The aim of study The aim of study was to determine, how the pool fish pass located on the Dłubnia River operates and to formulate recommendations, due to which it will work effectively and will not be an obstacle for migrating fish. Materials and methods Field work. Identification of elements of fish pass that may restrict fish migration on the grounds of standard geometrical dimensions. An attempt to design its repair. Results and conclusions The fish pass does not operate effectively. The paper presents recommendations for its improvement.