The Hydraulic Project Włocławek was commissioned in 1970 as the first barrage of the Lower Vistula Cascade (LVC). The purpose of the LVC was to create an important source of hydro-energy and inland navigation route connecting central Poland with the port city of Gdańsk. Along the Lower Vistula (LV) important cities and industrial centres are located. The Włocławek project still remains the only barrage on the LV thus creating a number of problems. The paper presents the basic hydrological and hydraulic data for the Vistula river, and describes the Włocławek project, hydraulic model investigations conducted in the design phase, the construction of the project and the main problems, attendant on its use, including the winter flood of 1982 in the upper part of the Włocławek reservoir. The paper ends with conclusions on project construction and exploitation. The next barrage downstream from Włocławek is proposed.