This document summarizes tile drainage research from three farms in eastern Wisconsin. The key findings are: 1) Tile drains can flow year-round, including during frozen conditions, and may transport similar or greater volumes of water compared to surface flows. 2) Tile drains were responsible for transporting 16-24% of total precipitation on the farms as drainage, compared to 6-10% for surface runoff. 3) The majority of nitrogen (43-94%) and a significant portion of phosphorus (46-77%) and sediment (22-37%) left the fields through tile drains rather than surface runoff. 4) Proper manure and fertilizer management is important