What are the chances of natural conception with a one sided hydrosalpinx? is trying without intervention a waste of time ages 30?

Not a waste of time: There are two tubes for a reason. If one side has a problem, the other side may still be functioning normally. If you want to get pregnant its worth trying. Its really the only way to know for sure. Best wishes!

Pretty decent but...: I would estimate that, presuming your other ovary and fallopian tube is healthy, your chances would be good but it might take twice as long as average (on average couples conceive after 7 months of trying). However, you will also have an increased chance of tubal pregnancy. Some docs would advise removing the hydrosalpinx. It would be wise to consult with an OB-GYN doctor.