Well I have had lots of success up round that way in the past, but more recently I know there has been some trouble round there. About 5 years ago I was attacked by a nutter with a baseball bat at one of the reservoir sites. Fortunately he only beat the shit out of the bonnet of my car and threw eggs. I have also seen some videos of people driving through one of the laybys 'looking for doggers and gays to beat up'. Not been out round there for a couple of years, but I would take care and make sure you get some local knowledge.
There are some fantastic sites round there, would be a real shame if Dogging has died roundd Rochdale.