Also where I live (a karst region) other expensive things we deal with are frost lines (frost heave is a real issue; water expands as it freezes, things in the ground don't stay in the ground if ice is expanding into their space) and limestone rock underfoot (sinkholes are a real issue; dig wrong or too deep or not carefully enough and cave in the ground right under you, or worse, someone's house right next to you).

Google Fiber wrecked entire city streets relearning these things the dumbest way possible (then left the street repair bills to the us the taxpayers, because of course they did).