PROMISSÃO
São Paulo · TIETE
Useful capacity
2,127.3 hm³
Coordinates
21.297°S, 49.783°W
Operator
ONS
96.0% of useful capacity
Current fill
96.0%of useful capacity
vs 7 days ago
+4.9 ppgaining
vs 1 year ago
+54.3 ppyear-over-year
7-day trend
↑rising
Drought context
Storage vs October average
145%of normal
96.0% full on 2026-10-26, against an average of 66.4% for October across 2 years of readings (+29.6 points).
Rain over the last three months · 11 October 2026
Near normal
In the three months to 11 October 2026 the area around PROMISSÃO had rain close to normal for the season. Rainfall compared with the long-run record for the same season at this point (Copernicus Global Drought Observatory, SPI-3 index +0.72). Rain, not storage. Brazil drought figures →
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 7,408 hm³ |
| Usable capacity | 2,127 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | TIETÊ |
| Province | São Paulo |
| River basin | TIETE |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 21.297°S, 49.783°W · Open in Google Maps
About PROMISSÃO
As of October 26, 2026, PROMISSÃO is at 96.0% of useful capacity, holding 2,043 hm³ of 2,127 hm³. Of the 7,408 hm³ total capacity, that is 27.6%. At this level the reservoir is high.
Over the most recent week on record the fill level has risen by 4.9 percentage points, and it is 54.3 points above its level on the same date a year earlier.
Across the readings we hold for PROMISSÃO — 65 data points between October 26, 2025 and October 26, 2026 — the level has ranged from a low of 41.7% (October 26, 2025) to a high of 99.5% (August 14, 2026). On average the reservoir is fullest around August and at its lowest around November.
It is operated by ONS primarily for hydroelectric power. It lies within the TIETE basin at 21.297°S, 49.783°W.
Key facts
- Current fill level
- 96.0% of useful capacity
- Water stored
- 2,043 hm³
- Total capacity
- 7,408 hm³
- Usable capacity
- 2,127 hm³
- 7-day change
- ▲ 4.9 pp
- Year-on-year
- ▲ 54.3 pp
- Primary use
- Hydroelectric power
- River
- TIETÊ
- River basin
- TIETE
- Operator
- ONS
- Coordinates
- 21.297°S, 49.783°W
- Last updated
- October 26, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 26 Oct 2026 | 96.0% | 2,043 |
| 25 Oct 2026 | 94.3% | 2,006 |
| 24 Oct 2026 | 91.3% | 1,943 |
| 23 Oct 2026 | 90.8% | 1,932 |
| 22 Oct 2026 | 90.8% | 1,932 |
| 21 Oct 2026 | 91.1% | 1,938 |
| 20 Oct 2026 | 91.3% | 1,943 |
| 19 Oct 2026 | 91.1% | 1,938 |
| 18 Oct 2026 | 90.8% | 1,932 |
| 17 Oct 2026 | 90.3% | 1,922 |
| 16 Oct 2026 | 89.6% | 1,906 |
| 15 Oct 2026 | 89.6% | 1,906 |