Floods were responsible for an average of 110 annual fatalities in the U.S. over the last decade, and many of the people who tragically lost their lives tried to drive through fast-moving waters.
So, what should you do when there is a flashflood while driving?
Organizations such as the National Weather Service and Centers for Disease Control and Prevention (CDC) have issued guidance regarding the dangers posed by floodwaters. By understanding the risks associated with driving in flash flood conditions and dealing with contaminated waters, everyday people are better equipped to avoid illness, injury, and unnecessary drowning fatalities.
What is Considered a Flash Flood?
Flash floods are waters that overrun normal riverbanks and lakes, or that spill across roadways and residential areas. They usually develop within a six-hour period, driven by heavy rains, hurricanes, tornadoes, dam ruptures, or other extreme conditions. In some cases, floods can happen within minutes, leaving people at risk.
Flash floods quickly erode tree roots, shift boulders, and carry away cars, trucks, and SUVs with ease. It’s not unusual for floods to suddenly pick up momentum and rise from a knee-deep measure to upwards of 30 feet or more. Unpredictable and laced with hidden hazards, flash floods are known to also trigger deadly mudslides.
Coupled with hazardous chemicals and sharp objects, these catastrophic weather-related events are also a danger to first responders tasked with rescuing trapped motorists, as well as decontamination crews who cleanup in the aftermath of a flood.
What Makes Floodwater so Dangerous?
One of the primary reasons motorists are swept up in floodwaters stems from misjudging their deadly force. Drivers and pedestrians may see only one or two feet of what appears to be relatively slow-moving water. Even those who see flooding depictions on the evening news or social media notice the conditions look less aggressive than river rapids. Despite their appearance, floodwaters exert a unique force on automobiles.
According to literature produced by the National Weather Service, flood water weighs 62.4 pounds per cubic foot and typically travels at 6 to 12 mph. Should a driver try to traverse two feet of water, the engine’s air intake sucks in water and the vehicle stalls. At this point, each foot of rising water generates 500 pounds of lateral force that pushes against the vehicle.
But the point of no return occurs once the water reaches the vehicle’s side panels. For each foot of water that climbs above the floor, it produces 1,500 pounds of buoyancy force. That means each foot reduces the vehicle’s weight by 1,500 pounds. Compact cars average 2,500 pounds and SUVs start at about 3,500 pounds. Based on the math, it’s easy to see how seemingly steady water can topple a vehicle and drown the occupants.
Floodwater Contaminants and Risk Factors
It’s essential for communities impacted by flooding to follow emergency broadcast system warnings and weather alerts. Fast-moving storms can produce flash floods with enough force to knock over an adult standing in only six inches of water.
Along with their deceptive power, the objects moving beneath the muddy surface can cause blunt force trauma or cause a gaping wound. Furthermore, raging flash floods accompanied by intense storms naturally attract lightning strikes, making them an electrical danger.
Nearly every flash flood will pick up wide-reaching contaminants that can taint local drinking water. Contact with floodwaters can also lead to severe or deadly infections and illnesses. The CDC warns the following are common dangers associated with floodwater contact.
- Human excrement and household waste
- Pet and livestock feces, along with other agricultural waste
- Fertilizer and pesticides
- Residential cleaning agents and chemicals
- Diesel fuel, gasoline, kerosene, and other combustibles
- Arsenic, chromium, and mercury found in coal ash
- Displaced snakes, rodents, insects, and aggressive animals
- Broken glass and other sharp objects
- Lumber, household products, and machinery
Motorists forced to abandon stalled vehicles and come in contact with contaminated floodwaters are at heightened risk of illness and infection. The same holds true for rescue workers and cleanup crews. That’s why wearing personal protective equipment (PPE) and disposable clothing are a standard safety practice.
CDC Health and Safety Recommendations
The CDC urges all rescue workers to wear PPE while dealing with flash floods. Exposure to common pollutants can result in the following.
- Infected wounds and abrasions
- Skin rashes
- Hepatitis
- Legionnaires’ Disease
- E. Coli
- Salmonella
- Leptospirosis
- Tetanus
- Cholera
- Typhoid fever
People living in these disaster zones are also likely to see a spike in mosquito swarms. Because biting insects are spawned in contaminated waters, they are known to carry diseases such as Zika, Dengue, and Chikungunya, among others. The CDC recommends avoiding exposure to floodwaters, treating cuts, scratches, and wounds immediately, and frequent hand sanitizing.
What is the National Weather Service’s ‘Turn Around Don’t Drown’ campaign?
Nearly 50 percent of all flooding deaths are related to driving and the majority are male. People who attempt to cross rising waters also put first responders and rescue workers at risk of injury, illness, and death. Those are a few reasons why the National Weather Service launched its Turn Around Don’t Drown campaign.
This program to increase awareness about the dangers of driving through flash floods was launched by Texas meteorologist Hector Guerrero in 2003. Working with colleagues from the National Weather Service and other stakeholders, the program was designed to help educate people in flood-prone areas.
A press release issued by the Federal Emergency Management Agency (FEMA) noted that motorists commonly “underestimate” floodwater force. These are basic tenets of the Turn Around Don’t Drown public service campaign.
- Monitor the weather platforms, radio, and local news outlets for vital information when storms are expected in your area.
- Get to high ground in the event of torrential downpours in areas likely to flood.
- Avoid places within the flood plain, low ground, and never take refuge in ditches.
- Evacuate places along rivers, and streams, and do not attempt to cross moving water.
- Do not drive during severe weather storms and flooding if possible.
- Keep in mind that roads in flooded areas may be washed away and contain deep holes.
- Do not park your vehicle along waterways, ditches, or lowlands when conditions appear threatening.
- Homeowners in flood plains are advised to cut their power when water begins to rise.
- Do not attempt to walk through water six inches and deeper.
- When evacuating on foot, use a stick to check ground conditions.
Turn Around Don’t Drown guidelines also advise motorists who get stuck in a flood to quickly unbuckle their seat belts, abandon the vehicle, and move to higher ground if safely possible. It may be wise to also roll down the windows before the automobile loses power. The force of water against doors can make them difficult, if not impossible, to open. And, half of all flood-related drownings occur when people become trapped inside their vehicles.
The key to flood safety is to never enter even seemingly low floodwaters. It only takes six inches of water to reach the underside of a passenger vehicle. This creates hazardous driving conditions resulting in car wrecks and engine stalls. One foot of water has the capacity to float a compact car and just two feet can carry off many SUVs and pick-up trucks.
Flash Floods Continue to Pose Clear and Present Danger
After launching Turn Around Don’t Drown, flood-related deaths dipped from 85 in 2003 to 43 by 2005. Whether a matter of awareness or other factors, the U.S. continues to sustain a significant number of flooding events and accompanying fatalities.
The highest number of deaths (176) since the Turn Around Don’t Drown rollout came in 2015. There were only nine flood disaster declarations that year compared to 25 in 2019. Deaths also spiked in 2021 despite only a low number of flood disaster declarations.
The uneven data may indicate heightened awareness, and more public service announcements are needed to educate people about the risks of floods. It’s also critical for rescue workers and post-flood decontamination teams to have full access to PPE and disposable protective clothing. International Enviroguard manufactures and distributes a complete line of personal protective clothing that exceeds industry standards for hurricane and floodwater response and/or cleanup teams.