No, ginormous battle mechs are not possible in real life. We lack the technology now to make functional, fully operational bipedal machines. Now, once again, I cite the single tower that the Esperantists have made that towers into the sky and houses millions upon millions of human beings. If that could be created in our setting then it is clear something simple as a canal connecting multiple large bodies of water and altering already extant ones to fit a need is as well. We are not the real world, this is not real life, and your comment on newtonian physics is completely unwarranted. This canal is possible. It does not deny physics. It will be expensive. It will be completed unless the admin says otherwise. End of story.