The Volkerakdam is a secondary dam, which means that the dam was intended to enable other primary dams, such as the Oosterscheldekering , the Brouwersdam and the Haringvlietdam . The Volkerakdam has a connecting and a separating function; on the one hand, the dam connects Noord-Brabant, Goeree-Overflakkee and Hoekse Waard, on the other, the dam separates three waters: the Hollandsch Diep, the Haringvliet and the Volkerak. The dam actually consists of three parts that converge on the Hellegatsplein:
- A dam from Hellegatsplein to Goeree-Overflakkee.
- A dam including a lock from Hellegatsplein to Noord-Brabant.
- A bridge from Hellegatsplein to Hoekse Waard.
Construction of the Volkerakdam started in 1957. The first part of the dam consisted of a closed dam from Goeree to the Hellegatsplaat, which was realized by spraying sand into the closing hole until it was completely closed. No caissons or cable cars were needed here. The second part of the Volkerakdam consisted of a fixed section of dam with a lock that connected the Hellegatsplaat with Noord-Brabant. The permanent section of the dam was closed by means of caissons. The lock ensured that shipping between Rotterdam and Antwerp remained possible. Also, not too much fresh river water from the Maas and Waal was allowed to enter the Zeeland water. The third part of the Volkerakdam was in fact a bridge under which the water of the major rivers theCould flow into Haringvliet . At the spot where the three parts meet, a huge traffic junction was constructed. In 1969 the Volkerak was closed.
The Volkerak locks are Europe’s largest and busiest inland navigation lock complex. This Delta work is of great economic importance for shipping