Carry bottled water while you are on an expedition, picnic etc this will keep your energy level high and let you enjoy the most. It is better than a cold drink which leaves you dehydrated. This is the time when you miss having water cooler only if these were battery operated you could carry it everywhere.
For an overnight stay, it is better to arrange for water deliveries at the place of stay, if there is any doubt about the water quality in the new place. High energy can only make such picnics a success and water is often ignored resulting in tiredness by the end of the half day.