There is a recreation lane set aside at the lap pool I go to. There seem to be heaps of people walking there. Some rehab also after knee recons perhaps as they clearly have set exercises and some have leg weights. It may be worth seeing if someone can recommend some exercises too (?physio). Can you kick at all? I warm up/down with a kickboard just gently kicking. Good luck - it is frustrating when you can't exercise as you want.
FWIW - I went to do laps last week - no point going when it is hot as they opened everything up for fun. (gee that sounds grumpy, lol)