 the tijuana river () is an intermittent river, 120&nbsp;mi (195&nbsp;km) long, near the pacific coast of northern baja california state in northwestern mexico and southern california in the western united states. ==location== the tijuana river drains an arid area along the u.s.âmexico border, flowing through mexico for most its course then crossing the border into southern california for its lower 5&nbsp;mi (8&nbsp;km) to empty into the ocean in an estuary on the southern edge of san diego. the tijuana river has two main tributaries. one the arroyo de alamar or rio alamar, runs in its upper reaches in the united states as cottonwood creek. it runs from its source in the laguna mountains southwestward where it is impounded in by two dams, barrett and morena, to supply water to the city of san diego. cottonwood creek is joined by the tecate creek before it enters mexico where it is known as the arroyo de alamar from the point where it enters mexico to its confluence with the larger tributary, the arroyo de las palmas, that forms the headwaters of the tijuana river within the city. the arroyo de las palmas, main tributary of the tijuana river, flows out of the mountains to the east into the reservoir behind the abelardo l. rodrÃ­guez dam. downstream from the rodrÃ­guez dam water flows through tijuana in a concrete channel to the inte
Border_rivers Borders_of_California Geography_of_San_Diego,_California International_rivers_of_North_America Landforms_of_Baja_California Ocean_pollution Rivers_of_California Rivers_of_Mexico Rivers_of_San_Diego_County,_California Rivers_of_Southern_California Water_pollution_in_the_United_States