Camera dropped in water - Canon Cameras

If you had immediately fished it out, removed the batteries, and let it dry thoroughly before even attempting to turn it on again, then the camera MAY work again. If you had left the batteries in or tried to turn it on again while wet, your chances are much less.
If your camera doesn't turn on after it's dried out, then you have to either replace or repair it. Given repair costs and the expected life cycle of digital cameras, it's probably more economical to replace it with a newer model. Of course, since you neglected to specify the model of your Canon camera, I can't make that decision for you.