Is the water pure water? as if it was coolant it would smell and have a colour too it, dont confuse it with cats pee please if youre going to taste it though.
But it can be a coolant leak when cold that will seal, up to a point once hot.
Check you coolant level in the header tank, has it dropped?
It could be a leaking headlight wash hose even or screen wash bottle, but that will also smell if its got the additive in it that is should always have?
Or it could just be morning dampness running down from a gutter but that will just be pure water?
Better get down on your knees and taste some, and watch the neighbours arent looking.