SERRA DA MESA
Goiás · TOCANTINS
Capacity
54,400 hm³
Coordinates
-13.834°N, 48.306°W
Operator
ONS
45.1% full
Current fill
45.1%vs 7 days ago
-0.8%losing
vs 1 year ago
N/A7-day trend
→stable
Drought context
Storage vs October average
81%of normal
45.1% full on 2026-10-14, against an average of 55.5% for October across 2 years of readings (-10.4 points).
Rain over the last three months · 21 September 2026
Near normal
In the three months to 21 September 2026 the area around SERRA DA MESA 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 −0.70). Rain, not storage. Brazil drought figures →
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 54,400 hm³ |
| Usable capacity | 43,250 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | TOCANTINS |
| Province | Goiás |
| River basin | TOCANTINS |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -13.834, -48.306 · Open in Google Maps
About SERRA DA MESA
As of October 14, 2026, SERRA DA MESA is filled to 45.1% of its total capacity, holding roughly 19,493 hm³ of water out of a maximum 54,400 hm³. At this level the reservoir is within its normal operating range. Of that total, about 43,250 hm³ is usable (live) storage.
Over the most recent week on record the fill level has held broadly steady (-0.8 pts).
Across the readings we hold for SERRA DA MESA — 52 data points between October 31, 2025 and October 14, 2026 — the level has ranged from a low of 45.1% (October 14, 2026) to a high of 63.2% (April 24, 2026). On average the reservoir is fullest around April and at its lowest around October.
It is operated by ONS primarily for hydroelectric power. It lies within the TOCANTINS basin at 13.834°S, 48.306°W.
Key facts
- Current fill level
- 45.1%
- Water stored
- 19,493 hm³
- Total capacity
- 54,400 hm³
- Usable capacity
- 43,250 hm³
- 7-day change
- ▼ 0.8 pts
- Primary use
- Hydroelectric power
- River
- TOCANTINS
- River basin
- TOCANTINS
- Operator
- ONS
- Coordinates
- 13.834°S, 48.306°W
- Last updated
- October 14, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 14 Oct 2026 | 45.1% | 19,493 |
| 9 Oct 2026 | 45.8% | 19,826 |
| 2 Oct 2026 | 47.1% | 20,366 |
| 25 Sep 2026 | 48.4% | 20,942 |
| 18 Sep 2026 | 49.7% | 21,508 |
| 11 Sep 2026 | 51.0% | 22,049 |
| 4 Sep 2026 | 52.1% | 22,551 |
| 28 Aug 2026 | 53.3% | 23,070 |
| 21 Aug 2026 | 54.5% | 23,554 |
| 14 Aug 2026 | 55.3% | 23,913 |
| 7 Aug 2026 | 56.0% | 24,237 |
| 31 Jul 2026 | 56.8% | 24,553 |