The Idea for submerging Pipes (and Belts soon?) is not new and possible, or do Road channels, trenches, water channels.. what ever. But to make all of that you currently need to build a Mining Tower.
Rather then that, I propose to be able to built a much smaller and CHEAPER temporary "Construction Site" thing. Maybe with a container (Workers/Foreman's Lodge / Office) and a few decals to make it looks like a construction site. There you can assign excavators and trucks, just like with the Mining tower, but the area is much smaller.
Additionally a Dirt/Gravel/Rock temporary dump (like those Concrete Lego Block dumps) to store the dug up earthwork and later dump it back, if you want to burry pipes, e.g. as it's own storage building with no Belt access, or part of the construction site building (set).
All in all, a quick, cheap thing to set up to rework certain areas.
