dams north sea

This is a great narrative, but needs a shot of practical work as well.  For example it far more sensible to extend the northern dam from the northern island along the edge of the shelf all the way to Denmark, thus avoiding the Norwegian trench and leaving the entire Baltic alone.  Depth would be mostly less than one hundred meters  which is something we can do today.  This essentally restores Doggerland by the simple additonal step of closing the English Channel at its shortest reach.

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At the same time it would be possible to build a ship canal all the way from before Calais to the Rhine  which can also take some of that flow.  Simalarly such a canal can be built to londen to carry Thames water. Most important, the whole inflow problem is then reduced to the  Rhine in particular.  Another ship canal can be built to the Baltic to solve all that..  Thus three huge ship canals can divert the bulk of the flow away from the reclamation area.  Those canals can total over five hundred kilometers but only have to face high ground between Hamburg and Lubeck and before Antwerp.
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In that case pumping it out becomes a plausible propostion while also establishing large fresh water lakes as well.  Those will likely be on the Northern side as well with a natural channel taking flood waters for replenishment.  Evaporation may obviate all that as well.


Seen from this light, it is not stupid at all and is actually quite practical.

The dams needs to be my modified earthen dam approach in which sand is pumped into huge retention bags while the water is pumped back out.  This provides an efficient form and the application of natural compaction to even set up a sandstone.  We know that a circular base of one hundred meters can be tapered up to fifty meters while held in a hundred meter long frame at the surface for side to side contact.  It sounds tricky, but I do think that we can actually master all this.

Vibration should maximize compaction for the core in particular and may also allow the application of binding agnents allowing early cementation.  The sand held  outside the core provides stability during the build and possible additonal long term support by natural cementation.