Oosterpolder pumping station
The Oosterpolder pumping station is located at the intersection of Holenweg and Schellinkhouterdijk in Hoorn. The pumping station ensures that excess water from the former Oosterpolder area is discharged into the Markermeer via outflow pipes.
Eastern Polder
Since 1483, water from the Oosterpolder, consisting of the districts of Hoorn (west side), Zwaag (north side), and Westerblokker (east side), has been pumped to the Markermeer (then still called the Zuiderzee) in the vicinity of the Oosterpolder pumping station. Until 1873, this was done using three screw pumps: the Middelste or Kleine Molen, the Laanmolen, and the Dijkmolen.
In 1873, the Oosterpolder Water Board commissioned the construction of a steam pumping station on the site of the Middelste mill. The three mills were then demolished. The steam pumping station was designed by the engineering firm W.C. and K. de Wit, which built a large number of steam pumping stations in North Holland. The new pumping station had a capacity of 110 cubic metre per minute.
New pumping station
In 1953, the steam pumping station was replaced by the current electric pumping station Oosterpolder, commissioned by the Oosterpolder Water Board in Drechterland. This pumping station is located on the site of the Dijkmolen. The old steam pumping station with its chimney was then demolished. The new pumping station was designed in a traditionalist style by the Technical Advisory Bureau of the Union of Water Boards (Tauw). Buildings in this style are sober and unadorned. Typical of this movement is the use of brick and wood and the application of sloping roofs.
Marshall Plan
Two Worthington centrifugal pumps were installed in the pumping station. This type of pump was shipped in large numbers from the US to the Netherlands after World War II as part of the Marshall Aid program. Both had previously been used in Zeeland. They each have a capacity of 65 cubic metre minute at a delivery head of 3.5 metre.
Surroundings
The pumping station includes a service residence and storage facility built at the same time in post-war reconstruction architecture. In 1975, the West Friesland Water Board had a second polder pumping station built next to the existing one. This diesel pumping station has a single pump with a capacity of 130 cubic meters per minute and was necessary due to the urban expansion of Hoorn. All pumps are automated.
As part of the dyke reinforcement between Hoorn and Enkhuizen, the outlet pipes of the pumping station through the West-Friese Omringdijk were extended in 2009. In that year, the municipality of Hoorn also purchased the official residence for demolition to make way for a new roundabout at the Willemsweg-Holenweg intersection. The duckweed fence at the rear was automated in 2021.
Renovation
The diesel engine from 1975 remained in service until 2021. It was then replaced by an electric motor, the last diesel engine used by the water board. The pump has also been replaced and now has a capacity of 190 cubic meters per minute.
In 2023, the front pump in the 1953 pumping station will be replaced (replacing both pumps) with a new one with a capacity of 130 cubic meters per minute. The pump is being replaced because parts for it are becoming increasingly difficult to obtain. The rear pump will remain intact but will be taken out of service and will only be used during demonstrations.