The french tried that and failed, the biggest problem is that there are mountains in the way, and instead of cutting through them, it is easier to just make locks over them. (A more minor concern is that there will be ecological interchange between the 2 bodies of water, allowing potentially invasive species to go across)
+Bruce K Assuming the highest level has a natural source then simply letting it flood... otherwise it'd have to be pumped into the channel from up high in the channel I suppose.
From the lake that feeds the lock. The lake is fed by rivers and streams, and if the canal wasn't taking water would eventually overflow the locks and spill into the ocean. (I'm sure there are spillways to prevent just such an occurrence.)
Lukas Krause No! I was talking about the oceans of the world all being connected. I would imagine that all ocean water is at the same height. Am I wrong?
+Barry Sabahat You are right, but to get across the high mountains of Panama, they use a man-made lake at the top, and lock their way up, then back down to go over the land mass.
I must be dumb... why not shape the canal below to accomodate and ground clearance (a progressive slope) and let the water level itself out? I do not understand!
They call that a "river." And it's not always practical, when there's a large elevation distance. Either the current would be too fast for ships to move upstream, or the lake would empty all of its water down the river, kind of defeating the purpose of moving shipping into the lake in the first place.
