Itaipu opens gates as Paraná rises in Misiones

The operation began at 1:50 a.m. on Sunday and was scheduled to control the reservoir level. The initial discharge was about 1,700 cubic meters per second, reaching 3,800 m³/s during the day. On Monday, September 14, the spill was around 2,100 m³/s.

According to the plant, the discharge will continue while hydrological conditions keep the reservoir level high. The spillway was scheduled to operate until 4 p.m. on Monday, with a reopening planned for 10 p.m.

The water released by Itaipu joins the Paraná River downstream of the dam, adding to the flow that continues south. However, opening the spillway does not automatically mean Misiones will face an extraordinary flood. River evolution depends on multiple factors: the flow already carried by the Paraná, contributions from its tributaries, ongoing rains in the basin, and the behavior of upstream and downstream levels of Itaipu. The increased discharge does not propagate immediately and uniformly to all ports, and it can change along the course according to the hydrological conditions of each sector.

Situation at Misiones ports (Monday, September 14, at noon):

• Puerto Libertad: 18.67 m (down 0.13 m). Alert: 29 m. Evacuation: 31 m.
• Eldorado: 13.95 m (up 0.05 m). Alert: 23 m. Evacuation: 25 m.
• Puerto Maní: 5.50 m (down 0.33 m). Alert: 9.50 m. Evacuation: 10 m.
• Santa Ana: 8.20 m (up 0.02 m). Alert: 9.30 m. Evacuation: 9.80 m.
• Posadas: 10.24 m (stable). Alert: 11 m. Evacuation: 12 m.

The Itaipu level recorded by the Prefecture was 113.17 m, an increase of 10.62 m compared with the measurement taken 24 hours earlier. None of the five consulted ports reached alert level, although Eldorado and Santa Ana show a rising trend. Evolution in the coming days will depend on the duration of the spillway opening, the volume discharged, rains in the basin, and the behavior of the main tributaries.