The Racibórz Dolny reservoir has an area of 26.3 km² and will hold 185 million cubic meters of water, which is as much as would fit in 226 Palaces of Culture. The volume of the facility will gradually increase to 300 million m³, due to the aggregate extracted from the basin.

The installation has been designed as a reservoir, i.e. a dry basin that will be filled only in the event of flooding. When the high water arrives, the reservoir will dam up the water, securing an area of about 600 km² from Racibórz through Kędzierzyn-Koźle, Brzeg, Opole, Oława, to Wrocław. The investment will protect nearly 2.5 million residents in three voivodeships: Silesian, Opolskie and Lower Silesian. The spillway structure is equipped with six main valves, the operation of which will be mechanical and automatic.

The Racibórz Dolny reservoir is the largest hydrotechnical investment in Poland. More than 6.8 million tons of soil were used for the construction, which is an equivalent of a total of 130,960 freight wagons.