I have a 3 yr old calico persion cat that drinks lots and lots of water. She is about 11 lbs and seems to be perfectly healthy( shots current) . It seems like I am constantly scooping up piss balls out of her litter box. Why is she thirsty?

So, your cat has a drinking problem, eh?

The following is from the site, Cat Drinks a Lot

Health Issues

Q.: My cat drinks incredible amounts of water. Is this normal? I should think it drinks about a mug a day. We have several cups placed around the house, so it can have water all the time, and this it makes a lot of use of!
It has to be said, too, that it eats dried food exclusively, but never the less I think it drinks really much. What can be the reason?

A.: If the cat has always drunk this much (on dried food) and it seems healthy, I think one must conclude that this is this individual cat's requirements. It is very individual how much a cat needs to drink.
Cats drink considerably more, if they're on dried food. Canned food contains a lot of water (up to 80 %), so if the cat lives out of this, it may have most of its water requirements covered by the food, and you will rarely see it drink.
If the large water requirement has arisen lately, however, I think you should have the vet examine the cat; diabetes is one of several possible explanations. Anyhow I think you should mention the matter to the vet the next time, you talk to him/her, for example at the annual vaccination consultation.