The heavy rains that affected Istanbul on October 14-15, 2026, caused numerous vehicles to be submerged and swept away. How drivers should react when stranded in floodwaters and whether submerged vehicles can be reused emerged as a significant safety concern.
Instructor at Üsküdar University, Occupational Health and Safety Department, and Road and Traffic Safety Consultant Özgür Şener, assessed the dangers of driving in floodwaters, what to do if stranded, and the potential damages to vehicles exposed to water.
“The fact that the vehicle in front of us can pass does not mean we can pass too”
Özgür Şener stated that the biggest danger when driving in floodwaters is the inability to accurately assess the depth of the water and the actual condition of the road. He said, “Water can conceal potholes, open manholes, collapses, and obstacles dragged by the current on the road surface. Furthermore, regardless of the water depth, vehicle weight, and design, it can cause the vehicle to lose traction and control.”
Emphasizing that one should not attempt to pass by visually estimating the water depth, Özgür Şener continued:
“We should not drive into puddles and floodwaters whose depth and ground conditions we do not know and are not sure are safe. The fact that other vehicles have passed through the water does not indicate that the route is safe. The ability of the vehicle in front of us to pass does not mean our own vehicle can pass. If the road is covered with water, we should turn back if possible and choose an alternative and safe route. For the sake of saving a few minutes, we could endanger both our own lives and the lives of others in the vehicle.”
“30 centimeters of fast-moving water can sweep away many cars”
Şener stated that the dragging force of floodwaters is often underestimated, drawing attention to the warnings from the U.S. National Weather Service (NWS).
Özgür Şener provided the information, “While approximately 15 centimeters of fast-moving water can knock an adult off their feet, 30 centimeters of fast-moving water can sweep away many cars. Approximately 61 centimeters of fast-moving water can also sweep away SUVs and some pickup trucks.”
Şener noted that the weight of vehicles does not provide absolute protection against floodwaters, stating that one should particularly avoid attempting to proceed in roads with strong currents.
“When stranded inside a vehicle, the priority should be saving lives, not the vehicle”
Özgür Şener explained that being stranded inside a vehicle during a flood can become life-threatening within minutes, stating that water levels and current intensity can change rapidly.
Özgür Şener stated that one should not act in panic in such situations, saying, “If the water is rising, the current is dragging the vehicle, or the vehicle is losing control, one should not attempt to proceed. If the engine stops, do not try to start it repeatedly. The priority is not to save the vehicle, but to protect the lives of those inside.”
Şener said that drivers should, if possible, contact the 112 Emergency Call Center to report their location and the number of people in the vehicle, emphasizing the importance of informing rescue teams about the condition of passengers, especially children, the elderly, or those with mobility limitations.
“It's not always right to exit the vehicle immediately in every flood event”
Şener emphasized that the decision to exit a vehicle during a flood should be made based on the current danger, stating that getting out can be fatal in situations where fast-moving water surrounds the vehicle.
Özgür Şener made the following assessment:
“If fast-moving water surrounds the vehicle, it may be safer to stay in the vehicle and call for help as long as the water is not rising inside. Because getting out of the vehicle and entering fast current can cause a person to be swept away and drown. However, if the water level starts to rise inside the vehicle, one should not wait, and a safe evacuation option should be considered. Additionally, other vehicles or solid objects carried by the flood can also pose a serious danger.”
Özgür Şener stated that in situations where the water level rises, vehicle doors may not be opened due to water pressure, and said, “If possible, the option of exiting through the side windows should be considered before external conditions worsen further. Seatbelts should be unbuckled, and assistance should be provided to children and passengers with mobility difficulties. If the windows are not electrically operated, exiting through a breakable side window may be necessary. Front windshields are usually laminated glass and will not break. It is important to have a safety hammer in every vehicle and keep it in an accessible place.”
Özgür Şener also emphasized that those who safely exit the vehicle should not attempt to walk against the current or swim across, advising them to reach a high and safe point and not return for items left in the vehicle.
“Absolutely do not start the engine of a vehicle stranded in floodwaters”
Özgür Şener stated that the receding of floodwaters does not mean vehicles can be safely reused, adding that invisible mechanical and electronic damages can occur in vehicles exposed to water.
Şener warned that restarting the engine in particular could exacerbate existing damage, and said the following:
“If the vehicle has entered water, been submerged, or if water may have entered the engine compartment, the engine should not be started, and the ignition should not be engaged. Attempting to move the vehicle could worsen existing damage. If the vehicle is in a safe place and approaching it poses no danger, photos of the damage can be taken. The insurance company should be informed, and appropriate rescue services should be called.”
Özgür Şener also stated that vehicles exposed to water should not be moved by pushing or improper towing, and noted that wet electrical connections and control units should not be interfered with.
“If the engine ingests water, it may need to be completely replaced”
Özgür Şener explained that one of the most serious problems floodwaters can cause in engines is hydraulic lock, stating that this condition can lead to severe damage to the engine's internal mechanism.
Özgür Şener said, “In internal combustion engines, pistons operate by compressing the air-fuel mixture within the cylinder. However, water cannot be compressed as easily as air. If sufficient water reaches the cylinders through the air intake system, the upward movement of the piston can be obstructed. This condition is called hydraulic lock.”
Regarding the consequences of hydraulic lock, Özgür Şener provided the following information:
“As a result of hydraulic lock, connecting rods can bend or break; pistons, the crankshaft mechanism, and other engine components can suffer severe damage. Depending on the extent of the damage, the engine may need to be completely replaced. Even if water has entered the engine while it is stopped, engaging the ignition can worsen the existing situation. Therefore, the ignition should not be engaged to test whether the engine is working.”
“Even if the vehicle starts, safety systems may have malfunctioned”
Özgür Şener stated that floodwaters can also damage electronic systems in modern vehicles, warning that damages may sometimes appear days or weeks later.
Özgür Şener said, “Modern vehicles contain numerous electronic components such as engine management, ABS, electronic stability control, airbags, seat belt pretensioners, parking sensors, and driving assistance systems. Floodwaters can cause short circuits, insulation problems, and corrosion that develops over time in these systems.”
Emphasizing that electronic malfunctions in the vehicle may not be noticed during the initial inspection, Özgür Şener said, “Even if the vehicle starts initially, warning lights may illuminate afterward, sensors may send faulty signals, or some systems may become inoperative. More importantly, the damage may not be limited to comfort features. Safety-critical systems such as ABS, electronic stability control, and airbags also need to be checked.”
Özgür Şener stated that floodwaters reaching up to the vehicle floor can leave moisture under carpets and insulation materials, leading to mold and unpleasant odors, and over time, a deterioration of the interior air quality.
“Delayed fire risk in electric and hybrid vehicles”
Özgür Şener pointed out that post-flood risks can reach different dimensions in electric and hybrid vehicles, stating that high-voltage battery systems require special safety precautions.
Özgür Şener said, “Battery packs, electric motors, and high-voltage cables can be affected by flooding or physical damage. This situation can create a risk of electric shock, short circuits, and fire. The effects of battery damage may not always be immediately visible. Physical damage or water exposure can, under certain conditions, lead to delayed heating and fire risk.”
Emphasizing that electric and hybrid vehicles exposed to floodwaters should not be operated or charged without assessing battery safety, Özgür Şener continued:
“Battery packs, high-voltage cables, and damaged electrical connections should not be touched. If smoke, abnormal heating, hissing, or unusual sounds are noticed, one should move away from the vehicle and notify emergency teams. The vehicle should be transported according to the manufacturer's recovery instructions and by trained teams in this field.”
Özgür Şener stated that vehicles with suspected battery damage should be kept away from homes and enclosed spaces, noting that the safe distance and how vehicles should be positioned must be determined by expert teams.
“The receding of water and the vehicle starting does not mean it is safe”
Özgür Şener stated that it is not enough to only check the engine of flood-affected vehicles, adding that the brakes, steering, transmission, and electrical systems must also be thoroughly examined.
Özgür Şener, “After a flood, the braking system, steering components, transmission, differential, wheel bearings, and electrical wiring may be affected at different levels. Problems related to water and contamination can be observed in braking systems. Water mixing into transmission or differential fluids can lead to mechanical damage. Corrosion developing over time in electrical connections can cause malfunctions days or weeks later.”
Emphasizing that submerged vehicles should be transported with appropriate recovery equipment, Özgür Şener suggested that the towing method should be determined according to the vehicle's transmission and drive system, and a flatbed tow truck should be used when necessary.
Özgür Şener warned, “The fact that the vehicle is running or can move a short distance does not mean it is safe. Normal use should not commence until the brakes, steering, drivetrain, electronic systems, and interior components have been checked.”
“There are two fundamental rules for vehicle safety in flood conditions”
Özgür Şener stated that in vehicles exposed to floodwaters, damage cannot be assessed solely by looking at the water height reached, adding that the duration of exposure and the mud and contaminants in the water also affect the extent of the damage.
Emphasizing that vehicles must be inspected by an expert service, Şener concluded his words by saying, “The priority for life and vehicle safety is not to enter water with the vehicle. If water has been entered for some reason and one has exited safely, it is important not to exacerbate vehicle damage. These are the two fundamental rules of vehicle safety in flood conditions.”
