Driving through flood water
Driving through flood water is a daunting and dangerous task, in fact a third of flood related deaths happen in vehicles. Whether you’re facing heavy rain, flash floods, or just a waterlogged road, knowing how to navigate these situations is crucial for your safety and the safety of others on the road. In this blog, we’ll provide essential tips for safely driving through floodwater and what to do if you find yourself in this challenging situation.
Is it safe to drive through flood water?
The first step when encountering floodwater is to assess the situation. Is the water shallow or deep? Is it moving or stagnant? Are there any obstacles or debris in the water? Before attempting to drive through it, take a moment to carefully evaluate the conditions. If the water is too deep, swift-moving, or you cannot see the road beneath it, it’s best to turn around and find an alternative route.
Your vehicles fording depth
Understanding your vehicle’s capabilities is essential. Different vehicles have different levels of tolerance for water. Trucks and SUVs with high ground clearance generally handle water better than smaller cars. Know your vehicle’s fording depth, which is the depth of water it can pass through without taking on water. It’s measured as the distance between the point touched by the car’s tyres and the engine’s air intake system.
This information can usually be found in your owner’s manual.
How to drive through flood water
As you enter the floodwater, drive slowly and steadily. Maintain a constant, controlled speed, typically around 3-5 mph. Avoid sudden acceleration or braking, as this can cause your tyres to lose traction. Keep a consistent, slow pace to minimize the chances of hydroplaning or stalling.
Whenever possible, stay in the centre of the road. This is usually where the road is slightly higher, and the water is typically shallower. Avoid driving near the edges, as water is often deeper and more unpredictable there.
Just as you would in dry conditions, keep a safe following distance from the vehicle in front of you. In floodwater, it’s challenging to gauge depth and potential obstacles, so having a buffer between your vehicle and the one ahead provides an extra margin of safety.
- Don’t drive into flood water that’s moving or more than 10cm (4 inches) deep. Let approaching cars pass first.
- Drive slowly and steadily so you don’t make a bow wave.
- Test your brakes as soon as you can afterwards.
What to do after driving through floodwater
Once you’ve successfully navigated the floodwater, lightly tap your brakes to dry them out. This helps restore your braking efficiency, which may have been reduced by water exposure.
Even if it seems to be running fine after driving through floodwater, it’s a good idea to have a mechanic inspect it for any potential damage. Water can affect various parts of your vehicle, and problems may not be immediately apparent.
The dangers of driving in flood water
- A third (32%) of flood-related deaths are in vehicles.
- If the speed of the flood water doubles, the force it exerts on you or your car goes up four times.
- Just 60cm of standing water will float your car.
- Just 30cm of flowing water could be enough to move your car.
- A mere egg cupful of water could be enough to wreck an engine.
Can driving through flood water damage my car?
Driving through floodwater can be one of the riskiest decisions you can make as a driver. Besides the immediate danger to your safety, it can also have severe consequences for your vehicle. Let’s look at the hidden perils of driving through floodwater and how it can cause extensive damage to your car.
Engine damage
One of the most significant risks when driving through floodwater is the potential for engine damage. Your car’s engine depends on clean air and a well-functioning exhaust system to operate efficiently. When you drive through floodwater, your engine can ingest water, which is detrimental. Water can’t be compressed like air, and if it gets into the engine, it can lead to bent connecting rods, a cracked engine block, or a hydro-locked engine. The repair costs can be astronomical.
Electrical systems
Modern vehicles rely heavily on electrical systems to function properly. Driving through floodwater can cause significant damage to these systems. Water can infiltrate the wiring, circuitry, and sensors, causing electrical shorts and malfunctions. If your vehicle’s computer systems get damaged, you might experience issues with everything from power windows to engine control units. Replacing or repairing these components can be costly.
Transmission problems
Your car’s transmission is another essential component that is highly susceptible to flood damage. Water can infiltrate the transmission system, contaminating the transmission fluid and leading to corrosion and eventual failure. A transmission replacement can be an incredibly expensive repair, making this yet another reason to avoid driving through floodwater.
Brake system damage
A functional brake system is critical for your safety on the road. When you drive through floodwater, water can penetrate the brake system, contaminating the brake fluid. This can result in reduced braking performance, which is a severe safety concern. It may also lead to corrosion and deterioration of brake components, requiring expensive repairs or replacements.
Suspension and exhaust system damage
Driving through floodwater can introduce grit and debris into your car’s suspension and exhaust systems. This can lead to corrosion and increased wear and tear on these components. As a result, you may experience a bumpy, uncomfortable ride and reduced fuel efficiency. Replacement or repairs to the suspension or exhaust systems can also be costly.
Vehicle interior damage
Floodwater doesn’t discriminate, and it can enter your car’s interior, damaging the carpet, upholstery, and electronics. Mold and mildew growth are also common after a flood, which can lead to persistent odors and health issues for passengers.
FAQ's about driving through floodwater
If you drive an electric or hybrid vehicle you should follow the same precautions as ICE vehicle drivers when confronted with flood water. However, electric cars, due to their electrical components, are particularly vulnerable to damage when exposed to water, so extra caution should be taken.
Yes.
Fording depth is also referred to as wading depth. It is the distance between the point that water touches your tyres to the air intake.
If you suspect that water has infiltrated your engine, be alert for several critical signs, including:
- The ignition key producing a rapid cranking noise or whirring sound.
- An unusually intense fuel odour, particularly in the vicinity of the exhaust pipe.
- Your vehicle either refusing to start, or initiating briefly and then promptly stalling.
If your car is covered by a comprehensive insurance policy, you may be eligible to make a claim for flood-related damage to your vehicle, provided you’ve diligently protected your car. However, if you choose to drive your car into a flood without taking necessary precautions, your insurance may not cover any resulting damage.