I'd recommend looking at the Sustrans maps
www.sustrans.org.uk and also Canals (all of which do allow bikes on the towpaths, I believe but not all of which are marked on the usual cycling maps).
You're not far from the Bridgewater Canal - from there you can do all sorts of canal/river related possibilities if you add in the Trans Pennine Trail along the Mersey towards Stockport, then on to the High Peak Canal then Macclesfield Canal - there's a 90-something mile loop including the Bridgewater canal that takes in South Manchester and Cheshire if you're feeling adventurous! Not done in myself yet, but maybe one day...