Abstract
In the modern world, increasing importance is attached to the formation and preservation of surface water quality, which is recognized as one of the leading factors in maintaining human health and well-being. In the 2000s the water quality in the Khoper river was considered as one of the best in Europe, but now the waters have become more polluted, and flow regulation (even with a low-pressure dam) may cause declension of their condition due to disruption of the water exchange process. The aim of the study was to evaluate the river flow regulation effect on the floristic diversity of vascular aquatic plants and the water quality in the vicinity of the Potlovskaya Dam near the source of the Khoper River (Penza region, Russia). The content of nutrients in water was estimated since their concentration and ratio determine the trophic status, water quality, and the state of aquatic vegetation, which is important in assessing the status of the environment of a particular region. Water chemistry and plants were sampled at two sites, one being upstream of the Dam, the other one being downstream. We have found that flow regulation by this small hydraulic installation causes some changes in the hydrochemical regime but does not affect the floristic diversity.