this argument is logically valid, but quite demonstrably wrong, because its first premise is false - one could hose down the streets, the local river could have flooded, etc. a simple logical analysis will not reveal the error in this argument, since that analysis must accept the truth of the argument's premises. for this reason, an argument based on false premises can be much more difficult to refute, or even discuss, than one featuring a normal logical error, as the truth of its premises must be established to the satisfaction of all parties.