As a civilian, once you've registered and completed the background do you have to do that everytime you visit the water park for that season?

Yes, everytime you enter a military base ID must be checked.

Yes. Even soldiers must have their identification checked every time they enter the base.

I'm not sure. You would probably have to ask the personnel at the park. I would assume yes if you do not have and military affiliation.

Okay, thanks everyone.

Once you register on the installation, everytime you go through the gate you will have to get a pass. It will be a quicker process after you register . its tiresome but this helps protect the post..