Sorry that you are having a problem with excessive tearing. This is not an uncommon issue. It has nothing to do with your water intake.
In general, the cause is either excessive amounts of tears being produced (irritation) versus a blocked exit and overflow of normal amounts of tears. (bad plumbing).
In the absence of any irritation of your eyes, the problem is probably an obstruction to the normal exit pathway for your tears. Tears exit through small openings called puncta on the edges of your eyelids near your nose. Through those openings, the tears travel to a tear sac near your nose then into your nose and eventually into the back of your throat. That is why you have to blow your nose after your cry. It is the normal pathway for tears exiting the eye.
The tiny openings on the eyelids can become blocked as well as can any of the channels which lead into your nose. This will cause tears to "spill" over your eyelids. Sort of like a blocked drain spout with rain water spilling over the gutters of a roof. If the eyelids are not positioning tightly against the eye or there is any loose eye skin blocking the entry into the tear duct, this can also cause spillover tearing.
An examination by an ophthalmologist can lead to the precise cause of excess tearing. If the symptoms are substantial, the eyelid or tear duct "plumbing" can be surgically repaired.
Believe it or not, a common "irritation" cause of excess tearing is dry eyes. When the surface of the eye dries to an irritating degree, your eyes automatically and reflexively tear causing excess watering.
The answer to your problem is to have a comprehensive examination by an ophthalmologist who can make a diagnosis and suggest treatment if necessary.