But that’s a polder made mostly by building dykes and draining the land rather than raising up the ground level across 970 square km. Flevopolder is about 4m be

But that’s a polder made mostly by building dykes and draining the land rather than raising up the ground level across 970 square km. Flevopolder is about 4m below sea level. I think the plan here is different and will not be done by building up dykes and draining the area inside.