The Petersburg dam is a complex of hydraulic structures, stretching across the Gulf of Finland from south to north, from the Bronka station in the Lomonosov area to the Gorskaya station in the Sestroretsk area via Kotlin Island.
Petersburg floods occur because of the surge of waves generated by cyclones in the area of Iceland, where the warm Gulf Stream is encountered by the cold waters of the Arctic. The ocean swells, and a strong westerly wind begins to drive this wave toward the Baltic Sea. When entering the narrow and shallow Gulf of Finland, the wave tends to intensify and, if it does not encounter obstacles in its path, it hits Petersburg.
The most powerful floods in our city occurred on September 21, 1777, November 7, 1824, September 23, 1924, October 15, 1955 and September 29, 1975.
Construction of the complex, designed to protect the city from devastating floods, began in 1979. On August 12, 2011, the St. Petersburg dam was opened. The total length of the dam was 23.4 km.
The complex includes 6 culverts and 2 navigation systems. Cultivators are needed to release the waters of the Neva into the Gulf of Finland, allow the fish to make habitual migration and preserve the ecology of the area. They have culvert spans through which road bridges are laid.
Ship passages, as their name implies, are intended for the passage of ships. Each of them includes an adjustable bridge and bolt. An underground automobile tunnel with a total length of 1961 m passes under the main navigable canal. The lowest point of the tunnel is located at a depth of 28 m.
With the threat of flooding all the dam shutters are closed. In this state, the sea gates of St. Petersburg on a solid lock and are ready to meet with the water.
The section of the Ring Road leading from St. Petersburg to Kronstadt passes through the dam. Scenic views of the Gulf of Finland, the city of Kronstadt and its forts are opening from the road.