On Wed, 28 Nov 2012 21:40:07 -0000, Christina Websell wrote:

Knocked off your feet into 4' of flowing flood water would be a very
serious situation,

You just cannot survive 4 feet of fast flowing water. It will knock
you off your feet and you will drown.

I think you missed the word "into".

6" of fast flowing water is enough to wash you off your feet. Once in 4'
of the stuff you will be lucky to survive, depends where it takes you and
what you hit. If you don't get dragged under too much and swept into a
backwater you might be able to haul yourself to (relative) safety.

--
Cheers
Dave.