Custom User Access Possible?

I'm new to Joomla and Community Builder, but decided to get on board because of things I'd heard about CB. My real need, if it's possible, it to allow or restrict editor access in certain areas. Spcifically, the client is a county-wide organization with 45 geographical subdivisions. Each subdivision has its own leadership, and I'd like to give each of those subdivisions their own small corner of the web site. Is it possible to allow a specific user access to their area's pages, but block them from editing someone else's section?

Thanks for your help!

Nobody has any clue on this? I was hoping for at least an "it's not possible at this time" sort of answer.

Guess you can use K2 perhaps for this.