This can easily be completed with the first hidden object puzzle that you come across near the start of the game, in the Antechamber.
After some dialogue with Darius, a hidden object puzzle will become accessible just behind him. You will need to find 13 drops of water within 1 minute. This can easily be done here, with time to spare. Just be careful that your cursor is centered over each water drop to make sure you select it on the first attempt.
Also, be advised that 3 of the water drops are behind objects that will need to be moved first (leaves, broken stone pieces, and rocks) so they are not in plain sight. Simply select the areas that I have double-circled in red and yellow on the solution below to move the object out of the way, and then select the water drop underneath. :)