The zipper isn't close to waterproof, so not sure what's supposed to be waterproof. I filled it up and tiped on its back. Water poured out of the zipper, when I pressed on the side, air and water escaped as well. It looks rather splash proof, but it's far from waterproof. The lining is one piece and I assume it's waterproof.
The fabric between the outside and inside is now wet after tipping it over on its side and letting less than half of the water drain. Both the lid and the sides are wet. The seam at the top where the outside and inside linings join is not watertight and therfore able to let water in. I don't suspect it will evaporate very fast.
Probably going to return it and realize that to get it right, it may cost more.
Let me know if you've got more questions.