Considerations for the design of intercepting drainage for collecting water from seep areas

Springs that appear at multiple sites on sloping lands and create problems of excess soil moisture and reduced crop yield require the implementation of a network of intercepting drains. The water removed by the intercepting drains also needs to be conducted to a collecting shaft or main drain, whereby it can be safely utilized or discharged back to a lower-lying position in the landscape. In this paper, we present a design method for establishing the position of the first row of interceptor drains and the number of successive rows of intercepting drains, as well as the distances between them. The first row of intercepting drains must be placed upstream of the upper limit of the wet area, through those points at which water-bearing material is found at 40-50 cm underground. The number of rows of necessary intercepting drains is determined from the ratio between the thickness of water-bearing material and the thickness of the filter+drain. For multiple springs that are concentrated on the surface of sloping lands, we propose the solution of a collecting chamber with a side drain and bottom filter.