First off, I need to frame my reply with the fact that I went to Berkeley for my undergrad and I am a huge football fan. I was one of those Berkeley undergrads who thought football was a waste of time and money, but I went to a few games and got hooked.
The culture is unfortunately nothing like the SEC. The city despises football (for the traffic, construction, culture, etc.). Graduate students in general are vaguely aware of its existence. But among undergraduates there has been a growing following of football (since 2003 when the program was turned around under Jeff Tedford) and more recently basketball.
If you go to Memorial on Saturdays, at least after you cross Piedmont, it will feel a lot like SEC country with the chants and uniforms and facepaint. I'll be headed back to Berkeley for my PhD, and honestly I'm mostly looking forward to football season. Go Bears!