Managing Inevitable, Deadly Flash Floods

Managing Inevitable, Deadly Flash Floods

Thirty-seven people are dead following flash floods that rocked Kentucky and St. Louis last week. Residents are still recovering from the twin catastrophes, prompted by rain events described as “one-in-a-thousand.” And these are only the latest disasters in a worsening pattern of summer flash floods that are pummeling the Appalachia and Midwest regions.

Meteorologists say climate change is the catalyst for such devastation. They note that one effect of the atmosphere warming is that it holds more water, triggering longer, heavier, and more sudden rainstorms.

In other places, a warming atmosphere can also have the opposite effect. In California, for example, extreme heat and drought produced a wildfire so large and hot that it’s generating its own cloud formations and weather.

PBS: Extreme conditions in California and Kentucky force thousands from their homes, August 2, 2022.

Museum of Science, Boston: Sensing Our Climate | Extreme Precipitation, March 3, 2022.

Stanford Woods Institute for the Environment: AI for climate change | Stanford researchers predict extreme precipitation with machine learning, August 10, 2021.

Why This Matters

Two words: prevention and mitigation. Current flood prevention systems are not equipped to deal with the amount of rain brought by one-in-a-thousand-year storms. Under normal circumstances, rainwater is absorbed by the soil and fed to rivers that channel it away. Excess rainwater is taken care of by storm drains and culverts -- systems typically able to prevent flooding. But in extraordinary conditions can become overwhelmed by too much water coming down too fast.

The suddenness of flash flooding maximizes its devastation. Residents are given little to no time to prepare or evacuate their homes or businesses, and these events can be particularly deadly. At least 100 homes were damaged by floods last month in Virginia with many structures torn from their foundations.

CNN: Kentucky flood survivor describes being in house as it was removed from foundation, August 1, 2022.

PBS: Kentucky Gov. Andy Beshear on the aftermath of devastating floods, August 2, 2022.

Guardian: Climate change is making floods worse - here's how, October 19, 2021.

As they become more common, additional flood prevention measures may be necessary to keep at-risk regions safe. The White House announced Monday that it would put $1 billion dollars towards a state disaster relief fund to help communities prevent and recover from extreme weather disasters like the flooding seen in Kentucky.

“We know that the impacts of the climate crisis are here, and that we must invest in building resilience to protect our communities, infrastructure and economy,” said the White House in a statement.

MSNBC: Climate Expert On Extreme Heat: ‘We’re Not Going To Be Able To Find Solutions,’ July 19, 2022.

Grantham Imperial: Dr Friederike Otto speaks to BBC World News about the heatwaves, 18 July 2022, July 19, 2022.

ABC: Rainfall from climate change could affect economic growth | Study, January 12, 2022.

Beyond the US

The fallout from heavy rains is being felt beyond the US. In Iran, 80 are dead and 30 missing after last month’s torrential rains gave way to a series of floods and mudslides. The disaster will cost the country’s agricultural sector the equivalent of $200 million and came amid a cycle of extreme wet and dry periods, a combination that increases the risk of severe floods. This is not the first time Iran has experienced an extreme cycle as such. In 2019, 70 people were killed by flooding.
Meanwhile, Bangladesh, India and Pakistan are currently facing the worst floods in over a century and a much heavier and earlier monsoon season. In Bangladesh, ranked the 7th-most vulnerable country to climate change, flooding has impacted 7.2 million and, killed over 100 people while ravaging 375,000 hectares of critical cropland. More than 1.2 million people are now in need of immediate humanitarian aid, yet wealthy countries that contribute to the UN Central Emergency Response Fund are currently only prepared to provide 20% of what’s needed.

AP: Rain triggers deadly flash floods in Iran, Jul 29, 2022.

DW: Floods, drought and the consequences of extreme weather, July 16, 2022.