If you have a population of Canadian Geese living on your property, you have my sympathies. You've probably already tried as many remedies as you can get your hands on to get rid of these large pests and nothing has worked consistently over time.
Talking with several golf superintendents who have tried just about everything on the market, the one item that does work is putting a grid of black monofilament lines (like heavy duty fishing line) across the waterway.
The grid consists of about 25 lines in each direction and about 2 to 3 feet above the surface. When the geese come in to land, it looks to them as if there are twice as many wires because of the reflection on the water. Besides the visual confusion, if the geese actually do try to land, they will hit the lines and be scared off.
Female geese are the ones you need to move. If she leaves, the male goes with her.
The longer geese sit on the nest, the more defensive they become.
Use more than one element in the deterring process. Geese are very adaptable and will quickly learn that a decoy is not going to hurt them. Change tactics often.
Visual harassment does work well by itself. Add other stimulants, especially sound.
Begin the disruption process in the fall when the first migrants arrive to scout the territory. Early is better than later.