lol..this is the question of the year.
first of all...it is not normal at all...there should be no water coming inside of the car.
you have to clarify a bit better. you said the water drops from behind the accelerator...if this is the case, which is very very unusual, then it is probably rain water somewhere inside.
you also said you went in 4-8 inches of water on the road...if that is the case...then you have check the rubber moulding on the inside edge of the door. that moulding is there to prvent water from coming inside of the car.
are your floor mats all wet? or are they partially wet? explain a bit more.