Surface Drainage Systems collect water that flows over the surface of the earth. It is often composed of ditches, gutters, and storm drains. Subsurface Drainage Systems collect water that has seeped below the surface of the earth. It is often composed of pipes or tiles that are buried underground. Slope drainage systems use the natural slope of the land to move water away from the buildings and structures. Downspouts and gutter system are used to collect water from roofs and direct it away from buildings.