-threatening flooding.

(MORE: Why Houston Is Likely America's Rainfall Flooding Capital)

Turn Around, Don't Drown

Many flooding deaths could have been avoided. That's because 58% of the 997 fatalities blamed on flooding from 2011 to 2020 happened in vehicles, according to the National Weather Service. More than a third of the flooding deaths so far in 2021 have occurred this way.

So do not drive into floodwaters. Turn around and find another route or delay a trip. It's hard to judge the depth of floodwater, particularly at night. Sometimes the bridge or road masked by floodwaters may have been undermined or completely washed out.

It is also important to keep in mind that conditions can change quickly over a short distance.

Here are some additional facts from FEMA to consider:

- Six inches of water will reach the bottom of most passenger cars, causing loss of control and potential stalling.

- One foot of water will float many vehicles.

- Two feet of rushing water will carry away most vehicles, including SUVs and pickups.

Once a vehicle is floating, the floodwaters become a steering wheel. If that water is moving, a vehicle could be swept away, tipped on its side or flipped. Rising water can enter a vehicle in minutes, even seconds.

The bottom line is: Turn around, don't drown.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.