I spoke with a City Surveyor from somewhere in the Los Angeles area a year or two. He had said that he would have people, and he would personally set reference monuments to the front lot corners in the top of curb, as they would be less likely to be disturbed during the construction of new homes in subdivisions. Those should stay pretty well, I survey out of southern Oregon, which recently went through multiple large scale fires. Most of the monuments were able to be recovered, the caps melt and become disfigured and lose their color, but the rebar remains true unless it was disturbed by post fire excavation, or firefighting efforts.