The Groote Zeesluis lock in Muiden can withstand many years again

Commissioned by Waterschap Amstel, Gooi en Vecht, water cycle company Waternet recently completed major maintenance of the Groote Zeesluis in the center of Muiden. Dating from 1674, the national monument, which connects the Utrecht Vecht with the IJmeer, contributes greatly to keeping the area's residents dry feet. At the same time, the work of art serves as a striking magnet for residents and visitors to the North Holland fortified town.

To keep the monumental eye-catcher in the heart of Muiden functioning and in top condition, maintenance is of great importance. On a regular basis, but also regularly on a large scale. The latter happened again in the period October 2018 through October of this year. "In close cooperation with several specialized contractors, Waternet, as the implementing organization of Waterschap Amstel, Gooi and Vecht, had the maintenance of the lock complex and bridge carried out in phases," says Hans van der Pal, project manager on behalf of Waternet. "To minimize the inconvenience to local residents and pleasure boats, just about all the work was done during the autumn and winter periods. It is not at all an option to schedule the work in the spring and summer. That is when the complex is very busy. On the one hand because of the many recreational boaters who use the lock intensively, and on the other because of the many visitors who look out from the nearby terraces at this special work of art."

Function

The need for the extensive maintenance of the Groote Zeesluis has everything to do with its important function: ensuring that the hinterland stays dry. "The lock has three chambers: two lock chambers and a sluice chamber," Van der Pal explains. "The latter has been used since its construction to discharge excess water from the Vecht into the former Zuiderzee. For several decades, however, the lock's function has expanded considerably. Because the water in the IJmeer is often higher than in the Vecht during the summer season, the direction of flow is reversed during that part of the year. As a result, the water flows southward from the IJmeer through the Groote Zeesluis towards the river. This is done with the help of two toll valves in the sluice chamber. Much of the water is transported to a number of regional nature reserves, including the Naardermeer and the Spiegelplas near Nederhorst den Berg." 

Miscellaneous

The maintenance work carried out by Waternet and its partners is not only comprehensive, but also diverse. "After the electrical controls for the lock gates and the bridge had already been replaced in the spring of 2019, that fall we began restoring the masonry and painting the various steel structures," Van der Pal looks back. "In addition, the lock gates were renovated. All but two. These were so rotten that they had to be replaced. During the previous winter, all the motion works were renewed. With the end of 2021 in sight, we are currently checking all the technical files. This will be followed by the handover to our client."