Mesh orientation error


I need to create a 3D mesh of a dam. I had no problem except one, the dam isn’t horizontal, it’s slightly leaning to the right side (as you can see on the picture below)

I failed using the orientation constraint tool. I’d like to know if there are videos or tutorials on how to use this tool, because I can’t manage to straight it up…
Thank you for reading

Hi Louis,

Can you please walk me through your steps so that I can see where the problem might be?
Then I’ll be able to help you and improve the behavior of the tool, if it’s not clear.

Thank you,