How to find the "best fit" line of 1m interval section lines.

[Shanny9]

I have been provided with a file that has minimal information.  It is the face of a spillway with section lines at 1m intervals. 

I have been requested to come up with a line of best fit from the section lines. The initial survey information has not been provided to me so this is all I have to work with. 

I've attached a photo showing the section lines in an isometric view.  How can i find the average line between all of these lines?

Any help is appreciated, let me know if you have any questions.

Thanks in advance.

[AlmasSuljevic]

Hi Shannon,

Can you give us more information of what you are trying to do. Seeing that image did not help me. Do you want to create some kind of "best fit" alignment or something else? Drawing would be helpful, too.