How to drive through standing water

First, let’s acknowledge that we all have heard the warnings not to drive through standing water. That said, today’s various photos provide a great chance to evaluate the worst way to do what you’re not supposed to do in the first place.

People blast through, apparently figuring if you go through really fast, all the electrical components under the hood won’t know you’ve just blasted through water. By the time they realize it, you’re back on terra firma. Stupid electrons.

Pretty good form being used here by car 2. The owner of car 3 will be wondering in a couple of weeks what the smell is.


Here’s a critical question. If you have a red light, but you’re in water, do you stop or keeping going?

Sometimes you make it. Sometimes you don’t.

A car is stalled on a flooded S. James Avenue near W. 50th Street in Minneapolis as flash floods ripped through Minnesota June 19, 2014. Jeffrey Thompson/MPR News

If you’re going to drive through water, do the wrong thing the right way. Here’s some tips from the Smart Driving website:

It’s also worth checking where the air intake is on your engine. If water is sucked into the engine it will stall, but worse than this, it can cause severe damage that will require the engine to be stripped down in order to bring it back to life. Do not try to restart an engine that has sucked in water – the plugs or injectors should first be removed to allow the water to be expelled.

Some four-wheel-drive vehicles are equipped with high level air intakes allowing them to be driven through water several feet deep, however, you can say goodbye to your deep pile carpet and Gucci Sneakers if you attempt this! And as mentioned above – even 4×4 vehicles can be washed away in flowing water. If the water is fast-moving – even 30 centimetres depth of fast-moving water could wash your car off the road.

Where possible flooded roads are best negotiated by one vehicle at a time. wait for approaching vehicles to clear the water before you start to drive through.

Using first or second gear (L or 1 in an automatic) drive slowly to avoid creating a large ‘bow wave’ (a small wave can be helpful but too much and the water can wash back into the engine). Slipping the clutch and revving the engine will also help to keep the exhaust clear and keep the engine running if water splashes onto the electrics. In an automatic keep your foot on the gas in the lowest held gear and use the brake to control your speed (and hope for the best!).

In some cases a stalled engine can result in water being sucked back through the exhaust into the cylinders – this can cause extensive and expensive damage. Do not change gear because this can also cause water to be sucked back through the exhaust (due to the change in engine speed and manifold depression).

Another potential cause of damage in floods is a cracked catalytic converter (‘cat’). The ‘cat’ is part of the exhaust system and works at high temperatures; if it comes into contact with very cold water there is a possibility that the rapid contraction of the metal could crack the welded sides – OK if you have plenty of money to replace it!

If your wheels start to lose grip partway through a flooded section it could be that the car is trying to float. To counter this, open a door and allow some water into the car, this will weigh it down, enabling the tyres to grip again – it’s probably best to get a passenger to do this so that you can continue revving your engine and slipping the clutch.

After driving through a flooded section of road or a ford across a river, test your brakes (whilst still driving slowly) and be prepared to drive them off by touching the brake pedal very lightly with your left foot (practice this on an empty stretch of road next time you go out driving to discover what very lightly means!).

Once through the puddle, you’re good to go. Just set aside a little time to figure out how you’re going to pay for the new brake rotors, which will probably be warped from the shock cooling.

Also, since the oil pan is the lowest part of the engine, there’s a fair chance some water might have seeped in. Wherever you’re going, you might want to pull in for an oil change.

Meanwhile, here’s the list of highway closings from MnDOT as of mid-morning:

Highways CLOSED include:
• Hwy 19 west of Gaylord
• Hwy 19 east of Henderson
• Hwy 93 south of Henderson

Highways with RESTRICTIONS or water over roadway include:
• Hwy 4 between Sleepy Eye and Fairfax – reduced to one lane w/pilot car
• Hwy 22 north of Gaylord – restricted with water on roadway
• Hwy 112 west of LeCenter – open with water on the roadway
• Hwy 169 SB between St. Peter and LeSueur – use caution – status being monitored

• Hwy 13 near Kilkenny
• Hwy 14 west of Springfield
• Hwy 19 west of Henderson
• Hwy 83 north of St. Clair – watch for workers

Update The city of Minneapolis closings:

Cedar Ave at Minnehaha Parkway is flooded and closed. Barricades will be up shortly
Minnehaha Parkway from Longfellow Ave to Bloomington Ave is flooded for vehicles. Barricades will be up shortly.
Minnehaha Parkway is impassable from Pleasant Ave S to Nicollet Ave S. Barricades will be up shortly.
Minnehaha Parkway from Bloomington Ave to 22nd Ave. The bike and walking paths are flooded.
Dean Parkway at West Lake Street is flooded. Barricades will be up shortly.
Lake Harriet Parkway – lower road
Lake Nokomis walking and biking paths – 53rd Street to 22nd Avenue and Cedar Avenue to Derby Avenue
Lake Hiawatha walking and biking paths from Minnehaha Parkway to 44th Street

  • Paul

    The first photo is explained by the make of the car. Everything you do in a Porsche has to be as fast as possible – including damaging it with water.

    • If I had a Porsche, I wouldn’t even take it out in a light drizzle.

      • joetron2030

        That’s a Cayenne, though. It’s got all-wheel drive. I’ve watched quite a few test drives of it where the reviewers have gone to great lengths to test its off-road capabilities and it always performs very well.

        • $56,000!!!

          • joetron2030

            I doubt anyone who owns a Cayenne only got the base model. Once you start adding in the options (and with Porsches everything is an option), you’re easily over $70K.

            I don’t understand how people can afford to own them either unless they’re leasing them (with a ridiculously low annual mileage allowance) or buying them used.

            (EDIT: Corrected my spelling to reflect the automaker and not a part of your house. LOL)

          • I suppose if I were leasing one, I’d really blast it through the water to get my money’s worth.

          • joetron2030

            Drive it like a rental!

          • Ralphy

            Seems like most every SUV advert on TV shows the vehicle plowing across a stream at some point (never mind that it’s illegal and will severely damage the stream’s eco-system) – if you have a testosterone supplement with 4 wheels, water is not going to slow you down!

  • jon

    the “As fast as you can” method has the benefit of hydro planing, you get to stay above the water the whole time… just hope that there isn’t a need to turn while you are doing it, because that car is going to either go straight over the water, or sink into it, you won’t have any control over the situation once the tires start traveling over the top of the water.
    And, of course, if you have decent tires they are designed to NOT hydroplane…

    If you have the time to stop and let your car cool down (get the cat, oil pan, and rotors all to ambient temperature) that will help prevent thermal shock… though if you are in such a hurry to get where you are going that your willing to risk your car and possibly life for it, then you probably don’t have time to stop and let everything cool down before you do something stupid.

  • Dave

    Oh come on. That guy’s driving a Porsche thru Edina. He has god on his side.

    Besides, couldn’t they just sop up all that water with cake?

  • I admit to using the “drafting” technique, in spite of its obvious danger of collision. Basically, follow — closely — the person in front plowing through. Since he/she has displaced the water, you have substantially lower water to drive through.

    Of course, you have to get this just right or you end up like the person in car 2 above, who’s getting swamped by the bow wave created by car 1.

  • Jim G

    Is it time to bring the 12 ft. boat and 6 horse Johnson out yet? BTW, it’s for sale.

  • joetron2030

    Bob, this:

    “People blast through, apparently figuring if you go through
    really fast, all the electrical components under the hood won’t know
    you’ve just blasted through water. By the time they realize it, you’re
    back on terra firma. Stupid electrons.”

    gave me a good chuckle. I needed that. Thanks!

  • joetron2030

    Also, I’m commuting by pontoon until further notice.

  • Dave

    Correct me if I’m wrong, but in theory transient water shouldn’t hurt the electrical components under the hood. They are designed to get wet from rain, splashing, etc. It’s why you can steam-clean an engine. It’s when water gets in the intake that the car stalls.

    Now, I can’t say anything for the components in the dash or elsewhere inside the cabin.

    • There’s no design that I’m aware of that prevents copper wiring and connectors from corroding, which is the primary cause of electrical failures. That’s long term, of course.

      Short-term, as evidenced by the number of pictures I saw today of cars stalled in water not yet reaching the intake, I’d say there’s a design flaw somewhere.

      • Dave

        How do you know they stalled because the engine died? Maybe the owner just parked the car and left.

        • Are you referring to the picture of the guy whose car is in the middle of the pond, it’s raining hard, and he’s standing in water with no boots and the water up to his knees?

    • CHS

      That’s partly true, there are a few other critical items that can tolerate some rain and splashing, but will short out under excess water: If your CPU gets wet (the computer that controls everything) you are done for. Less expensive (but easier to screw up: the alternator) No power means you’re having a short trip. Older cars can get wet distributor caps, and they won’t run again until they are dry. Even in vehicles designed to take lots of water (Jeeps, Land Rover), there are things that unless waterproofed will kill your engine in too much water.

  • I wonder what the scenario is if you’re driving through water in an electric car, say a Tesla, Leaf, or Prius in EV mode. There’s no air intake to worry about, but what about a battery or electrical components?

    My uneducated guess is your car would be better off, since there is no combustion engine to harm, and the electronics should be all fairly well protected. But, in moving water, you could still run into trouble.

  • Jeff C.

    Hmmm…Maybe I should have bought that Amphicar…

  • joetron2030

    Where’s James Bonds’s Lotus that’s submersible when you need one?!?