A comprehensive dataset is presented that is designed to examine the environmental exposure of surface water pollution by herbicides in an intensively agriculturally used headwater catchment (catchment area 1,032 ha) in Flanders, Belgium. From May 2010 until Dec 2013, stream discharge was measured and water samples were taken at two sampling locations, one at the outlet and one within the catchment. During the 1,325 days the temporal resolution of sampling was at least daily, with subdaily sampling of two or even four samples on 61% of the days. In total 4,350 water samples were analysed for 11 herbicides and one metabolite. Additional meta-information on application practice was collected beginning in autumn 2009 from all farmers working in the study area. Apart from analytical and meta-data we further present links to publicly available spatial data on land use, soils and topography.