Land can be transient. Beachside communities are having tough conversations right now about this topic. In California the mean high tide line is where beachfron

Land can be transient. Beachside communities are having tough conversations right now about this topic. In California the mean high tide line is where beachfront property legally ends. But the mean tide is moving inward every year. There are parts of California that will need to retreat in the next 100 years; properties have already been condemned.