Types of Drainage
1. Surface drainage
2. Sub-surface drainage
Process of removing the excess water from the land surface is known as surface drainage.
Sub- surface Drainage:
If the excess of water does saturate the pore space of the soil, the process of its removal by down ward flow through the soil is known as Sub-surface drainage or Internal Drainage.
There are two type of Sub-surface Drainage:
1) Horizontal Drainage
2) Vertical Drainage