The Water Framework Directive (WFD) introduced the obligation to monitor hydromorphological elements of rivers, including hydrological regime, river continuity, and riverbed morphology. It is estimated that by the year 2015 all uniform water bodies in the EU will be ensured at least very good (class I) or good (class II) ecological status plus good ecological potential. European standards define requirements concerning slightly different quality indices as well as methods of their assessment in such studies.
In Poland, hydrological valuation has been realized since the early 1990s using different research methods. Within the framework of appraisals applied at that time, the requirements of the WFD, adopted later, were not always considered. This paper presents results of an analysis conducted on the basis of the findings of all studies of the hydromorphological status of Polish rivers conducted and published in 1995-2008. From 2,202 km of watercourses, in which scoring was applied for selected quality elements, a total of 1,588 km, uniform in terms of methodology, were selected from 35 rivers. Statistical analysis determined the distribution of results for analyzed quality elements, constituting the foundation for a new method of hydromorphological monitoring of rivers, adapted to the requirements of the WFD. Moreover, our paper also presents a review of developed research methods for the hydrological valuation of watercourses, applied in Poland and Europe.