> Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be

> Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be a quite manageable maximum salinity. First of all, this is not what the OP is suggesting. OP is using pipelines and wants to generate electricity from the potential energy. And for good reasons: between the suggested Qattara sea and the Med, there sits El Diffa square in the way. Which is 200m above sea level. You could tunnel that with a pipeline. Trenching that for a channel would be quite the project. Secondly, the Med only has a tidal range of 50cm. Using that to move a significant amount of water along a 100+km canal needs a truly humongous channel cross section. OP suggests using electricity to desalinate his sea. This would take insane amounts of energy, creating freshwater from desalination at the rate its evaporating across thousands of square kilometers in the Sahara takes orders of magnitude more power than the power station is going to generate. He also suggests using salt extraction pools. This only work, if rainfall creates fresh water rivers feeding his sea. Otherwise the water evaporating from this pool is lost to the sea, meaning you can only ever (at best) keep the salinity constant, but never decrease it. I think it's best to face it from the beginning: we're creating another Dead Sea. Salinity will prohibit life in the water and directly at the shore. Rainfall might make it possible away from the shoreline. But there will be absolutely no algae, shrimp or flamingos.