This data release includes three sets of data collected for a farm- and field-focused phosphorus reduction study in south-central, Wisconsin, USA. Paired samples collected in the control and treatment watershed analyzed for suspended sediment, total phosphorus, and total dissolved phosphorus during the calibration and post-treatment phases are presented. Samples were collected in fall 2006 through fall 2016. The data sets include: 1) Paired storm event loads parsed into calibration and post-treatment period and by the presence of frozen ground; 2) Paired low flow concentrations; and 3) Daily load data for each watershed separated by total flow and baseflow. These data are interpreted in journal articles to be published in Journal of Soil and Water Conservation and Journal of Water Quality.