The Southeast and Midwest submarket saw a slight improvement in its storage levels, reaching 57.4% of total capacity following a 0.1 percentage point increase.
The latest monitoring conducted by the National Electric System Operator (ONS) shows a scenario of stability and slight recovery for water levels in Brazil’s reservoirs. With a gain of 0.1 percentage points, the group covering the Southeast and Midwest is now operating at 57.4% of its storage capacity, reflecting the current dynamics of water management in the country’s primary generation basins.
While the Southeast and Midwest maintain these levels, other regions in Brazil show different indicators across their generation facilities. The South submarket currently stands out with the highest volume availability, reaching 82.5% of its capacity. Meanwhile, the North and Northeast regions report 74.2% and 69.9% of their useful volumes, respectively.
Generation Context and Energy Security
Fluctuations in reservoir levels serve as a key barometer for Brazil’s energy security, especially given a grid predominantly based on hydropower. Technical analysis from the ONS assists in planning thermoelectric dispatch and optimizing the marginal cost of operation (CMO) for the national interconnected system.
As reported by journalist Michele Rios, with data released on the afternoon of September 25, 2026, the efficient management of generation assets—such as the Belo Monte Hydroelectric Plant, where the powerhouse and tailrace structures continue to operate according to the system’s schedule—is essential for maintaining balance amid seasonal rainfall variations and constant growth in electricity load.
Expectations are that the electric sector will continue to closely monitor daily indices to ensure power supply resilience over the coming months, particularly in light of projected demand growth for the National Interconnected System (SIN).
