paul,don,t think you could be anywhere else from the description of your walk you may have got to dover basin if the water mentioned was close to the canal(i. e. 20ft reed bed then water) have a look on www.os maps sd612001,to see if it makes things a bit clearer.
After telephone conversation with Ian Woosey I think the area I was in this morning was Lightshaw Hall Flash. I'd parked up at Plank Lane and walked towards Abraham on the Leeds-Liverpool canal.
I viewed the flashes from just past a farm with houses set back from the canal on opposite bank.
I could make out at least 50 Lapwing, 2 Oystercatcher, 2 Redshank and at least one Pink-Footed Goose.