The Río Álamo, is a stream in the state of Tamaulipas, Mexico, and is a tributary of the Rio Grande. It is impounded by , which was completed in 2001 and diverts water to the on the Rio San Juan, another tributary of the Rio Grande. The Rio Alamo enters the Rio Grande (Rio Bravo del Norte in Mexico) at Rio Grande river kilometer 422 kilometres (262 mi), about 20 kilometres (12 mi) downriver from Falcon Dam.