The title is pretty clear by itself.
Is the water that is being produced by the Aqua spell consumable?
Yes, at least Harry thought so.
‘Aguamenti!’ he shouted, jabbing the goblet with his wand. The goblet filled with clear water; Harry dropped to his knees beside Dumbledore, raised his head and brought the glass to his lips – but it was empty. Dumbledore groaned and began to pant.
‘But I had some – wait – Aguamenti!’ said Harry again, pointing his wand at the goblet.
The Water-Making Spell conjures clean, drinkable water from the end of the wand.