These were large bolders that had to be placed with large machines. The path that the machines took depressed the soil and caused a drainage/grading problem. Much of the newly placed topsoil and plants were washed away. All the water from the higher part of the property and my nieghbors yard, washed down to the lowest area.

I've piled up muddy soil, sticks and leaves to interupt the path and redirect the water. I wish I had known this before. I hope someone else can benefit from my experience.