Noordschermerdijk at Rustenburg
Between Rustenburg and Alkmaar, the Omringdijk used to be called Huigendijk. Until four hundred years ago, the dike stood in water on both sides: the Heerhugowaard and the Schermer were then still lakes. They were drained in the Golden Age. These mills were built as part of the reclamation of the Heerhugowaard.
Although the water sometimes led to dangerous situations, the lakes were also useful: water was discharged into them via sluices in the dike. With the drainage of the Heerhugowaard between 1629 and 1631, an important drainage point was lost. The excess water was now drained into a ring ditch. In order to keep it at the right level, the Heerhugowaard reclaimers built these windmills. The mill in the foreground had lost its sails in 1919 and was demolished in 1936.
The mills (red dots on the Map) ground the water from the ring ditch into a mill pit. It flowed into the Schermerringvaart at Rustenburg (arrow). The level in the ring canal was higher than that in the Heerhugowaard ring canal. A direct flow was therefore not possible. In 1941 the levels were equalized. The separation between ring canal and gully was undone and the mills lost their function.
Until the eighteenth century, many watermills milled with a scoop wheel, whether they were milling a polder or, as here at Rustenburg, a ring ditch. The wheel was eventually replaced by a spiral screw, the screw pump. This allowed the water to be raised higher. That came in handy, because a polder like the Heerhugowaard is almost three meters below the level of the discharge point, the ring ditch.
The mill pit grew closed after 1941, as shown in the photo. In 2010, Landschap Noord-Holland had it dug out. The mills will be made millable again in the coming years.
The Schermer (right) is quite low: between three and four meters below NAP. The level in the ring ditch and the mill pit is three meters higher. Such differences show the importance of a stable dike and a sound water network.
The high water board recently reinforced the Noordschermerdijk. Where necessary, the inner slope has been made flatter and the support verge has been extended and raised. This should make the dike more resistant to intensive rainfall, extreme drought and prolonged high water levels in the ring ditch. In its old state, it could have slid inward under such conditions.
When reinforcing a dike, the Water Board has to take all sorts of things into account: residents go to school or work in the morning and come home in the afternoon. There are cables and pipes in the dike. In addition, it is important to disturb flora and fauna as little as possible and to respect the historical appearance of the dike.