TRÊS MARIAS
Minas Gerais · SAO FRANCISCO
Capacity
19,528 hm³
Coordinates
-18.218°N, 45.262°W
Operator
ONS
Current fill
97.5%vs 7 days ago
-0.4%losing
vs 1 year ago
+17.4%year-over-year
7-day trend
→stable
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 19,528 hm³ |
| Usable capacity | 15,278 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | SÃO FRANCISCO |
| Province | Minas Gerais |
| River basin | SAO FRANCISCO |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -18.218, -45.262 · Open in Google Maps
About TRÊS MARIAS
As of June 10, 2026, TRÊS MARIAS is filled to 97.5% of its total capacity, holding roughly 14,892 hm³ of water out of a maximum 19,528 hm³. At this level the reservoir is high. Of that total, about 15,278 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (-0.4 pts), and it is 17.4 points above its level on the same date a year earlier.
Across the readings we hold for TRÊS MARIAS — 52 data points between June 27, 2025 and June 10, 2026 — the level has ranged from a low of 51.8% (December 12, 2025) to a high of 102.3% (April 17, 2026). On average the reservoir is fullest around April and at its lowest around December.
It is operated by ONS primarily for hydroelectric power. It lies within the SAO FRANCISCO basin at 18.218°S, 45.262°W.
Key facts
- Current fill level
- 97.5%
- Water stored
- 14,892 hm³
- Total capacity
- 19,528 hm³
- Usable capacity
- 15,278 hm³
- 7-day change
- ▼ 0.4 pts
- Year-on-year
- ▲ 17.4 pts
- Primary use
- Hydroelectric power
- River
- SÃO FRANCISCO
- River basin
- SAO FRANCISCO
- Operator
- ONS
- Coordinates
- 18.218°S, 45.262°W
- Last updated
- June 10, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 10 Jun 2026 | 97.5% | 14,892 |
| 5 Jun 2026 | 97.9% | 14,951 |
| 29 May 2026 | 98.5% | 15,046 |
| 22 May 2026 | 99.1% | 15,144 |
| 15 May 2026 | 99.7% | 15,237 |
| 8 May 2026 | 100.3% | 15,327 |
| 1 May 2026 | 101.2% | 15,464 |
| 24 Apr 2026 | 101.8% | 15,558 |
| 17 Apr 2026 | 102.3% | 15,628 |
| 10 Apr 2026 | 101.8% | 15,547 |
| 3 Apr 2026 | 101.1% | 15,452 |
| 27 Mar 2026 | 100.3% | 15,324 |
Frequently asked questions
What is the current water level of TRÊS MARIAS?
As of June 10, 2026, TRÊS MARIAS is at 97.5% of its capacity, holding approximately 14,892 hm³ of water, according to ONS – Operador Nacional do Sistema Elétrico data.
Is TRÊS MARIAS reservoir full?
TRÊS MARIAS is essentially full, sitting at 97.5% of capacity as of June 10, 2026.
Is the water level at TRÊS MARIAS rising or falling?
The level at TRÊS MARIAS has been broadly stable over the latest week on record (-0.4 points).
How much water can TRÊS MARIAS hold?
TRÊS MARIAS has a total capacity of 19,528 hm³, of which about 15,278 hm³ is usable storage.
Where is TRÊS MARIAS reservoir located?
TRÊS MARIAS is located in Minas Gerais, Brazil, within the SAO FRANCISCO basin (coordinates 18.218°S, 45.262°W).
What is TRÊS MARIAS used for?
TRÊS MARIAS is used primarily for hydroelectric power, and is managed by ONS.