### Model of the fourth stage

Here, we consider the last stage of the construction. This stage represents the whole construction of three parking silos that reach the last Neogene layer and a large underground parking garage with entrances that are under almost the entire area of the square. Moreover, further underground objects were added to the lowermost side of the square. These objects are gray in the picture. The newly designed protection wall, along with an existing barrier of the West Theatre, cause an elevation of the groundwater level. This is also caused by a recharge of groundwater from the Neogene subsoil of the side barriers. The elevation of the groundwater level after the fourth stage can be clearly seen on the contours of change in the groundwater level's. The maximal elevation of the groundwater level is 4 m, even reaching the sides. On the NE side of the model there is an elevation of 0.5 m. In the wake of any building in the fourth stage, there is a decrease in the groundwater level of 1 m. The elevation in the fourth stage is significant enough to require remediation.