SANTO ANTONIO
Rondônia · AMAZONAS
Useful capacity
489.87 hm³
Coordinates
8.801°S, 63.950°W
Operator
ONS
35.9% of useful capacity
Current fill
35.9%of useful capacity
vs 7 days ago
-16.0 pplosing
vs 1 year ago
0.0 ppyear-over-year
7-day trend
↓falling
Drought context
Storage vs October average
84%of normal
35.9% full on 2026-10-26, against an average of 42.7% for October across 2 years of readings (-6.8 points).
Rain over the last three months · 11 October 2026
Extremely dry
In the three months to 11 October 2026 the area around SANTO ANTONIO had extremely little rain for the season, a shortfall seen about one year in forty. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index −2.64). Rain, not storage. Brazil drought figures →
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 2,283 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°S, 63.950°W · Open in Google Maps
About SANTO ANTONIO
As of October 26, 2026, SANTO ANTONIO is at 35.9% of useful capacity, holding 175.8 hm³ of 489.87 hm³. Of the 2,283 hm³ total capacity, that is 7.7%. At this level the reservoir is low.
Over the most recent week on record the fill level has fallen by 16.0 percentage points, and it sits close to where it was a year earlier.
Across the readings we hold for SANTO ANTONIO — 65 data points between October 26, 2025 and October 26, 2026 — the level has ranged from a low of 35.9% (October 26, 2025) to a high of 100.0% (November 28, 2025). On average the reservoir is fullest around April and at its lowest around August.
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
- 35.9% of useful capacity
- Water stored
- 175.8 hm³
- Total capacity
- 2,283 hm³
- Usable capacity
- 489.87 hm³
- 7-day change
- ▼ 16.0 pp
- Year-on-year
- No change
- Primary use
- Hydroelectric power
- River
- MADEIRA
- River basin
- AMAZONAS
- Operator
- ONS
- Coordinates
- 8.801°S, 63.950°W
- Last updated
- October 26, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 26 Oct 2026 | 35.9% | 175.8 |
| 25 Oct 2026 | 36.7% | 179.7 |
| 24 Oct 2026 | 35.9% | 175.8 |
| 23 Oct 2026 | 35.9% | 175.8 |
| 22 Oct 2026 | 35.9% | 175.8 |
| 21 Oct 2026 | 35.9% | 175.8 |
| 20 Oct 2026 | 42.3% | 207.2 |
| 19 Oct 2026 | 51.9% | 254.3 |
| 18 Oct 2026 | 51.9% | 254.3 |
| 17 Oct 2026 | 52.7% | 258.3 |
| 16 Oct 2026 | 53.5% | 262.2 |
| 15 Oct 2026 | 51.1% | 250.4 |