Despite the obvious dangers of floodwater to car and, at worst life, one in 20 motorists (5%) admit to having driven through floods only to have their vehicles grind to a halt, either still in the water or just after coming out, according to research carried out by the RAC*.

While the vast majority of those (63%) were lucky to get away without suffering major damage once the vehicle had dried out, 20% said their cars needed repairing, and 7% said the situation was irretrievable and led to the vehicle being written off by their insurance company.

Nineteen per cent admitted to having to abandon their broken-down vehicles in the floodwater and 69% of those had no choice but wade out. Six per cent, however, had to be rescued by someone else.

The RAC Opinion Panel survey of more than 2,228 motorists also found that two in five (18%) confessed to having started to drive through a flood and then wishing they hadn’t. Three-quarters of those (74%) then said they just ploughed on through while a more cautious 13% said they decided to reverse out, and an unlucky 13% ended up getting stuck.

Despite the numbers who have either had their vehicle stop working as a result of driving into floodwater, the biggest risks appear to be very well understood with two-thirds of motorists (66%) correctly identifying water being sucked into the engine as the greatest danger – an issue that can very easily cause catastrophic damage and lead to a vehicle being written off. Three in 10 (29%), however, felt the biggest risk was was the electrical system becoming saturated.

The majority of drivers polled by the RAC were relatively careful with their decisions when encountering floodwater of unknown depths. A third (35%) said they would turn around and go another way, 31% would watch to see if other vehicles made it through before they decided to and 29% would try to gauge how deep the water was and decide whether to go through or turn around.

In terms of the depth of floodwater motorists are prepared to drive through, most (62%) would not risk anything above six inches (15cm) up their tyres. A braver 28% said they would be happy to go through any water up to the bottom of their car doors – this, of course, could prove fatal for a vehicle as it is at the height of most exhaust pipes. And depending on the circumstances it could also present a danger to both drivers and passengers.

But sometimes it is not the decision as to whether to drive through a flood that catches motorists out, it’s where they choose to park. A very unlucky 3% have left their vehicles parked only to return to find them standing in floodwater.

RAC spokesman Simon Williams said: “It’s good to see the vast majority of motorists are aware of the risks associated with driving through floodwater. But it’s also worrying that there are still lots of people who seem oblivious to the fact they are gambling with their vehicles’ futures by attempting to drive through water that is too deep, as well as potentially putting themselves and their passengers at risk.

“The consequences of water being sucked into a car’s engine are usually catastrophic, leading the vehicle being deemed an insurance write-off. Any decision to drive through floodwater must be extremely calculated as motorists could very easily end up paying dearly for one bad decision. Caution is definitely the best option.

“If there’s any element of doubt about whether the water is shallow enough to drive through, then the sensible thing to do is to turn around and go another way. Sometimes though the pressure of being ‘on time’ is too great and causes people to take risks they really should not.”

Nicola Maxey of the Met Office said: “In periods of heavy rain and potential flooding it is important to keep up to date with the latest forecast and warnings for your area ensuring you’re aware of the latest situation. You can do this by checking the Met Office website for the daily forecast or our warnings page, or you could download our weather app which will ensure you can keep up to date while you are out and about. With the latest weather information for your area you will be able better prepare for what is in store and plan your activities accordingly.”

The RAC has advice for driving through water and floods.