i have the existing contoure line of a land . and i must make a development for this land by create a new design(change the elevation of the ground) and tnis must done by creating a new contoure line as a design contoure.
Apologies, but this is not a question for the help forums. What you need is a tutorial at minimum. You should probably take a training course of some sort before you attempt something of this level. Cheers.