Apart from lethal removal, habitat modification is the most effective means of reducing nuisance goose problems.
Stop All Feeding
If you are feeding the geese, stop. They, like all animals, are attracted to food. If you are trying to keep geese out of a public area, put up "no feeding" signs.
Tall Grass and Shrubs
Geese like short, lush, mowed grass. They need space to land and take off, and are also uncomfortable feeding in areas where their view of potential predators is poor. Allowing grass to grow to a height of a foot or more will reduce the attractiveness of the area to feeding geese. If geese are walking onto your lawn from a pond, let the vegetation along the shore of the pond grow tall, plant shrubbery, or create a stone barrier along the shoreline. Planting shrubs and small trees interspersed throughout a feeding area (lawn) can be very effective.
Fence Along the Shore
Because geese normally rest on open water or along the shoreline and then walk out to grassy areas to feed, construct a fence (at least 30 inches high) to prevent access to the lawn. This method works best during summer molt (mid-June to mid-July), when geese cannot fly. Use wire (e.g., 2 x 4 inch) mesh, plastic, or nylon netting. An alternative method is to use two parallel monofilament fishing lines (at least 20-pound test) 6 inches and 12 inches above the ground, and secured by stakes every 6 feet. Make sure the fence completely encloses the pond. When the birds have the ability to fly, this fencing loses much of its effectiveness.
Electric fences are another alternative and have been effective in excluding geese. Use two strands of at least 17-gauge wire, 8 inches and 16 inches above the ground, or 3 strands at 5, 10 and 15 inches above the ground.
Keep Geese out of the Water
To keep geese off your pond (so they cannot walk out and feed), consider constructing a system of suspended wires over the water to deny them access to the pond surface. Geese prefer to land and take off from open water. This works best for areas under one acre that are not used for other recreational purposes (swimming, fishing, paddling, etc.). Single strands of 14-gauge wire, 80- to 100-pound test monofilament fishing line, or stainless-steel cable should be strung on a grid pattern across the water with 10 to 15 feet between lines. Each line should be suspended 12 to 18 inches above the water’s surface. Also, use perimeter lines (6 and 12 inches above the ground) to keep geese from walking in under the grid lines. Attach brightly colored flagging or tape to the lines to make them more visible.
Anthraquinone (creates digestive irritation) and methyl anthranilate (tastes bad to geese) are registered repellents for the control of Canada geese feeding on grassy areas. They are applied to the grass and reapplication is necessary after mowing or heavy rains. There are several commercial products available that can be purchased at garden centers. Because they are expensive and must be reapplied after rainfall they are very practical for small lawns, such as those bordering a lake or pond, but not well suited for large expanses of turf. Follow the label instructions for application.