I do not have the answers as there really is not enough information to suggest much, however I wonder if you could position your site closer to your stream? I say this only because water is so essential to life. Water for consumption, for irrigation, and a micro-hydro power plant perhaps? (I would die for such a location). I wonder if you might be better off in being creative in situating your site next to the stream rather then trying to reroute it?
Now I say all this not being on the ground which is obviously MUCH different.
This is a great series of
video on plumbing streams quite a distance away that may be helpful??? Beware, it is so encouraging it can be addicting to watch!