Ninational hydroelectric dam Itaipú reopened its spillway late October 2026, releasing 3.1 million litres of water per second. The decision followed a brief closure intended to manage rising water levels along the Paraná River. The hydroelectric plant, located between Paraguay and Brazil, continues monitoring increased river inflows.
Meanwhile, nearby communities remain cautious as authorities assess the effects of recent flooding.
Changing water levels and spillway operations
The Itaipú spillway remained open for 26 consecutive days before authorities closed it on 25 October. The closure began at 17:32, allowing the reservoir to retain additional water. Engineers wanted to reduce the impact of the Iguazú River’s rising flow. However, the plant reopened its left spillway channel the following morning.
The decision followed forecasts that the Iguazú River could reach approximately 20 million litres per second. Consequently, Itaipú Binacional adjusted its operations to manage the incoming water. The Paraná River measured 115 metres above sea level at the Friendship Bridge station on 26 October. Officials also expected further changes as the rivers continued responding to rainfall.
Earlier in October, the situation had become particularly concerning around Ciudad del Este. On 14 October, the Paraná River exceeded 121 metres above sea level. Rising waters threatened riverside neighbourhoods, particularly San Rafael and San Agustín. Itaipú coordinated preventive evacuations and assistance for affected families. By 14 October, 183 families had relocated from San Rafael alone.
Communities continue monitoring the situation
Although water levels subsequently declined, flooding continued affecting residents in several riverside areas. On 20 October, Itaipú Binacional reported that the Paraná River had reached 118 metres. Two days later, the measurement fell further to 116.81 metres. Nevertheless, the organisation advised displaced families against returning home prematurely.
Furthermore, the Itaipú spillway forms part of a wider hydrological monitoring strategy. Engineers assess rainfall, tributary flows and reservoir conditions before adjusting water releases. The organisation publishes daily updates through its Hydrological Bulletin. Residents can consult these reports to follow changing river conditions and potential risks.
The latest information from Yacyretá, published on 28 October, also highlighted continued caution. Its report indicated that incoming flows remained above historical averages. Although downstream water levels showed a gradual decline, they remained above alert and flood thresholds. At Ayolas, measurements also remained above the established flood threshold.
Electricity generation continues normally
Despite the changing water conditions, Itaipú maintained normal electricity generation throughout the operation. The plant follows instructions from Paraguay’s National Electricity Administration and Brazil’s National Electric System Operator.
The Itaipú spillway therefore remains an important part of managing excess water safely. However, authorities continue monitoring conditions rather than assuming the flooding has ended. For residents along the Paraná River, following official updates remains essential. The coming days will help determine how quickly affected communities can return to normal.
Also read: Iguazu Falls Welcomes Visitors Again After Safety Shutdown Due To Record Flows.
