Maybe you could try giving him some fresh fruits and veggies with his dinner? I like to give the kids carrots, squash, melon, papaya, mango, and the like. They help to add water without having to drink it. And, yes, my dogs are spoiled. I give them filtered water from a Britta pitcher. Does it taste better, maybe. I did some research a while back on water requirements for dogs, and, of course, I can't remeber the results exactly at this point. But, it was something like 1.5 -2 times the amount of food your dog ate a day. If he eats 1 cup, he needs 2 cups water. The exact requirements are listed in my Disaster Preparedness post from a while back.
You could also try giving Byngham Frosty Paws ice cream for dogs, or one of the other brands. Anything that melts can be considered a fluid--doesn't always have to be water. Ice cubes could be fun to munch on as well. And, although you don't want to do it, you could add some chicken broth or juice to the water bowel.
Hope this helps!