Water is a normal by-product of combustion. If you are spending a good bit of time idling, it may be condensing in your exhaust system & spilling out the tailpipes. Kinda like Grandma's old 455 Bonneville did because she never pressed the gas pedal more than 1/8" down.
Taste a fresh drop of the water. If it's sweet, spit it out, it's coolant. If not, it's probably just condensation.