For the assessment of water status, the biological quality component macrophytes and phytobenthos must be recorded at representative river measuring points. According to the Thuringian Monitoring Framework Concept, a total of 366 samples are to be carried out in the period from 2023 to 2025, with about one third of the sampling being carried out annually. The service includes independent sampling, processing of samples and identification of species in the laboratory as well as digital data acquisition.

Since 2006, the monitoring of surface waters with regard to their ecological status has been realigned in accordance with the requirements of the Water Framework Directive (2000/60/EC). The Ordinance on the Protection of Surface Waters (OGewV) of 20 June 2016 transposes the detailed regulations on water monitoring into national law. The express mandate for the monitoring and determination of the status of water bodies by a competent authority results from § 9 para. 2 in conjunction with Annexes 9 and 10 OGewV. According to § 60 para. 1 ThürWG of 08 June 2019, the competent technical authority is the TLUBN. The respective status of the waters is measured and determined by the investigation and evaluation of the biological quality components macrozoobenthos, macrophytes/phytobenthos, fish and phytoplankton.