Therefore , the harbour was changed to a small man - made island farther out in the river .
Another setback was the necessity to completely redesign the harbour because the fast flowing Nelson River was building up silt on both sides of the wharf .
The harbour was changed to a small man - made island farther out in the river .
Another setback was the necessity to completely redesign the harbour because the fast flowing Nelson River was building up silt on both sides of the wharf .