Well, geese aren't quite as bad as ducks, but they do like to play in the water . . . mine seem to feel like they need to drag grass into their kiddie pools (bath with a snack), and I could imagine that any decorative plantings and what not would suffer. Plus, they are . . . prolific . . . in their droppings . . .
I keep my geese inside a moveable electric fence so I can move them where I want them, and keep them off the road, and away from the neighbors, and also out of the garden. It is expensive though, and you have to move it often or it will get overgrown.
If you don't have a predator issue, or your yard is already fenced, you could try some poultry netting (they sell it at hardware stores) to divide your yard. The geese might chew it to bits though - they tend to chew on things like puppies, even when they won't necessarily eat it. They try doing that to the electric fence when I forget to put the charger on.
Or you could fence the pond area and let them in the rest of the yard -- they do love eating the grass. And the grass grows so plush after goose fertilizer it looks like you spent thousands on the grass. You can also use the wire fencing - the geese can't destroy it, but they will eat all the grass in their enclosure eventually.
People on here have lots of great ideas -- maybe there's some kind of decorative fence that will keep them out of the pond . . .
