Resacas: The Old River Beds of Brownsville
Near Brownsville, Texas
The waterways that wind through Brownsville are not rivers, not canals, and not quite lakes. They are resacas, which is the Spanish word for an old riverbed. The Rio Grande has been moving for tens of thousands of years, carving new channels across the coastal plain, abandoning old ones, and leaving behind crescent-shaped bodies of water that slowly became isolated from the main flow.
What you see today in and around Brownsville is a network of resaca systems, ranging from narrow sloughs to open water wide enough to kayak. The oldest resacas are almost undetectable now, their oxbow shapes filled in by centuries of silt and plant material. The newest are the ones closest to the present river, still recognizable as old meanders cut off when the Rio Grande shifted course.
Town Resaca winds through the heart of Brownsville, threading between neighborhoods and parks. Resaca de la Palma, a few miles north, gives its name to both a state park and to the battlefield where the second engagement of the Mexican-American War was fought in eighteen forty-six, along a resaca that served as a natural defensive trench. More than three hundred bird species have been documented in and around Resaca de la Palma State Park, part of the World Birding Center network in the Rio Grande valley.
The subtropical climate and the water draw migrants and residents that cannot be found anywhere else in the United States. Altamira orioles, green jays, plain chachalacas, and ringed kingfishers live here in numbers tourists travel thousands of miles to see. The resacas are slow, still, and older than any building in the valley.
