Wyoming Office of Homeland Security
Turn Around, Don't Drown
Only six inches of fast-moving water can knock over a person. It only takes 12 to 18 inches of fast-moving water to carry away most vehicles including large SUVs. If you come to a road that is covered with water turn around, you will likely not know the depth of the water or the condition of the road underneath as roadbeds may be washed out.
Whether driving or walking, any time you come to a flooded road please turn around, don't drown! Never enter standing or moving water to cross a road.