Eutrophication phenomena in reservoirs. If in the last few decades eutrophication represented an isolated incident affecting only some small lakes, now, dam projects have the potential to change the flow of nutrients and energy flow in river systems. Often, they provide ideal conditions for algal blooms, leading to eutrophication of the lake.In this paper, the authors aim to provide the mass trophicity level assessment of water in the Solesti lake, other issues and mitigation of eutrophication.