Travesía de Ibicuy

In the lower reaches of the Paraná Delta, where endless willow groves give way to broad brown water, the Paraná Ibicuy river carves a peaceful waterway far from the urban bustle. Here in Ibicuy, in the province of Entre Ríos, the Travesía de Ibicuy brings open water swimmers together in late January. Organized by Master Natación Buenos Aires, the race sets its base right along the riverbank at the S.O.E.C.R.A camping facilities. Swimmers choose between distances of 400, 3,000, and 7,000 meters along the quiet currents of the Paraná Ibicuy branch. Out on the water, participants experience an intimate connection with the river and a warm camaraderie that defines the day. After reaching the finish line, the gathering turns into an open celebration directly on the riverfront. In past editions, the venue came alive with live music, a DJ, and a festive batucada show with dancers performing for the athletes on the shore.

The Paraná Ibicuy: water and sediment of the lower delta

The landscape surrounding Ibicuy sits entirely below six meters in elevation, forming a low-lying terrain vulnerable to flooding when the river rises. The Paraná Ibicuy itself flows as one of the primary branches of the Lower Delta, which represents the final geographic division of the Paraná river system alongside the Upper and Middle sections. Heavily laden with silt, the active delta relentlessly deposits sediment into the Río de la Plata, advancing into the open estuary at a steady pace of 50 to 90 meters each year.

Where the Paraná Ibicuy runs: from the Pavón to the Guazú

The Paraná Ibicuy, one of the most important branches of the Paraná Delta, is the continuation of the Paraná Pavón. It runs through the south of Entre Ríos and marks the boundary between the Gualeguay department and the Islas del Ibicuy department. Downstream a minor branch, the Río Paranacito, splits off, and the Paraná Ibicuy finally joins the Paraná Guazú near Puerto Ibicuy. Ibicuy lies 182 km from Buenos Aires, reached through the Zárate–Brazo Largo road-and-rail complex and Ruta Nacional 12. The climate is temperate, with moderate temperatures and sufficient rainfall, and winds from the south-southeast prevail.

Sixteenth-century voyages: Solís on the freshwater sea

Centuries before swimmers began racing through these channels, early explorers navigated this vast alluvial system. Explorer Juan Díaz de Solís encountered these expansive waters and named the great Río de la Plata estuary the Mar Dulce, or Sweet Sea. Venturing further into the labyrinth of delta waterways, Solís discovered the Paraná River itself, originally christening it the Santa María River.

Willow forests and island fauna: the delta wilderness

Along the riverbanks of Ibicuy, the shores are dominated by dense stands of trees, forming part of the world's largest expanse of poplars and willows. Downstream along the delta network, several protected areas preserve this delicate island environment. The Isla Botija Nature Reserve, created in 1958, was one of the earliest reserves established in the lower delta, while the expansive UNESCO Paraná Delta Biosphere Reserve encompasses 886 square kilometers of river wetlands. These secluded wetlands shelter diverse wildlife, providing habitat for marsh deer, capybaras, coypus, neotropical river otters, Pampas cats, jaguars, and the red-faced guan. Under the surface, the Paraná Ibicuy supports a rich variety of permanent fish species. The river is home to yellow catfish, white catfish, patí, carp, boga, tarucha, and schools of sábalo.