Pipes

It would be awesome to be able to dig a trench and put the pipes under ground. That way it could save room. So like the panel you see all the resources you add a panel to see all the pipes.

You can already do that, just dig a trench, put the pipe in, and refill the trench. The only thing that's missing is some way of viewing/accessing underground pipes, you pretty much have to remember where you put them.