SAMUEL
Rondônia · JAMARI
Useful capacity
2,336.57 hm³
Coordinates
8.752°S, 63.454°W
Operator
ONS
10.7% of useful capacity
Current fill
10.7%of useful capacity
vs 7 days ago
-3.1 pplosing
vs 1 year ago
+6.4 ppyear-over-year
7-day trend
↓falling
Drought context
Storage vs October average
118%of normal
10.7% full on 2026-10-27, against an average of 9.1% for October across 2 years of readings (+1.6 points).
Rain over the last three months · 11 October 2026
Extremely dry
In the three months to 11 October 2026 the area around SAMUEL 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 −3.08). Rain, not storage. Brazil drought figures →
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 3,448 hm³ |
| Usable capacity | 2,337 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| Province | Rondônia |
| River basin | JAMARI |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 8.752°S, 63.454°W · Open in Google Maps
About SAMUEL
As of October 27, 2026, SAMUEL is at 10.7% of useful capacity, holding 249.1 hm³ of 2,337 hm³. Of the 3,448 hm³ total capacity, that is 7.2%. At this level the reservoir is critically low.
Over the most recent week on record the fill level has fallen by 3.1 percentage points, and it is 6.4 points above its level on the same date a year earlier.
Across the readings we hold for SAMUEL — 65 data points between October 27, 2025 and October 27, 2026 — the level has ranged from a low of 0.0% (November 9, 2025) to a high of 96.5% (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 JAMARI basin at 8.752°S, 63.454°W.
Key facts
- Current fill level
- 10.7% of useful capacity
- Water stored
- 249.1 hm³
- Total capacity
- 3,448 hm³
- Usable capacity
- 2,337 hm³
- 7-day change
- ▼ 3.1 pp
- Year-on-year
- ▲ 6.4 pp
- Primary use
- Hydroelectric power
- River basin
- JAMARI
- Operator
- ONS
- Coordinates
- 8.752°S, 63.454°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 10.7% | 249.1 |
| 26 Oct 2026 | 10.8% | 252.6 |
| 25 Oct 2026 | 11.2% | 261.5 |
| 24 Oct 2026 | 11.6% | 270.3 |
| 23 Oct 2026 | 12.1% | 283 |
| 22 Oct 2026 | 12.6% | 294.9 |
| 21 Oct 2026 | 13.3% | 310.1 |
| 20 Oct 2026 | 13.7% | 321 |
| 19 Oct 2026 | 14.1% | 330.4 |
| 18 Oct 2026 | 14.6% | 341.6 |
| 17 Oct 2026 | 15.1% | 352.8 |
| 16 Oct 2026 | 15.6% | 364.3 |