With Dhaka experiencing heavy downpours over the past two days and significant waterlogging reported across multiple neighbourhoods, many electric vehicle owners are facing a question that conventional motoring wisdom does not always address clearly: is it safe to drive an EV through flooded roads, and is it more or less dangerous than driving a petrol or diesel vehicle through the same conditions?
The short answer is that EVs are generally more resistant to water than most people assume, and the risks of flooded roads are broadly shared across all vehicle types, but there are specific considerations EV owners should understand before making that call.
The common fear, and why it is largely misplaced
The most widely held concern about EVs and water is that the combination of electricity and flood water creates an electrocution risk. This fear is understandable but is not well supported by how modern EVs are actually built.
EV battery packs are sealed units, typically rated to an international protection standard known as IP67 or higher. An IP67 rating means a component can be submerged in up to one metre of fresh water for up to 30 minutes without damage. The high-voltage systems in most passenger EVs are similarly sealed and insulated. In the event of a significant breach, most EVs are also designed to automatically shut down the high-voltage circuit to prevent electric current from passing through the body of the car or the surrounding water.
Several EV manufacturers, including Tesla, BYD, and Hyundai, have published video footage or documentation showing their vehicles driving through standing water at depth without adverse effects. The evidence suggests that EVs are, if anything, somewhat better suited to shallow flood crossing than petrol vehicles, which risk hydrolocking—a condition in which water is sucked into the engine's air intake and causes catastrophic internal damage—if driven through water too quickly or at too great a depth.
What can still go wrong
That said, the absence of an electrocution risk does not mean an EV is immune to flood damage.
The primary risk is to the electrical and electronic systems that are not part of the high-voltage drivetrain. Components such as sensors, cameras, control modules, charging ports, and infotainment systems, which may carry lower IP ratings or be located in positions more vulnerable to water ingress. Damage to these components can be expensive to repair and may not be immediately apparent after the vehicle exits flood water.
Ground clearance is also relevant. Many EVs, particularly the sedan and hatchback variants that have become popular in Bangladesh's urban market, sit relatively low to the ground. A vehicle with 140mm of ground clearance will reach its limits considerably sooner than a traditional high-clearance SUV, regardless of whether it runs on petrol or electricity.
Finally, braking performance can be reduced on flooded roads for any vehicle. EVs that rely heavily on regenerative braking may behave somewhat differently in standing water than drivers are accustomed to, and that unfamiliarity can itself be a hazard.
What depth is considered safe?
Most vehicle manufacturers advise against driving through water deeper than approximately 30cm, or roughly knee height, for any passenger car. For EVs specifically, several manufacturers publish a maximum wading depth in their owner's manuals, typically in the range of 30 to 50cm for models not specifically designed for off-road use. Crossing water deeper than the manufacturer's stated limit risks voiding the vehicle's warranty in addition to causing damage.
In practice, judging water depth from inside a vehicle is difficult, and the depth of flooding on a given road can vary significantly within a short stretch. If the depth is not clearly visible and assessable, the safest approach for any vehicle, EV or otherwise, is to not attempt the crossing.
Practical guidance for Dhaka conditions
Given the current level of waterlogging across parts of Dhaka, the following general principles apply regardless of vehicle type, though they are particularly relevant for EV owners:
Do not assume that because an EV has crossed shallow water safely before, it will do so again without issue. Conditions change, and repeated exposure to water increases cumulative risk.
Avoid driving at speed through standing water. A bow wave pushed ahead of the vehicle can force water into openings and cavities at much greater pressure than still water would.
If water enters the cabin while driving, exit the vehicle as quickly as safely possible and move to higher ground. Do not attempt to restart an EV that has been substantially flooded before it has been inspected by a qualified technician.
After driving through flooded roads, check the brakes by applying them gently at low speed, inspect the underside of the vehicle for visible damage where safe to do so, and monitor the vehicle's dashboard for any warning indicators in the hours following.
The broader takeaway
The fear that EVs are categorically more dangerous than petrol vehicles in flood conditions is not supported by available evidence. Modern EVs are engineered with water resistance in mind, and their sealed battery and drivetrain systems often make them less vulnerable to flood damage than conventional engines in shallow water.
However, the sensible course of action during conditions of heavy waterlogging is the same for any vehicle: avoid unnecessary travel, assess water depth carefully before attempting any crossing, and do not take risks with standing water whose depth or contents cannot be clearly seen. No mechanical or electrical advantage changes the fundamental calculus that flooded roads carry real hazards, and the safest vehicle in flood water is the one that stays off the road until conditions improve.
