This post is in the front page of HN because of this initial confusion. Otherwise that was no larger deal compared to other projects that are going on around the world.
What's the confusion here? The site makes pretty clear it's about an engineering project, doesn't it?
And there's plenty of cool about this project, from the reusable kingsize lego-like blocks used to strengthen the dike, to the meandering river for fish passing throuh the dike. There's also a VR video.
The passage for fish is highly needed. Eels are almost extinct in the Netherlands. The adults are inside the country in sweet water, but they cannot get out due to sluices and pump stations. They get slaughtered there.
They need to get out to sea to make a journey to make offspring. That offspring sometimes gets caught in France on the way back, where it is grown and sold in the Netherlands. Fishing results from IJsselmeer can also be found in shops but they are not easy to catch anymore. I would think, for statistic reasons, the caught eels in France might be more sustainable than catching grown eels in the IJsselmeer. The real solution is to work out better sluices and pump stations, so fish can pass again.
