Some issues in the assessment of eutrophication of river waters as a consequence of the construction of a storage reservoir (on the example of the Bystrzyca River)

The quality and its changes of the Bystrzyca River waters, related to the operation of the reservoir in Zemborzyce (Lublin area), were analysed. In the years 2005–2007, the following eutrophication indicators were analysed in the Bystrzyca River: total nitrogen, total phosphorus, nitrate, and chlorophyll a content. In accordance with the flowing waters criteria of the Polish law, the river waters did not show susceptibility to eutrophication or showed advanced water eutrophication. In the case of the criteria applicable to stagnant waters, the river waters showed high eutrophic potential. When constructing a reservoir on a river, water trophic potential based on the standing water criteria should be taken into account.