Agriculture drainage is mainly of two types.. (1). Surface drainage (2). Sub Surface Drainage. However there are some other drainage systems also. Figure 1 classifies the various types of drainage systems. It shows the field (or internal) and the main (or external) systems.[1]
The function of the field drainage system is to control the water table, whereas the function of the main drainage system is to collect, transport, and dispose of the water through an outfall or outlet. In some instances one makes an additional distinction between collector and main drainage systems.
Field drainage systems are differentiated in surface and subsurface field drainage systems.