Noordschermerdijk near Rustenburg
Between Rustenburg and Alkmaar, the Omringdijk was formerly known as the Huigendijk. Until four hundred years ago, the dike was surrounded by water on both sides: the Heerhugowaard and the Schermer were still lakes at that time. They were drained during the Golden Age. These windmills were built as part of the drainage of the Heerhugowaard.
Although the water sometimes led to dangerous situations, the lakes also had a useful purpose: water was discharged through sluices in the dike. With the reclamation of Heerhugowaard between 1629 and 1631, an important drainage point was lost. From then on, the excess water was drained into a ring ditch. To maintain the water level, the land reclamation engineers of Heerhugowaard built these mills. The mill in the foreground lost its sail cross in 1919 and was demolished in 1936.
The mills (red dots on the map) pumped the water from the ring ditch into a mill pond. This pond emptied into the Schermerringvaart canal at Rustenburg (arrow). The water level in the ring canal was higher than that in the Heerhugowaard ring ditch. This meant that direct flow was not possible. In 1941, the water levels were equalized. The separation between the ring ditch and the millpond was removed and the mills lost their function.
Until the eighteenth century, many water mills used a paddle wheel, whether they were draining 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 pumped higher. That came in handy, because a polder such as Heerhugowaard lies almost three metre the level of the drainage point, the ring ditch.
The mill pond became overgrown after 1941, as can be seen in the photo. In 2010, Landschap Noord-Holland had it excavated. The mills will be restored to working order in the coming years.
De Schermer (right) lies quite low: between three and four metre sea level. The water level in the ring ditch and the mill pond is three metre . Such differences demonstrate the importance of a stable dike and a reliable water network.
The water board recently reinforced the Noordschermerdijk. Where necessary, the inner slope was made less steep and the support berm was extended and raised. This should make the dike more resistant to heavy rainfall, extreme drought, and prolonged high water levels in the ring ditch. In its previous state, it could have shifted inward under such conditions.
When reinforcing a dike, the water board has to take all kinds of things into account: local residents go to school or work in the morning and come home in the afternoon. There are cables and pipes in the dike. It is also important to disturb the flora and fauna as little as possible and to respect the historical appearance of the dike.