Arroyos and Shorelines belong to the people of Mexico. Arroyos is the name given to the dry washes that flood from time to time when there are storms and carry a volume of surface water into the sea. Under the law, the beach up to the mean high tide line is federal property, and the next 10 meters is “Zona Federal.” In that zone land can be used (the process is a federal “concession,” or annual rental, very cheap) but cannot be owned, and no permanent structures can be built on it. Use of the federal zone is available first to the adjoining land owners, and if they don’t want it or ask for the concession, then the concession can go instead to anyone else – typical uses are beachfront activites and sales.

Arroyos are not all officially designated, and there may be some question in a small one whether it has been surveyed and designated, or even meets the definition. Since the arroyo floors are natural roadbeds, of obvious use for traveling, an interesting side-effect of this law is that these routes are property of the federal government and not of the adjoining landowners, and therefore can be used by all without permission. On the other hand, especially if the arroyo in question is small and narrow and passes by an outpost of civilization, courtesy suggests contact, a polite hello, and a request to pass.