Good idea and I agree, it is better than just filling the bathtub.

Their are a few drawbacks to consider:

1. It doesn't look like you can move it once it's filled. You may want to consider storing some water in smaller (5 gallon or smaller) movable containers too.

2. If you don't get any warning of a impending crisis, it won't be much help.

3. It seems like work to prepare before every major storm. I would prefer to store water in containers that can stay in storage and then be rotated once every 6 months or so. They you will always be ready.