Legal Question in Real Estate Law in California

The problem you have is that land title records, which are the only basis on which property under California law can be bought and sold, are based on the original subdivision maps, which are laid out in metes and bounds. In slide areas the physical objects, such as roads, surveyor's monuments, and anything else on which metes and bounds are based, keep moving. Therefore GIS, which maps the actual locations of the parcels relative to all the other parcels in the city that do NOT have moving surfaces, shows the genuine original locations of each parcel. So once you get meaningful land movement, you have an irreconcilable conflict between the legal description in the land title records, and the actual correct location of the parcels. The realtors must by state law sell based on the land title records. The city is under no such obligation and is in many ways more correct in using the GIS maps to show where the parcel lines are. A solution to that conflict will have to come at the county level at least, given that the county maintains land records, or perhaps the state level with some kind of legislation. As long as the land keeps moving, however, there isn't going to be any permanent solution to the conflict. It's not something the realtors are doing wrong.