LEGALLY, The U of A is in a Dry County, HOWEVER, as long as you're not drunk or causing problems AND have your beverage in an unmarked cup (solo cups are the best) and you don't try to sneak it into the stadium, you should be fine.
Please do stop by the Hogville.net Tailgate and ask for Wayne. He'll be able to refine this a bit more, but you should be generally safe as long as you're within the tailgating area.