Heavy rains across the Iguazú river basin in October 2026 caused water flow at Iguazú Falls to reach 10 times its typical volume, leading to the temporary closure of tourist walkways. Scientists attribute the surge to the Super El Niño weather pattern, which has driven extreme precipitation in Brazil.
Iguazú Falls, a UNESCO World Heritage site, consists of a complex of cascades spanning more than a mile along the border of Argentina and Brazil. While the falls typically experience a water flow of approximately 1.5 million liters per second, recent measurements showed a significant increase. According to local government records reported by Guardian News, the flow reached 15 million liters per second.
CNN reported that flow peaked on Monday, October 12, 2026, at 11.8 million liters per second, which was the highest flow recorded this year. The rising red, muddy waters of the Iguazú river reached the metal catwalks that usually sit several feet above the water line. Consequently, park officials closed the walkways for safety as the river continued to rise. The park's director stated the closure was necessary because "it just keeps raining."
The scale of the event is measured by the 15 million liters per second flow rate, which is 10 times the standard volume. To put this in perspective, the typical 1.5 million liter per second flow is equivalent to roughly 396,000 gallons per second; the peak flow of 15 million liters per second represents nearly 4 million gallons of water passing over the cliffs every second. The surge was high enough to lap against the bottom of tourist infrastructure that normally remains dry.
The immediate impact began in mid-October when Argentina temporarily closed the falls, with the site partially reopening by Wednesday, October 14, 2026. However, ongoing rains linked to the Super El Niño mean that water levels remain volatile. These weather patterns are also cited as the cause of rare wildflower blooms in the Atacama Desert in Chile. Future access to the falls will depend on the duration of the rain and any necessary repairs to the walkways.