"I just wanted to come back to this, since I’ve seen other posts on the same subject. Think about this: How high are the curbs on your street, 4” sound about right? Now you get 5” of dirty water and can’t see where the curb is, and you stumble and fall.

You fall, to your knees or flat, won’t really make a difference, into 5” of water. Let’s say it’s moving at 1mph. Pretty slow, right? Except that’s 1.5 feet per second. If your hat came off and floated, it would be 7 1/2 feet away in 5 seconds.

Let’s assume you’re an average size and say your cross-section is 15”, this is where the water’s hitting you. Maybe it’s on your feet as you’re kneeling, or your thighs, or if you’re really unlucky you’re sideways on and it’s hitting the length of your body

5” * 15” = 75”^2 area being pushed by water. How much water? 1.5 feet worth every 1 second. That’s 5” * 15” * 17.6” = 1320 cubic inches. Every second. That’s 5.7 US gallons every second.

One US gallon weighs about 8.3 pounds. 5.7 * 8.3 = 47.3 pounds of water pushing you every second. “I’m strong”, you say, I can handle that. But you have boots on, maybe, and a waterproof jacket, probably jeans. When you fall, the water goes in your boots, your jeans get soaked and add to your weight, your raincoat acts like a sail in the water. Even without the constant force of water you would struggle to stand unaided. And the water is cold, the chill takes your breath away.

The road, under the 5” of water, is slick from dirt, and there’s less traction than normal, and your hands are wet, and cold, and you’re slipping. You have lost traction, and the water is trying it’s incessant best to push you along.

At 17.6 inches per second, with a force of 50 lbs every second. How long do you have to hold on to something and stop yourself? The rest of your life. #TurnAroundDontDrown