Cat Always Drinks An Oddly Large Amount of Water?!

It is actually the opposite for our cats. We rarely see them drink and if they do, they basically just lick a bit from the bowl and that's it. We would still replace the water in the bowl everyday because it gets dirty and filled with their fur, but we barely see it consumed. It does not even get halfway through.

However, now that it's summer, they consume about double than normal, but I still think it's not as much as what your cat takes. I would suggest that you bring him to a vet because it seems he is drinking that much as a reaction to something that he may be feeling. Just like human beings, some cat sicknesses include symptoms such as terrible thirst and so it would be good to watch out as early as possible.