Frequently asked questions webinar Noordkop

On June 24, 2024, we hosted an informative webinar. Below are the most frequently asked questions and corresponding answers.

Why is the design of the salt barrier, an essential part of this project, not yet known?

The form and effectiveness of the salt barrier in the Spuikanaal is still being studied. When the construction of the Oostoever pumping station starts it will also be known whether and what the salt barrier will look like. There will then be sufficient time to build and deliver it before the Oostoever pumping station is put into operation.

Is the salt barrier necessary under normal conditions to stop the salt tongue?

The salt barrier is an emergency measure, which under normal conditions is not necessary to stop the salt tongue. Under normal conditions, the salt tongue is stopped by the automated water management system (monitoring and control) that controls the sluice, the pumping station and the fish passage. With this system, the amount of sea water to be released can be controlled by partially or completely closing the East Bank fish passage. In addition, by means of sluicing with the Oostoever lock, the salt tongue can be reduced. Finally, if these measures have insufficient effect or are not possible, the Oostoever pumping station can be put into operation.

Are all pumping stations, which grind on the Amstel Lake watershed, fish passable?

The policy of the State Water Board requires that all new pumping stations be fish-friendly. This means fish passage, or pumps must be fish-friendly passages. A fish-friendly pump is made so that fish can swim through the pump without injury while pumping water. 

Does this project play a role in current climate change developments?

Besides improving fish migration, the measures, and the pumping station in particular, simultaneously ensure that the Amstelmeerboezem is prepared for the expected sea level rise and climate developments. Due to climate change and sea level rise, it will become increasingly difficult to regulate the water level of the Amstelmeerboezem in a natural way (drainage). Therefore, according to the current climate scenarios, within the next 50 years a pumping station will also be needed to regulate the water level of the Amstelmeer basin. However, the climate scenarios are becoming more topical, so the Oostoever pumping station may have to be used sooner for water control. In addition to flooding, the package of measures also prevents salinization. With a pumping station, the chance of having to incidentally drain relatively brackish water from the Balgzand Canal into the fresher Schermerboezem, when insufficient water can be drained through the sluice (as, for example, in the autumn of 2023), will also decrease. The automated water management system also gives better control possibilities, so that (fresh) water can be used more economically.

When did the North Head Wet Infrastructure Improvement Project succeed? 

It takes several years before conclusions can be drawn about the effect of the various measures on fish stocks and the various target species. Therefore, after construction, monitoring (research) of fish stocks and target species will take place. The target species for this project are eel (glass eel) and three-spined stickleback. In addition, other species living in fresh and salt water can also use these facilities. 

Do the islets in Amstel Lake refer to the hafs that were recently restored?

Yes, that's right. The original islets were subsided and washed away by wind and water. By placing boulders on the former islets, hafjes have been created in which fish spawn and grow. Due to the defense with boulders, the hafjes will silt up over time, creating refuge areas for birds.