These are photos of watersheds and treatment plants I visited while reporting in Tijuana. La Presa (dam) Abelardo L. Rodríguez (upper left). Treated wastewater shoots into a channel on Blvd. Olivos in Tijuana (upper right) after going through four stages of cleaning at the La Morita wastewater treatment plant (lower left). The Tijuana River watershed knows no boundary, even the U.S.-Mexico border wall (lower right).