" Drain manholes in a Drainage system serve a few purposes. They act as collection points for two or more Drain pipes coming from different directions and they also provide access to the Drain pipes for maintenance purposes. In storm gully Drains they can also trap larger pieces of debris and sediment to stop these reaching the outlet point of the Drain. Usually manufactured of concrete or plastic,  Drain manholes typically comprise large circular chambers, of a size that enables a man to climb down into them. "

" The Drain pipes in a land or sewer Drainage system carry the water from the source point to its final destination. The design of a network will take into consideration the quantity of water a Drain pipe will carry to size it accordingly, with Drain pipes typically having a circular profile. The manufacture of Drainage pipes involves various materials, with common options including plastic and concrete. Sewer Drainage systems typically use solid Drain pipes, storm gully systems can have a combination of solid and perforated Drain pipes. "