BOA ESPERANÇA
Piauí · PARNAIBA
Capacity
5,085 hm³
Coordinates
-6.751°N, 43.568°W
Operator
ONS
60.2% full
Current fill
60.2%vs 7 days ago
-2.0%losing
vs 1 year ago
N/A7-day trend
↓falling
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 5,085 hm³ |
| Usable capacity | 1,912 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | PARNAÍBA |
| Province | Piauí |
| River basin | PARNAIBA |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -6.751, -43.568 · Open in Google Maps
About BOA ESPERANÇA
As of September 9, 2026, BOA ESPERANÇA is filled to 60.2% of its total capacity, holding roughly 1,150 hm³ of water out of a maximum 5,085 hm³. At this level the reservoir is within its normal operating range. Of that total, about 1,912 hm³ is usable (live) storage.
Over the most recent week on record the fill level has fallen by 2.0 percentage points.
Across the readings we hold for BOA ESPERANÇA — 52 data points between September 26, 2025 and September 9, 2026 — the level has ranged from a low of 22.7% (December 5, 2025) to a high of 100.0% (May 1, 2026). On average the reservoir is fullest around May and at its lowest around November.
It is operated by ONS primarily for hydroelectric power. It lies within the PARNAIBA basin at 6.751°S, 43.568°W.
Key facts
- Current fill level
- 60.2%
- Water stored
- 1,150 hm³
- Total capacity
- 5,085 hm³
- Usable capacity
- 1,912 hm³
- 7-day change
- ▼ 2.0 pts
- Primary use
- Hydroelectric power
- River
- PARNAÍBA
- River basin
- PARNAIBA
- Operator
- ONS
- Coordinates
- 6.751°S, 43.568°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 60.1% | 1,150 |
| 4 Sep 2026 | 62.2% | 1,189 |
| 28 Aug 2026 | 65.8% | 1,259 |
| 21 Aug 2026 | 69.3% | 1,325 |
| 14 Aug 2026 | 73.1% | 1,398 |
| 7 Aug 2026 | 76.7% | 1,466 |
| 31 Jul 2026 | 79.1% | 1,513 |
| 24 Jul 2026 | 82.3% | 1,574 |
| 17 Jul 2026 | 85.6% | 1,636 |
| 10 Jul 2026 | 88.0% | 1,682 |
| 3 Jul 2026 | 90.0% | 1,720 |
| 26 Jun 2026 | 92.2% | 1,762 |