Postalmama, I agree with Alfie. I've had a little budgie who fell in my yard a year ago (he's totally splay legged and cannot walk or stand) and I've yet to see him drink...other than the day he appeared. He was totally exhausted from flying for heaven knows how long. He took to food and water immediately, but that was the only time I saw him drink. If he/she is a brand new arrival, it may take a day or so to settle in...
If the little one has been with you for some time, and you are concerned, see an avian vet and keep an eye on the poop. In fact, the new August issue of Bird Talk has a great article with photos of what poop should look like if normal and what is not...it's a good issue to keep on hand. Also, with new fids, it is a good idea to have an avian vet do a check up...it can tell you a lot about the little one's health. My guys have a check up once a year, just to make sure. I strongly recommend developing a relationship with an avian vet...
Keep us posted!