This data set is part of the data collected by the author to support his research work. The data matrix consists of a set of data taken for physicochemical variables measured in water and soil. There were three matrices in which these properties were measured: water from the water table, surface water from a stream, and soil that was part of the areas near the stream. These data were taken in La Nitrera nature reserve in the municipality of Concordia, department of Antioquia, Colombia. The main objective of the study for which the data were taken was to describe the influence of the slope on nitrate flow through the subsoil. To do this, measurements of nitrate concentrations were taken at three sampling stations with different slopes and at different times. Measurements of different properties were also taken to describe the possible influence of other properties on the behavior of nitrates.