The Limnodata Neerlandica data set contains the data of more than 30 years systematic and project based sampling of Dutch, mainly freshwater, waterbodies. Data originate from 37 data providers; 26 water boards, the provinces and the Ministry of Transport, Public Works and Water Management. Over 20,000 sample points were used. The main purpose of the dataset is monitoring the quality of Dutch surface waters. Next to the biological characteristics also a-biotic data were sampled and stored alongside the biotic data. Observations are available from phytoplankton, diatoms, aquatic and riparian plants, macro-invertebrates and fish. The data were collected on a yearly base. The taxonomy has been validated according to the Dutch standardised checklist of aquatic species. Update January 2015: Added data for 2011 and 2012. Enhanced taxonomic and locality data fields.