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Brazil19 states · ONS official data

Reservoir Watch

Real-time fill levels for 102 Brazilian hydroelectric reservoirs across 19 states. Data updated 3× daily.

Average fill

43.7%

Total volume

249 km³

Reservoirs

102

Critical

2

Low level

7

By ONS subsystem

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Status:Critical (<20%)Low (20–40%)Normal / High (>40%)

Brazil at a glance

National average fill

43.7%

249,418 of 571,021 hm³ stored

Reservoirs

102

States

19

Total capacity

571 km³

Volume stored

249 km³

Critical

2

Low level

7

National fill — multi-year

ONS subsystems

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By state

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Sorted by capacity

All reservoirs

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Dataset coverage

80%of national storage capacity has public data

Tracked

102

reservoirs

With data

102

reservoirs

Tracked capacity

571,021

hm³

Source: ONS — Operador Nacional do Sistema Elétrico · ANA — Agência Nacional de Águas

Covers major reservoirs in the ONS hydrology monitoring system. Brazil has thousands more smaller reservoirs not yet tracked.

About reservoirs in Brazil

As of June 10, 2026, the reservoirs we track across Brazil that report live levels hold roughly 249,418 hm³ of water — about 43.7% of their combined capacity. Taken together, Brazil's reservoirs are within their normal operating range.

Across the region, 2 reservoirs are at critically low levels and 7 are low. PORTO PRIMAVERA is the fullest at 105.0%, while C.BRANCO-1 is the lowest at 11.2%.

Over the most recent week on record, 28 reservoirs rose and 31 reservoirs fell across Brazil.

Storage figures for Brazil come from ONS; the most recent reading is from June 10, 2026. Each reservoir below links to its own page with full history and seasonal context.

Brazil at a glance

Reservoirs tracked
102
Average fill
43.7%
Water stored
249,418 hm³
Combined capacity
571,021 hm³
At critically low levels
2
Fullest
PORTO PRIMAVERA (105.0%)
Lowest
C.BRANCO-1 (11.2%)
Last updated
June 10, 2026

Frequently asked questions

How full are reservoirs in Brazil right now?

As of June 10, 2026, the reservoirs tracked in Brazil that report live levels are 43.7% full overall, holding about 249,418 hm³ of water.

How many reservoirs are there in Brazil?

reservoirs.earth tracks 102 reservoirs in Brazil, with a combined storage capacity of 571,021 hm³.

Which reservoir in Brazil is the fullest?

PORTO PRIMAVERA is currently the fullest reservoir in Brazil, at 105.0% of capacity.

Which reservoir in Brazil is the lowest?

C.BRANCO-1 is currently the lowest in Brazil, at 11.2% of capacity.

Where does the reservoir data for Brazil come from?

All storage figures for Brazil come from ONS, an official source, last updated June 10, 2026.