Selecting the Drainage Method for Agricultural Land

To facilitate crop growth excess watershould be drained from the rooting zone toallow root development of the crop and fromthe soil surface to facilitate access tothe field. Basically, there are threedrainage methods from which the designercan select being; surface drains, pumpedtube wells and horizontal pipe drains.The selection between these techniques isnot very straightforward and depends to acertain extend on the preferences of thedesigner. Yet, guidance is given in thispaper on the basis of a set of questionsthat are grouped in a flowchart.Although the flowchart suggests sharpchoices between alternative drainagemethods, in reality the choice between therecommended methods overlaps. Partly thisis because the values in the selectioncriteria (questions) are indicative.Further overlap is caused by theconstruction and operation & maintenancecost of the drainage system under localconditions. These costs are not included inthe flowchart.