Design the application facilities. Determine (1) the amount of water that must be applied in a normal irrigation, (2) the time allowed for applying it and (3) the rate at which it can be applied. Then determine the amount of water that must be delivered to field. Plan for land leveling if it is needed. Locate and design the head ditch or pipe line to fit the method of irrigation used. Locate and design ditches, pipes, levees and the other structures needed to apply water to field in the amount and rate required by the crop and soil.
Plan the delivery facilities so that they permit delivery of water to the different fields in the volume and rate required by the method of application-previously selected. Select and design the method of conveyance either ditch or pipe line. Locate and design all the necessary grade control or distribution-control structures, including measuring devices.
Plan for the disposal of any irrigation wastewater and excess rainfall promptly and safely. Consider recovery of wastewater for reuse. Include all necessary disposal facilities-channels, pipe lines, tiles, structures and pumps.