Drains can be classified in several ways. Drains on flat land have similar drainage effects on either side of the drain and are called relief drains. Drains on sloping land intercept seepage water moving down hillsides and therefore have most effect on the downslope side. They are called interceptor drains.
Drains can also be classified as being open drains (that is, open at the ground surface) or buried drains (for example, tube drains)
