Neva Bay
Historically, storm surges from the gulf have caused over 300 floods of varying severity within the city, some with devastating effects. The dam has the capability to protect the city from water rising up to . Its first use to hold back the incoming Baltic water into Neva Bay on 28 November 2011 resulted in a water rise of 1.3 meters above sea level (masl), below the flood level of 1.6 masl according to the Baltic system of coordinates. This prevented what would have been the 309th flood in the recorded history of the city, saving some 1.3 billion roubles of projected damage.