I just noticed at the garage a slick on the concrete underneath the front bumper, seems to be coming from behind the driver side aux rad.

You can see the drip forming at the bottom of the arch liner. Its coming out at quite a rate!
Can I drive around with a bottle of water to top up for now until i book it in on Monday, or is putting water and not kosher coolant in the tank a definite no no in these cars?