My dog drinks so much...it has me worried..?

So my dog just drinks tons of water a day sometimes i've seen him drink for about 3-4 minutes straight and i have to refill his water bowl up...he weighs about 150 and is a puppy german shepard...i love him very much and i just sometimes get worried that about the constant drinking....in the middle of the night i have to fill it up because he sometimes drinks it all while i am asleep and i also fill it up sometimes between 2-3 times a day and this bowl can hold a lot of water i can't give an actually amount though probably like 3 bottles of ozarka water or 4. Anyway is there some kind of problem he might have or can he get sick off of drinking too much. I would like to know if i should take him to a vet or something.