Controlled drainage, commonly referred to as drainage water management, uses a control structure to manage a drainage system’s outlet height. By controlling the outlet height the manager can control the time of year and volume of water that is drained. Restricting flow during the periods when drainage is not necessary reduces the amount of tile transported nutrients by decreasing the volume of water discharged. Increases in crop yield can be realized if water is able to be held back for the time of year when crops operate at a water deficit. Managers should follow a drainage water management plan prepared specifically for their field and drainage system.