Seacue,
At my airport, we do an "Opposite Direction" operation maybe a half dozen times a day. In our case, the tower controller would first have to check with the finals controller, whose airspace the departure will transit, and then with the feeder controller who will actually work the departure out. If either of them say no, then, of course, we can't. We only do it during light traffic of course, usually late night or early morning. It's pretty hard to provide standard radar and wake turbulence separation on an opposite direction op while still complying with noise abatement procedures, whcih require the departure to climb straight out for a few miles if it's a turbojet. On then other hand, a FedEx Caravan can do a 90 degree turn at mid-field, so little problem, except that if we let the Caravan do it all the time, then EVERYBODY wants to do it too.....
