Managing nitrogen (N) and phosphorus (P) loss from drainage ditches requires an understanding of the factors affecting N and P transport to and through the ditches. Large loads of N and P have been observed in drainage ditch effluent (20 kg/ha for N and >25 kg/ha for P) from the University of Minnesota Southwest Research and Outreach Center. The objective of this ongoing study is to compare the impact of drainage flow control on in-stream N and P losses from paired ditches with and without flow control. In this presentation we describe process occurring within the ditch system, the process controls, relevance to off-site impacts, and ditch management and N and P transport.