Shading contours?

Hi all:

Just wondering if in Civil 3d how to shade your contours in? Like, once you build your surface and you specify your contour intervals and assign colors to your major and minor contours, Civil 3d creates your surface with contours from your survey, but is there a way to shade them all in so your entire drawing will be all hatched in shading, with the deeper spots being darker and the higher points being lighter. To show varation within a channel bed?

I have never done it before and its not normally a standard thing we do, but if anyone knows can they share some guidence? Aside from hatching in each individual poly line, which would take a collossal waste of time!

thanks again!