The paper deals with environmental impact assessment of the proposed Sereď − Hlohovec water-works, and describes the endeavour at the design, management and conduction of impact assessment. The water-works will be located in the inundation area of Váh river, in the section beginning by the Kráľová water-works impound (Sereď) and ending by the outlet canal of the Madunice power plant (Hlohovec). The entire construction has a line character and the individual objects are located in a 24 kilometers long line in North-South direction. The utilization and quantification of the extent depend on the technical variant of the water works.