The short answer: NO, but it is very water resistant
The long answer: It's nearly impossible to make something completely waterproof, where it could hold water inside without spilling. To do so you have to pretty much make a variation of a zip lock bag. Which we didn't want to do. We have however welded 3 of the 4 sides and added a waterproof zipper.
When you fill this bag with water the main leaking points are on each side of the zipper, which have small leaks. That being said they are quite small and though water leaks, it actually holds shampoo quite well. Shampoo is thicker than water thus not making its way through small cracks and holes as easily.