Thanks for posting your query.
What is your present blood pressure?
Nasal bleed may be due to rupture of blood vessels precipitated by increased blood pressure.
There may be presence of abnormal blood vessels getting repeated rupture.
As such there is no correlation between drinking water and dehydration
You should consult with internal medicine specialist and ENT surgeon simultaneously and should go for thorough check up.
You should also go for nasal endoscopy
to rule out abnormal blood vessels.
You should also go for nasal packing for control of blood pressure.
You should also take hemostatic medicines for a short span of time.
Dr. Mayank Bhargava