I wanted a way to slow down bad people, other than carry chunks of rock or build defensive walls far away close to water. So, why not mud?
What exactly my mod propose:
To build mud (the same than natural), but only on four types of soil (no on marshy soil, rock or sand). Fertility is retained once removed. Not removable by the "remove flooring" tool, but you can remove it with some hay and labor (same for vanilla Mud).
Razor wire (only for Ideology DLC), almost the same as Ancient razor wire.
Take a look at my others mods, in particular Encounter Baby Animals, and the last update of Some more jobs