Drainage Classifications

Drainage systems move water from one place to another. There are natural drainage systems moving water from ponds, lakes and rivers to eventually, in some cases, empty into the sea. Man-made drainage systems use pipes, canals, tunnels, trenches and ditches to move water from buildings, roads or farms.

Agricultural Drainage

When soil becomes too saturated to absorb any more water during irrigation or rainy season, the excess water forms on the surface and becomes stagnant. To enhance crop production and conserve soil, the water is drained. This is done through natural or artificial means. Natural agricultural drainage is when water flows on its own from farms to rivers, lakes or swamps. Artificial methods involve either surface or subsurface drainage systems. Surface drainage removes water through creating slopes and ditches. Subsurface methods remove water from the soil using perforated tubes called tiles. Water seeps through the small spaces in the tiles and flows to a collector drain.

Geomorphology Drainage System

In geomorphology, lakes, rivers and streams create a drainage system governed by the topography of the land. The water is emptied into larger water bodies like the ocean. Examples of geomophological drainage system include, trellis, radial and dendritic drainage. A trellis drainage pattern forms when two tributaries join the main stream at right angles to form a rectangular pattern. Dendritic drainage forms on a sloppy surface and consists of several tributaries resembling tree branches and joins large rivers. They develop on a land surface where the underlying rock has a uniform resistance to erosion. In radial drainage, streams move outwards in different directions from a central high point.

Household Drainage System

A drainage system is usually required in almost every kind of structure. It is important to drain the excess water coming from the building or from the surrounding landscape soon as possible. Sewage drainage is one of the essential public facilities and is used to drain both industrial and domestic waste water. In a house, drainage systems include the shower, sink, and tub and the pipes. The system also requires a ventilation pipe to allow gases and odors to escape through the building's roof. The waste water moves from the house to a place of disposal or to a treatment area.

Highway Drainage System

Highway drainage systems drain rainwater from roads and footpaths. Highways need to be drained effectively to ensure traffic safety and to maintain the roads. Inadequate drainage often leads to road destruction. Pavement failure, potholes and cracks are all caused by excess water. The damage may be avoided by building a good drainage system with ditches, culverts, roadways and shoulders.

References

• Tulane University; Streams and Drainage Systems; Stephen A. Nelson; 2003
• FAO Corporate Document Repository: Irrigation Water Management: Introduction to irrigation- Drainage
• Physicalgeography: The Drainage Basin Concept
• "Together with Continuous and Comprehensive Evaluation (CCE) in Social Science"; Rachna Sagar; 2001
• "Sewerage: public health engineering"; Ronald Ernest Bartlett; 1979
• University of Wisconsin: Road drainage