Heavy rains have triggered flooding, evacuations and water releases at the Itaipu hydroelectric dam -- where Paraguay, Brazil and Argentina meet.

Oct. 13 (UPI) -- Heavy rains have triggered flooding, evacuations and water releases at the Itaipu hydroelectric dam in the region where Paraguay, Brazil and Argentina meet, under conditions influenced by El Niño, according to specialists at the jointly operated facility.

The tri-border region encompasses Ciudad del Este in Paraguay, Foz do Iguaçu in Brazil and Puerto Iguazú in Argentina, near the confluence of the Paraná and Iguazú rivers. Rising waters also disrupted visits to Iguazú Falls, where authorities announced that the Argentine national park would reopen Tuesday after river flows began to decline.

Paulo Zanelli Jr., coordinator of Itaipu's flood monitoring commission, said the river basins affecting the plant have experienced significant rainfall since the second half of September under conditions influenced by El Niño, according to Brazilian outlet Paraná POP.

Some monitoring stations in the Iguazú basin recorded nearly eight inches of rain in the 72 hours preceding Monday's report, while stations in the area feeding Itaipu's reservoir recorded more than four inches.

El Niño is the warm phase of a climate pattern associated with warming waters in the equatorial Pacific and changes in atmospheric circulation. Argentina's National Meteorological Service confirmed El Niño conditions in its September report and forecast that they would persist through the September-November period.

Itaipu's Paraguayan director, Justo Zacarías, also linked current conditions to the phenomenon.

"We are experiencing an El Niño event," he said, according to ABC Color, explaining why spillway releases have become frequent.

Itaipu, jointly operated by Paraguay and Brazil on the Paraná River, is the world's third-largest hydroelectric plant by installed capacity, at 14,000 megawatts, according to the operator. All six spillway gates remain open to release water exceeding the plant's normal generating and storage capacity, ABC Color reported Monday.

In Ciudad del Este, about 60 families were evacuated from flooded areas, according to an update published Tuesday by La Nación. Teams are moving residents and their belongings to safety with support from municipal authorities, firefighters and military personnel.

In Foz do Iguaçu, a Brazilian Civil Defense assessment from Monday, cited by local media, reported that nine people needed shelter and another 16 had left their homes.

On the Argentine side, Iguazú National Park announced its reopening Tuesday after a precautionary closure as river flows reached roughly 12,000 cubic meters per second, compared with a typical flow of about 1,500, park superintendent José María Hervás told Cadena 3. Travel influencer Modojuanchi posted a video on Instagram Tuesday morning showing workers removing metal railings from the walkway leading to Devil's Throat at Iguazú Falls. The structures were to be stored away from the river to protect them from damage.

Authorities advised visitors to check which trails and walkways were open before arriving.

The Iguazú River joins the Paraná downstream from Itaipu. The plant controls releases from its reservoir but does not control the water flowing over the falls, the operator said.