No, I want them to be on top, as this shows the sewer map, with the houses they connect to in the background. Otherwise, the sewer detail will be lost. And there is a lot of that to come.

Also, the above ground detail will be severely cut back, anyway.

It is in the very first annual. And it is fairly easy to draw more symbols if you need. Though each symbol has 2 sheets to it.

See this video by Ralf on that annual.

(1) Live Mapping: Sarah Wroot Overland (Annual 2007) - YouTube

For example, I just created a Contour Above, and Contour Below tool, with a Contour Outline as a separate entity, in case i wanted to hide it.

I generally use lighter as higher ground, and darker as lower ground. I can also apply various effects such as lighted bevel, or edge fade, if I wanted.

Have you tried the CSUAC and Vintyri Archive collections?

Annual No 12. (134/12 = 11 with 2 left over, ie 2nd issue of Annual 12).