SERRA DA MESA
Goiás · TOCANTINS
Useful capacity
43,250 hm³
Coordinates
13.834°S, 48.306°W
Operator
ONS
42.8% of useful capacity
Current fill
42.8%of useful capacity
vs 7 days ago
-1.3 pplosing
vs 1 year ago
-14.3 ppyear-over-year
7-day trend
↓falling
Drought context
Storage vs October average
84%of normal
42.8% full on 2026-10-26, against an average of 50.8% for October across 2 years of readings (-8.0 points).
Rain over the last three months · 11 October 2026
Near normal
In the three months to 11 October 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 −0.38). 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 |
| Province | Goiás |
| River basin | TOCANTINS |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 13.834°S, 48.306°W · Open in Google Maps
About SERRA DA MESA
As of October 26, 2026, SERRA DA MESA is at 42.8% of useful capacity, holding 18,520 hm³ of 43,250 hm³. Of the 54,400 hm³ total capacity, that is 34.0%. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has fallen by 1.3 percentage points, and it is 14.3 points below its level on the same date a year earlier.
Across the readings we hold for SERRA DA MESA — 65 data points between October 26, 2025 and October 26, 2026 — the level has ranged from a low of 42.8% (October 26, 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
- 42.8% of useful capacity
- Water stored
- 18,520 hm³
- Total capacity
- 54,400 hm³
- Usable capacity
- 43,250 hm³
- 7-day change
- ▼ 1.3 pp
- Year-on-year
- ▼ 14.3 pp
- Primary use
- Hydroelectric power
- River basin
- TOCANTINS
- Operator
- ONS
- Coordinates
- 13.834°S, 48.306°W
- Last updated
- October 26, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 26 Oct 2026 | 42.8% | 18,520 |
| 25 Oct 2026 | 43.0% | 18,606 |
| 24 Oct 2026 | 43.2% | 18,671 |
| 23 Oct 2026 | 43.4% | 18,758 |
| 22 Oct 2026 | 43.6% | 18,844 |
| 21 Oct 2026 | 43.8% | 18,931 |
| 20 Oct 2026 | 44.0% | 19,017 |
| 19 Oct 2026 | 44.1% | 19,095 |
| 18 Oct 2026 | 44.3% | 19,173 |
| 17 Oct 2026 | 44.5% | 19,233 |
| 16 Oct 2026 | 44.7% | 19,320 |
| 15 Oct 2026 | 44.9% | 19,406 |