SANTO ANTONIO
Rondônia · AMAZONAS
Capacity
2,282.8 hm³
Coordinates
-8.801°N, 63.950°W
Operator
ONS
96.8% full
Current fill
96.8%vs 7 days ago
+22.4%gaining
vs 1 year ago
N/A7-day trend
↑rising
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 2,282.8 hm³ |
| Usable capacity | 489.87 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | MADEIRA |
| Province | Rondônia |
| River basin | AMAZONAS |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -8.801, -63.950 · Open in Google Maps
About SANTO ANTONIO
As of September 9, 2026, SANTO ANTONIO is filled to 96.8% of its total capacity, holding roughly 474 hm³ of water out of a maximum 2,283 hm³. At this level the reservoir is high. Of that total, about 490 hm³ is usable (live) storage.
Over the most recent week on record the fill level has risen by 22.4 percentage points.
Across the readings we hold for SANTO ANTONIO — 52 data points between September 26, 2025 and September 9, 2026 — the level has ranged from a low of 35.9% (October 10, 2025) to a high of 100.0% (November 28, 2025). On average the reservoir is fullest around April and at its lowest around October.
It is operated by ONS primarily for hydroelectric power. It lies within the AMAZONAS basin at 8.801°S, 63.950°W.
Key facts
- Current fill level
- 96.8%
- Water stored
- 474 hm³
- Total capacity
- 2,283 hm³
- Usable capacity
- 490 hm³
- 7-day change
- ▲ 22.4 pts
- Primary use
- Hydroelectric power
- River
- MADEIRA
- River basin
- AMAZONAS
- Operator
- ONS
- Coordinates
- 8.801°S, 63.950°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 96.8% | 474 |
| 4 Sep 2026 | 74.4% | 364 |
| 28 Aug 2026 | 35.9% | 176 |
| 21 Aug 2026 | 45.5% | 223 |
| 14 Aug 2026 | 35.9% | 176 |
| 7 Aug 2026 | 37.5% | 184 |
| 31 Jul 2026 | 51.9% | 254 |
| 24 Jul 2026 | 51.9% | 254 |
| 17 Jul 2026 | 80.8% | 396 |
| 10 Jul 2026 | 99.2% | 486 |
| 3 Jul 2026 | 98.4% | 482 |
| 26 Jun 2026 | 98.4% | 482 |