I left it where it landed on the ground next to the large waste bins, it will have been taken by the dustbinmen. Sorry!!
I had thought about chucking it so many times and then that one day, I just had enough of using backpacks that I thought I might as well get rid of it in style (I don't do things by half measures). I looked over the balcony, no cars or people below, so over it went, it was full of water at the time, made one very loud bang, woke the neighbours up, lol.
I know a lot of people worship their backpacks, good for them, but a backpack wasn't for me. Now I just go up the block of flats in the lift and drop a light hose over the back balcony edge and connect it up to my other hose from the van. Quicker and less stress.