DWM is the process of managing the timing and the amount of water discharged from agricultural drainage systems. DWM is based on the premise that the same drainage intensity is not required at all times during the year. With DWM, both water quality improvement and production benefits are possible. Water quality benefits are derived by minimizing unnecessary tile drainage, reducing the amount of nitrate that leaves farm fields. DWM systems can also retain water in fields that could be used for crop production later in the season.