This may sound stupid, but I've actually had pretty good luck with chasing them away! I'm on my tractor every day, so when I see them, I just drive out and send them on their way. During early nesting season, I might chase them away 3-5 times a week. This certainly doesn't keep my pond bird-free, but I think it disturbs them enough that they build their nests somewhere else. After an initial few weeks, they are not a problem for the rest of the year, and I might chase a few away once or twice per month. I still get a few visitors, which don't bother me, but it prevents them from really putting down roots and making a mess of the place.
I also have the option of chasing away what I don't like and leaving the rest. Where I live, the big problem is canadian geese. If you ignore them, they will take over the place. I only see a few ducks and the occasional heron, which I enjoy.