The Itaipu spillway was opened on schedule in the early hours of September 13 to control the reservoir after rains in the basin, starting with a flow of 1,700 cubic meters per second, which was confirmed to increase to 3,100 cubic meters per second at 2:43 AM.
The opening began at 1:50 AM on Sunday from the left side of the spillway. This information was released by the power plant’s communication office and was also covered in news reports regarding the operation.
According to the announcement, Itaipu continued to meet the energy needs of Brazil and Paraguay. The water release was presented as a measure to control the reservoir level.
Rainfall in Rivers Feeding the Reservoir Prompted the Opening
OBemdito’s report links the operation to the rains in the incremental basin of Itaipu, formed by the rivers that directly contribute to the reservoir in this section of the basin.
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When the received volume increases, the operation must monitor the level changes. The release is one of the methods to manage water beyond the dam.
The justification provided was for this hydrological control. The information released by the communication office did not announce any halt in electricity generation or interruptions in service to the two countries.
The Left Channel Started Releasing 1,700 Cubic Meters Per Second
The initial reported flow was 1,700 m³/s. This unit indicates the volume of water passing through a specific point every second of the spillway’s operation.
Since one cubic meter equals one thousand liters, this flow rate corresponds to 1.7 million liters per second. This conversion helps visualize the magnitude of the flow.
The figure refers to the initial moment reported. Therefore, it should not be presented as a fixed flow rate for the entire Sunday or for subsequent days.
The Second Level Was Reached 53 Minutes After the Start
At 2:43 AM, the flow increased to 3,100 m³/s, according to the update reported. The interval since the initial opening was 53 minutes.
In volume, the new level corresponds to 3.1 million liters every second. This water is released from the spillway, as described by the power plant operation.
This sequence reflects a scheduled adjustment in the opening during the early morning. It does not authorize assuming the same flow rate for all subsequent hours without new measurements.
The Prediction of 3,800 Cubic Meters Was Not a Confirmed Measurement
The communication office stated that the flow could reach 3,800 m³/s by the afternoon, with a reduction expected by the end of the day. This statement described an operational possibility at that time.
Therefore, the flow confirmed in this update is 3,100 m³/s at 2:43 AM. The prediction for the afternoon was not established as a confirmed fact by the report.
This difference is significant when numbers circulate outside their original context. An operational plan may change based on incoming data, while a measurement records an observed condition.
The Water from the Spillway Follows a Different Path Than Turbined Water
The spillway allows for the discharge of water without that volume passing through the generation turbines. The turbined water, on the other hand, is part of the process used to produce energy at the hydropower plant.
Thus, discharged flow and electrical power are not equivalent measurements. A flow rate of 3,100 cubic meters per second does not indicate how many megawatts the power plant was generating at that moment.
To calculate generation, other operational information would be necessary. The released statement addresses reservoir control and does not provide a conversion of this volume into electricity production.
The function of the turbines also appears in research to generate electricity at existing dams, another situation that helps distinguish hydraulic infrastructure from effective energy production.
Generation for Brazil and Paraguay continued, according to the advisory
Itaipu’s communication affirms the continuity of meeting the energy needs of both countries. This is the information released regarding supply during the spillway opening.
The presence of discharged water does not mean all generating units were shut down. The operation of the spillway and power generation serve different functions at the plant.
There is also no basis in this update to announce a blackout. The information available indicates the maintenance of service while the team monitors the hydrological condition of the reservoir.
The closure will depend on the evolution of the hydrological conditions
According to the advisory, the spill should remain open until conditions allow for the closure of the spillway. A definitive time to end the operation was not provided in the reproduced communication.
This decision is linked to the evolution of the conditions of water received and stored. Thus, an estimate made during the night does not replace monitoring throughout the day.
To understand the operation after the described period, it is necessary to consult hydrological updates. The opening on Sunday is a documented event, without assuming it will remain the same indefinitely.
The hydrological bulletin also monitors the river below the plant
The report advises consulting the Itaipu Hydrological Bulletin, updated daily on the official website. It allows tracking information about water levels in the Paraná River downstream from the dam.
Downstream refers to the section where the water flows after passing through the structure. The term helps differentiate the reservoir from the conditions observed below the plant.
This separation prevents treating all river data in the region as if it were a single measurement. Each bulletin needs to be read with the corresponding location, unit, and time.
Flooding at the Falls pertains to another observation point in the region
Reports also mentioned restrictions at the Iguaçu Falls following an increase in flow. However, that data refers to the Iguaçu River, not to the channel of the Itaipu spillway.
The Paraná and the Iguaçu appear in the same regional news, but they are distinct hydrological references. Therefore, values from one cannot substitute the figures from the operation of the other.
In this update, the focus is on the scheduled opening at Itaipu. Information regarding visitation and reopening of walkways depends on separate announcements from those responsible for these tourist spaces.
The record from the night shows how the operation responded to the increase in water
The confirmed timeline includes an opening at 1:50 AM, an initial flow of 1,700 cubic meters per second, and a rise to 3,100 cubic meters per second at 2:43 AM. These are the reported milestones for the event.
The justification was to manage the reservoir after rainfall in the contributing rivers. Continuous energy and hydrological monitoring complete the picture presented by the advisory of the binational power plant.
For those tracking Itaipu, the next relevant data point is the subsequent evolution of flow and level. The update should come from measurements, not from repeating previous forecasts.
When you see an open spillway, do you usually follow the flow data or just the images of water passing through the dam?
