You know, when drawing coordinates, you must first enter the Y axis coordinates, and then enter the X axis coordinates. And you can't bring a decimal point.
For example, the coordinate values are x:2000.000, y: 1000.000. You can just type in 1000000, or 2000000!
I'll tell you two ways. First, you can draw directly with cad, provided that you can read the drawings and imagine the actual appearance. Second, you can draw the culvert with sketch, which is more vivid, and you can save it in cad format if you want.