What To Do If You Get Caught In A Flash Flood

If you find yourself caught in your car during heavy rain or flash flooding, there are a number of things you should do to keep yourself, your passengers and your fellow road users safe. Not only that, but regular car maintenance can reduce the risk of weather-related incidents – including checking the brakes and tyres regularly.

Here, we offer expert tips on how to drive in wet weather and floods, as well as guidance on keeping your car well maintained no matter what the weather throws your way.

Driving Through Heavy Rain and Standing Water

Driving in wet conditions can be dangerous, even if there’s just a few millimetres of standing water on the road. During a heavy downpour, visibility can be extremely limited, and puddles and surface water can easily cause aquaplaning, whereby your car loses traction and steering response.

When driving in heavy rain and standing water, remember to do the following:

  • Use your headlights: Heavy rain will mean that visibility is extremely reduced, so you should switch on your headlights when you can’t see for more than 100m. In some cases, it might be worth switching on your front and rear fog light, so long as you remember to switch them off when visibility improves.
  • Double the distance between yourself and the car in the front: When it’s pouring down and there’s standing water on the road, stopping distances are almost doubled – so always leave twice the distance between you and the car in front.
  • Ease off gradually if you start aquaplaning: If your car starts aquaplaning as a result of driving through standing water, your gut reaction may be to stamp on the brakes – but this could result in an uncontrolled skid. Instead, ease off the accelerator and start to slow down gradually, keeping both hands on the wheel and making light adjustments to the steering.
  • Don’t speed through standing water and puddles: If there’s surface water on the road, there’ll be a lot of spray around that can affect other road users and pedestrians. If possible, avoid massive puddles by the kerbside and don’t speed through standing water as this will throw up water which will soak pedestrians and cyclists. If the police think you did so deliberately, they could give you a hefty fine and add 3-9 points on your licence.

Driving Through Flash Floods

If the roads start to flood while you’re still miles from home, it’s important to follow these simple steps to make sure you stay safe – even if it means abandoning your car to seek shelter from the rising water:

  • Only attempt to drive through water if you know it isn’t that deep: This is particularly important if you’re on an unfamiliar road, when your lack of local knowledge could mean you’re driving into deeper and more dangerous water. As a rule of thumb, you should never enter water that’s more than 10cm deep.
  • Maintain a slow, steady speed: As you drive into a flooded section of road, maintain a very slow speed to make sure a bow wave doesn’t develop at the front of the car. Often, a car’s air intake is located low down under the bonnet, and just the smallest amount of water being sucked in through it can cause massive damage to the engine.
  • Allow oncoming traffic to pass first: If there’s traffic moving in both directions, this will make flood water choppy and create dangerous waves that could fully submerge your car. On a single carriageway, let other drivers pass before attempting to drive through a flooded section of the road.
  • Don’t drive through fast-moving water: If the floodwater is flowing rapidly, do not attempt to drive through it as your car could easily be swept from the road. Even if the current is slow, deep floodwater is powerful enough to knock your car from the road surface.
  • Test your brakes straight away after driving out of a flood: Excess water on the brakes can lead to a complete lack of stopping power, so you should always check the brakes after driving through a flood. Do this gently over a reasonably long distance, as this will help dry the brakes.
  • Use a low gear to increase the engine revs: When driving through a flood at low speed, water can easily get inside the exhaust, causing damage. To avoid this, stay in a low gear so the engine revs are higher; the force of the air from the exhaust will help keep water out of the exhaust pipe.

Driving in heavy flooding

Checks to Perform After Driving Through Deep Water

Driving through deep water should always be avoided, but if you have to do it, there are a few checks you should do afterwards to make sure your car is still in good working order:

  • Check the brakes immediately after driving through water, per the instructions above.
  • Take a look at the car’s undercarriage for signs of damage. Water can loosen components such as heat shielding and the tailpipe, so you should grab a torch and make sure everything is in one piece.
  • Check the dashboard for warning lights. If even a small amount of water gets in the intake, it could trigger an engine warning light.
  • Take a look under the bonnet. Does it look like any components have been submerged in water? Look for moisture and salt marks, paying close attention to electrical components such as the battery.
  • Place your hand on the carpets in the footwells; do they feel damp? You may need to dry the interior of the car to avoid rust, mould, mildew and bad odours. The best way to do this is to vacuum the car thoroughly, before leaving it in a dry garage with the windows down to air out.
  • Give the car’s undercarriage a blast with a pressure washer or hose. This will remove salt, dirt and harmful deposits that could cause rust and corrosion.

Keeping your car in shape for wet weather driving

Maintaining Your Car for Wet Weather Driving

If you regularly drive in wet weather, it’s important to make sure your car can cope with the conditions. Carrying out simple maintenance checks regularly will help you stay safe on wet roads, giving you the confidence that your car is in good working order:

  • Check the tyres once a fortnight – maintaining tyres at the right pressure guarantees maximum grip in slippery conditions. It will also reduce the risk of a puncture or blowout – because no one needs that when it’s raining!
  • Make sure the brakes are serviced regularly ­– if your car’s brakes have been issued an advisory on an MOT, get them repaired and serviced right away to make sure they’re in a good, safe condition.
  • Check the wipers often – visibility is key in wet weather, so make sure the wiper blades are in a good usable condition. You should replace them once a year for optimum performance, depending on your mileage.
  • Check the lights – you may need to use your sidelights, full beams and fog lights in bad weather, so check them every week or so, and not right before your MOT.

To enjoy complete peace of mind whatever the weather, you can rely on Prestone. Our car maintenance products are developed to work in all extremes, so you can keep on driving no matter what the weather throws your way. To find out more, visit the Prestone website.