North and South Locks, Schardam

In the village of Schardam, there are two old locks in the former Zeedijk, the Noorder and Zuidersluis. The Schermerboezem, the large water storage area in the heart of North Holland, drains into the Markermeer there, and there have been locks at this location since the 14th century.

Around the year 1300, there were a number of rapidly growing lakes between Alkmaar, Hoorn, and Monnikendam. They were connected to the Zuiderzee via various waterways, such as the Korsloot, which connected the Beemstermeer to the sea. The land was low-lying and vulnerable to erosion and flooding. It became increasingly difficult to keep the Zuiderzee water out. That is why the Korsloot was dammed at the beginning of the 14th century. As early as 1320, there are references to Schardam, a village that sprang up near the dam.

Initially, there was an opening in the dam for drainage and shipping purposes, but this was not a satisfactory solution. In 1357, Count William V authorisation two wooden sluice gates in the dam, which made it easier to control the flow of water. From then on, it was possible to drain water at low tide, for example, and prevent seawater from entering the land at high tide. A series of villages in the hinterland were responsible for building the sluices. One disadvantage was that it was no longer possible to sail through.

Of these two locks, the Noordersluis was located on the border between the banne Hoorn and the territory of the Lord of Oosthuizen. Ban is an old name for a jurisdiction. These boundaries hardly changed for centuries. That is why, in 1761, Hoorn erected a beautiful ban post on the lock, which still exists today, topped with a unicorn holding the city coat of arms between its front legs. Anyone who had been banished from the city of Hoorn was not allowed to go any further. The ban pole was restored in 2024 after thorough color research. The brown tint of its body has been replaced by the original red color. This color corresponds to the official city coat of arms of Hoorn.

In the 16th century, it became necessary to better protect the wet heart of North Holland. In 1544, Emperor Charles V (1500-1558) decreed that the last two open sea gates at Edam and Krommenie had to be closed. Nothing came of this until 1565, when a board of dike reeves and water board members was appointed to do the job. This laid the foundation for the Water Board of the Drainage Sluices in Kennemerland and West Friesland. This new water board took over the management of the sluices. Its coat of arms featured the double-headed imperial eagle standing on top of a sluice, as can still be seen on a coat of arms stone embedded in the Noordersluis.

Between 1589 and 1595, Uitwaterende Sluizen renovated the outdated locks in Schardam, first the Noordersluis and later the Zuidersluis. The wood was replaced by stone. Willem Jans Benningh (c.1570-1636) from Alkmaar, one of the most renowned lock builders of his time, was involved in this project . A commemorative stone was placed in the Zuidersluis: 'To prevent the violence of the inland waters, I, Dickgraef and Heemraeden, have placed this here'. Presumably, a year stone was also added at that time, the stone with the inscription 'anno'. The decoration on this stone is clearly 16th-century. There was probably also a stone with the year of completion of the lock.

The Noordersluis had already shown defects during construction, and after more than a century, a new lock had to be built, which was completed in 1712. This lock was also provided with a commemorative stone, an oval stone bearing the name of the water board and the year. The decorative border around it bears the name of jonkheer Gerard van Egmond van de Nijenburg (1646-1712), in memory of this Alkmaar nobleman who was dike reeve of Uitwaterende Sluizen for thirty years. His family played an important role in the administration of various North Holland water boards for a long time.

In 1737, it became apparent that the pilings of the port of Schardam had fallen prey to the shipworm, a boring mussel that was spreading rapidly in those years. At the time, the dikes were reinforced with beams and piles, and the shipworm completely destroyed all that wood. In addition, the locks were leaking more and more – it was suspected that this was due to the Zuidersluis, as the Noordersluis had been renovated not long before. It was decided to dam up the lock and drain it, and then it turned out that the shipworm had also ravaged the Zuidersluis. 

The Zuidersluis lock was completely renovated: the walls were also in such poor condition that they had to be replaced, although some materials were reused. It took over a year before the lock was working properly again. The 16th-century date stone was reused, but a new date stone was placed on the other side of the lock. This stone clearly has 18th-century decoration.

The 18th-century locks proved to be very durable, although some changes were made later on. After the flood disaster of 1916, the Zuiderzee dikes were raised; the Schardam locks were also made higher at that time. Recently, the monumental locks were fitted with new sluice gates, allowing for better control of the inflow and outflow of water. However, the iron fencing on the lock bridges is probably still 18th-century; and to the north of the locks stands Schardam 21, a national monument that was once the lock keeper's house.

In 2021-2022, both locks were modified with a new slide consisting of two parts. This allows the locks to be partially or completely closed. As a result, the locks can hold back high water when the situation requires it. At the same time, the function of letting water in or out is retained.

Extra

• The locks of Schardam are located on the walking route of the third stage of the Zuiderzeepad.  
• Those who cycle the Zuiderzee Route will also pass through the locks on the Amsterdam-Hoorn section.