The institute's large test hall is divided vertically. The test area on the ground floor, measuring around 1,100 m², has a large usable length of 60 meters, allowing the undistorted representation of systems on large rivers (e.g. the Danube), including the necessary connecting sections. A so-called giant staircase connects this low-pressure area with the smaller medium-pressure area, which is 9 meters lower and is reserved for full and partial models with greater heights.

An elevated tank with a usable capacity of 70 m³ that supplies both laboratory areas ensures a maximum stationary pressure head of 15 meters, thus enabling the performance of those tests that, due to their relationship to the Reynolds number, require large amounts of water and constant pressure heads. The staircase-like connection between the two laboratory areas is used to build special models.

The core of the test water system is a central pumping station, which consists of four staggered units and achieves a delivery rate of up to 1000 l/s. All pumps pump into the elevated tank via a collecting line and two risers. A spill length of almost 100 meters ensures sufficient water level stability even under strongly fluctuating operating conditions. Of course, the models can also be controlled directly by the speed-controlled pumps.