SAMUEL
Rondônia · AMAZONAS
Capacity
3,493.44 hm³
Coordinates
-8.752°N, 63.454°W
Operator
ONS
35.3% full
Current fill
35.3%vs 7 days ago
-2.4%losing
vs 1 year ago
N/A7-day trend
↓falling
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 3,493.44 hm³ |
| Usable capacity | 2,550.2 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | JAMARI |
| Province | Rondônia |
| River basin | AMAZONAS |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -8.752, -63.454 · Open in Google Maps
About SAMUEL
As of September 9, 2026, SAMUEL is filled to 35.3% of its total capacity, holding roughly 900 hm³ of water out of a maximum 3,493 hm³. At this level the reservoir is low. Of that total, about 2,550 hm³ is usable (live) storage.
Over the most recent week on record the fill level has fallen by 2.4 percentage points.
Across the readings we hold for SAMUEL — 52 data points between September 26, 2025 and September 9, 2026 — the level has ranged from a low of 0.0% (November 14, 2025) to a high of 96.7% (May 1, 2026). On average the reservoir is fullest around April and at its lowest around November.
It is operated by ONS primarily for hydroelectric power. It lies within the AMAZONAS basin at 8.752°S, 63.454°W.
Key facts
- Current fill level
- 35.3%
- Water stored
- 900 hm³
- Total capacity
- 3,493 hm³
- Usable capacity
- 2,550 hm³
- 7-day change
- ▼ 2.4 pts
- Primary use
- Hydroelectric power
- River
- JAMARI
- River basin
- AMAZONAS
- Operator
- ONS
- Coordinates
- 8.752°S, 63.454°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 35.3% | 900 |
| 4 Sep 2026 | 37.6% | 960 |
| 28 Aug 2026 | 43.2% | 1,101 |
| 21 Aug 2026 | 48.9% | 1,246 |
| 14 Aug 2026 | 53.7% | 1,369 |
| 7 Aug 2026 | 58.8% | 1,499 |
| 31 Jul 2026 | 63.1% | 1,610 |
| 24 Jul 2026 | 69.9% | 1,783 |
| 17 Jul 2026 | 74.6% | 1,903 |
| 10 Jul 2026 | 77.9% | 1,988 |
| 3 Jul 2026 | 83.3% | 2,124 |
| 26 Jun 2026 | 86.3% | 2,200 |