Arroyo Cildáñez

From the murky depths of La Matanza, the Arroyo Cildáñez begins its journey. It flows northeast, then carves a southeastern path through Buenos Aires, shaping the landscape of Comunas 8 and 9. Stand here, at the edge of this waterway, and imagine the vast “Bañado de Flores,” a marshy, flood-prone area that once dominated this region. Arroyo Cildáñez snaked through this swamp, its waters intertwining with the neighborhoods of Nueva Pompeya, Villa Soldati, Flores, Parque Avellaneda, Villa Lugano, and Villa Riachuelo. The name Cildáñez echoes the legacy of Ramón Fortunato Cidañez (or perhaps Sidáñez), who acquired a farm crossed by this very arroyo in 1849. This land had once been part of the Rivadavia family’s holdings and, before them, belonged to Miguel Flores, the man whose name graces the entire “Bañado.” But Arroyo Cildáñez carries a darker moniker: the “Zanjón o arroyo de la Sangre,” or “Ditch of Blood.” This chilling nickname arose in the first half of the 20th century. Imagine the massive amounts of blood discharged into the arroyo from the slaughterhouses in Mataderos and Liniers. The water, stained crimson, flowed through the city, a grim testament to the city’s meat industry. In 1940, the first section of the Arroyo Cildáñez was encased in concrete, a process completed by 1965. Today, the waterway largely flows beneath the city streets: Justo Antonio Suárez, Coronel Cárdenas, Avenida Remedios, Avenida San Juan Bautista Lasalle, and Avenida Asturias. Its subterranean path continues under Parque Indoamericano and Parque de la Ciudad. Emerging from its concrete confines at Avenida Coronel Roca, it enters Parque Julio A. Roca. Here, something remarkable happens. Unlike other city waterways, Arroyo Cildáñez sees daylight again, flowing openly for 850 meters before joining the Riachuelo. The southern bank forms part of the Reserva Lago Lugano. And deep below, a hidden connection exists. An underground channel, built mid-20th century, links Arroyo Cildáñez to the Arroyo Maldonado, channeling excess water from the latter under Ruiz de los Llanos and Basualdo streets. The waters of Arroyo Cildáñez once even filled Lago Lugano and Lago Regatas. So, as you stand here, beside this once blood-red stream, consider its journey, from the outskirts of the city, through darkness and into the light, a vital part of Buenos Aires’ hidden history.