​Heavy rain has caused severe flooding on the Acropolis since, at least, 2013. The surface of the archaeological site and the rocky ground have very low absorbency. After the first damages, the first preliminary plans to resolve the problem were approved by the Central Archaeological Council in December 2014. Unfortunately, these were not implemented.

In 2018 there were heavy rains that affected the walls, especially in the northern slope. In fact, at that time, the northern promenade of the Acropolis was closed for a long time.

The first hydraulic drainage project was carried out -for the first time- in 2020, on the east and south side of the Parthenon. Yesterday's rainfall did not cause any problems. The hydraulic project is continuing to stop permanently the phenomenon on the rock of Acropolis, reducing the risk of flooding the residential area of Plaka.