How Floods Affect the Economy and You

Why Floods Are a More Dangerous Threat Than Terrorism

The economic impact of floods in the U.S. One inch of water can cause $25,000 of damage to a home Since 1980, the U.S. suffered over $260 billion in flood-related damages Much of the cost of flooding is passed on to taxpayers Floods increase food prices and strip farmland of needed nutrients

Image by Julie Bang © The Balance 2020

Floods are the most common natural disaster in the United States. Their damage is so extensive that they are responsible for 90% of all damage related to U.S. natural disasters.

According to the National Weather Service, floods kill 95 people a year on average. Flooding killed 93 Americans in 2019 alone. Let's look at what causes these dangerous weather events—and what can be done.

What Causes Floods?

Global warming is causing more floods. As temperatures rise, the air holds more moisture. Rainfall becomes less frequent, creating droughts. At some point, the skies release their moisture in a torrential downpour. That creates floods. Instead of soaking into the ground, the water runs on hard-packed earth that has dried out during the drought.

Climate change may also cause floods by shifting the pattern of the jet stream. The Arctic is warming faster than the temperate zones, which can change the air pressure and turn the jet stream. When it plunges south, it can pick up tropical moisture from the Gulf of Mexico and dump it on the East Coast.

Higher temperatures also mean less snow and more rain. One-sixth of the world's population relies on snowmelt for its water supply. They expect slowly melting snow to supply water at a steady pace. Instead, they will receive buckets they aren't prepared to store.

Along the shoreline, rising sea levels are making floods worse. Consider these facts affecting Florida:

  • In Miami, the ocean floods the streets during high tide. To cope, the City of Miami Beach launched a five-year, $600 million public works program. 
  • Harvard researchers found that home prices in lower-lying areas are rising more slowly than those in the rest of Florida.
  • A study using Zillow found that properties at risk of rising sea levels sell at a 7% discount to comparable properties. They include Key Biscayne, Sunny Islands, and Golden Beach as well as Miami Beach.
  • By 2030, Miami Beach homes could pay $17 million in higher property taxes due to flooding, the Miami Herald reported. At the same time, nearby properties that are at higher elevations are experiencing rising prices.

Extreme weather will increase flooding. Over the next few decades, river floods will threaten tens of millions of residents. A 2018 study found that over half the United States will need to double existing flood protections.

Major Flood Events in Recent Years

The past decade has seen record flooding across the United States. Here are just a few examples.

2019 Floods

Record snow and rain flooded several Midwest states in March 2019. Three people died and thousands had to evacuate. Damage estimates were $10.9 billion. At least 13 Missouri counties were declared major disaster areas. The Nebraska Department of Agriculture said flooding could cost the state $440 million in crop damage and $400 million in cattle losses.

The National Oceanic and Atmospheric Administration warned that 25 states along the Mississippi faced flooding through May 2019. The heaviest flooding occurred along the Mississippi basin in North Dakota, Minnesota, Nebraska, Iowa, and Missouri. Ultimately, these states' levee systems could not withstand crest levels that reached as high as 25 feet.

In 2017, the American Society of Civil Engineers gave the U.S. levee system a D grade, estimating that it would cost $80 billion to bring the system up to standards.

2018 Floods

In 2018, floods killed 80 people, slightly fewer than the 116 people in 2017. In July 2018, the National Weather Service announced "dangerous, life-threatening floods" from Pennsylvania to North Carolina, affecting millions of people. Area storms delayed flights in New York and Philadelphia.

Record Mississippi River Floods

The 2011 Mississippi River flood was historic. The river experienced historical crests, while dams and levees were breached. Heavy snowmelts, historic rainfalls, and April's tornadoes triggered flooding from the Ohio River, as well. Fear of flooding oil refineries spiked gas prices. That fear subsided with the opening of the spillways, and gas prices dropped.

The Army Corps of Engineers estimated it cost $2 billion to repair the damage caused by the flood. The Mississippi River runs past farmlands and cities in six states. Damage from the flood made these communities more vulnerable to future floods. The Corps received $802 million from Congress to identify and repair the weakest areas.

The 1993 Mississippi flood was the costliest U.S. flood of the 20th century. It caused $15 billion in damages. The National Oceanic and Atmospheric Administration reported that more than 20 million acres in nine states were flooded. Approximately 54,000 people were evacuated, while 50,000 homes were destroyed or damaged. The flood swamped 75 towns, some of which were never rebuilt.

The 1927 Mississippi River flood was the most destructive in U.S. history. More than 700,000 people were left homeless, while 250 died from floods that covered 1 million acres with 10 feet of water in 10 days. More than 200,000 African Americans were forced to live in refugee camps for months. This triggered a mass migration of African Americans to northern cities. As a result of the flood, the U.S. government created a comprehensive levee system to manage the Mississippi.

Economic Impact of Flooding

Floods are very damaging to homes. For example, just one inch of water can cause $25,000 of damage to your home, according to Floodsmart. Homeowners' insurance doesn't cover floods. Homeowners in high-risk flood areas are required to purchase flood insurance.

Many homes in recent floods did not have flood insurance because they were outside the 100-year floodplain, which identifies land that would be underwater in a 100-year storm. For example, 75% of the 204,000 homes damaged in Hurricane Harvey were outside the floodplain.

Between 1980 and 2013, the United States suffered more than $260 billion in flood-related damages. There are 1,400 chemical sites located in America's high-risk flood zones.

Because it can damage crops or delay planting, flooding also causes food prices to spike, depending on how fast the floodwaters recede. This can have severe economic consequences for both farmers and consumers.

Because of the far-reaching effects of flooding, the U.S. Congress established the National Flood Insurance Program in 1968. The last time it was broadened was 2004. By 2018, it had accumulated $20.5 billion in debt. The added cost increased the national deficit and debt. As a result, much of the cost of flooding is passed on to taxpayers.

Flooding Solutions

There are ways to reduce the damage from flooding. The federal government offers grants to help homeowners elevate their houses. It recommends they move their house to higher ground or put their house on flood-resistant higher foundations. Homeowners must also install flood vents.

In 2015, President Barack Obama signed an executive order requiring planners of federally funded buildings, roads, and other infrastructure to account for the impact of possible flooding from rising sea levels or more extreme precipitation. President Trump rescinded those rules in 2017, but President Biden reinstated them during his first days in office in 2021.

Mitigation strategies that help people cope with floods will only go so far. By 2100, more than half of the communities along the Eastern Seaboard and Gulf Coast will be “chronically inundated.” They will see their area flooded at least twice a month on average, according to the Union of Concerned Scientists.

To prevent that, global warming must be reversed. To accomplish this, humanity must stop adding greenhouse gases to the atmosphere. That means:

  1. Eliminating coal as a fuel for electric generation by 2040. 
  2. Using solar and wind power for electricity generation.
  3. Capturing the carbon dioxide emitted by biofuel plants and storing it underground.

To reverse rising temperatures, humanity must also remove 30 years’ worth of carbon dioxide from the atmosphere by 2100. That would require geoengineering on a grand scale. Carbon sequestration captures and stores existing carbon dioxide from the atmosphere. The best way to do that is to plant massive quantities of trees. For perspective, the Associated Press reported that the world is emitting about 40 billion tons of carbon dioxide into the atmosphere every year with the Amazon rainforest absorbing only 2 billion tons of it.