There are no health benefits to drinking a lot of water when it is not needed by the body. In face you can be doing more harm than good, here's why
It is not necessary to drink water unless your body demands it.
This is a truth which can also be established through logic. The function of kidneys is to remove impurities from the body fluid. When you drink water it is normal for you to intake several inorganic minerals present in it which would need to be filtered by the kidney.
When you keep drinking water unnecessarily no only would the kidneys feel overworked but the continuous accumulation of inorganic minerals can have devastating affects on the kidney's linings causing formations like gall stones.
If you become aware of the amount of chemicals which are added to water in the name of treating it from bacteria, it would keep from drinking it forever. Tap water is rich in chemicals like chlorine, iodine, fluorides which are added to the water during the treatment process. Beyond that there is a presence of minerals like zinc, arsenic, mercury and copper from the pipelines they traverse through.
Suffix to say that you are drinking tap water at your own risk. Mineral water is no different in that there is huge presence of inorganic minerals which can be harmful to your body.