Bart Schultz
Throughout the centuries, until the completion of the Oranje sluices on the Amsterdam side of the North Sea Canal in 1872, these sluices and ship locks played an important role in the discharge of excess water from the collection and transport system of Rijnland to the IJ, and for shipping between Rijnland and the IJ and later the North Sea Canal. The Kolk Sluice of 1290 is the oldest of the four sluices. This is followed by the Kleine Sluice of 1519, the Grote Sluice of 1569, and the Woerdense Sluice of 1611.
The Kolk Sluice owes its name to the fact that it was built at a pool formed by an older dike breach. The Woerdense Sluice owes its name to the fact that it was paid for by the landowners of the area around Woerden, because excess water from this area was eventually discharged at Spaarndam via the watercourses in Rijnland.
Originally, excess water in the area south of the IJ between Santpoort and Amsterdam was discharged via the Spaarne into the IJ, which at the time was in open connection with the Zuider Sea. However, ships had to be towed via a slipway between the Spaarne and the IJ.
In their book Het IJ rond. Geschiedenis van de oude zeedijken rond het IJ tot de opening van het Noordzeekanaal in 1876, Diederik Aten and Paul Schevenhoven describe how, starting from the year 1000, peatlands in the area around the Spaarne and the IJ - which were then still relatively high - were reclaimed. For the area to the South, this effectively also applied to most peatlands behind the dunes. This resulted in land subsidence and changes in the water balance. Among other things, this led to the Spaarne being dammed around 1250 to prevent the intrusion of salty water from the IJ. The Principle Water Authority of Rijnland was also established at that time, as well as the name Spaarndam for the village near the dam.
The Spaarndam was destroyed by a storm surge in 1285 and subsequently restored. The Kolk Sluice was built as a ship lock. In addition to the sluices in Spaarndam, a number of other sluices were also built in the Spaarndammer Dike. The Kolk Sluice became an important link in the inland route from Scandinavia to Flemish cities such as Bruges and Ghent. With the relatively small ships of the time, people preferred to travel inland as much as possible to avoid the dangers of the sea.
The Kolk Sluice is the oldest still-functioning ship lock in Europe. The website of the Stichting Kolksluis Spaarndam - www.stichtingkolksluisspaarndam.nl - states that the Kolk Sluice initially had lifting gates, meaning only small ships could pass through. In 1300, the Kolk Sluice was fitted with horizontal turning lock gates, allowing larger ships to pass through as well.
Initially, the Kolk Sluice was made of wood. In 1571, the wooden lock was replaced by a stone lock, to which renovations were made in 1778 and 1927. The ship lock functioned until 1927 and was taken out of service after the enlargement of the Grote Sluice. In 2009, the ship lock was put back into use for recreational shipping, after which the quay walls and inner gates were replaced in 2021-2022.
More detailed information about the Spaarndam and the sluices can be found on the website of the Principle Water Authority of Rijnland: rijnland.net
