Strong(er) together

VOBI Infra and Gebr. Beentjes GWW b.v. are essentially the same kind of contractors and also do the same kind of work. Reason enough for both contractors to jointly tender for the new De Poel pumping station. And with success. In December 2019, Aannemingscombinatie De Poel was awarded the project. After an intensive period of construction, the new pumping station, which regulates the water level in the Waterland basin, was festively opened on April 13. A review with Bastiaan Blok, project manager on behalf of Aannemingscombinatie De Poel.

Of course we celebrated winning the tender by eating cake together with HHNK during the first conversation about this work. And then it became 2020, Blok begins. "After just one physical progress meeting, the corona crisis broke out, we went into lockdown and everyone sat at home. The distance from the client suddenly became a lot greater. Not ideal in the start-up phase of a UAV-gc project. But then it turns out that we people are very flexible after all and know how to adapt quickly to the new situation."

Water safety

The new pumping station will replace the old De Poel pumping station. "The old pumping station was at the end of its useful life and had many defects," Blok said. "A conscious decision was made to build the new pumping station at a different location, a little further down the dike. A place with more space. And that is not only pleasant for realization, but also for maintenance." The entire structure is raised from concrete and built in a number of building pits below the water table. "By choosing a cofferdam with steel sheet pile walls, we immediately take over the function of the dike and water safety is guaranteed at all times. The pumping station is founded on precast concrete piles and built in phases, particularly because the N518 traverses the project, the only connecting road to the island of Marken. It also proved most efficient in terms of time to complete the work."

Two construction sites

Contractor combination De Poel started by rerouting the N518 to build the inflow side. "This side was the most labor-intensive part in terms of concrete structures, mechanical installations, the pumps and all the electrical installations to control the pumping station," Blok clarified. "The moment the concrete work and the first part of both (precast) press shafts were completed, we moved the N518 back to its original position to build the outflow side. In parallel, we were finishing work on the inflow side. So for a whole period we were working on two construction sites at the same time. That did require coordination, because even though this spot in the dike had the most space available, it was still quite limited for work of this magnitude." Blok compares it to building in inner-city areas. 

Best for project

Before and during the realization of the pumping station, much attention was paid to phasing and logistics. "Reason enough to appoint our own environmental manager for good coordination with all direct stakeholders, but also with, for example, the bus company, emergency and emergency services. Furthermore, we worked with speed limits, half lane closures and with many temporary traffic stops to minimize disruption." Blok looks back on a pleasant cooperation with all partners and in particular with the Hollands Noorderkwartier Water Board. "We faced challenges together and in good consultation, always opting for a 'best for project' solution. We sometimes experience that differently. The result is accordingly."