I wasn’t criticizing…just being flippant.Regarding criticism of authorities using large printed maps. Think in terms of having an engineer on a job site with blueprints to the house or building, not just a digital house plan you downloaded from eplans.com. Engineers, contractors, city planners still use printed blueprints, maps in addition to digital tools. Everything in the world is not on Google maps. We have giant cad printers to print digital copies of things. Sometimes, bigger is actually better.
It seems like it may be some kind of map of septic systems or sewers in the area based on what is being seen now.