CACU
Goiás · PARANAIBA
Useful capacity
31.69 hm³
Coordinates
18.532°S, 51.149°W
Operator
ONS
95.8% of useful capacity
Current fill
95.8%of useful capacity
vs 7 days ago
-3.1 pplosing
vs 1 year ago
+14.5 ppyear-over-year
7-day trend
↓falling
Drought context
Storage vs October average
108%of normal
95.8% full on 2026-10-26, against an average of 88.7% for October across 2 years of readings (+7.1 points).
Rain over the last three months · 11 October 2026
Near normal
In the three months to 11 October 2026 the area around CACU 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 +0.10). Rain, not storage. Brazil drought figures →
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Technical specifications
| Total capacity | 227.45 hm³ |
| Usable capacity | 31.69 hm³ |
| Primary use | Hydroelectric |
| Operator | ONS |
| River | CLARO |
| Province | Goiás |
| River basin | PARANAIBA |
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 18.532°S, 51.149°W · Open in Google Maps
About CACU
As of October 26, 2026, CACU is at 95.8% of useful capacity, holding 30.4 hm³ of 31.69 hm³. Of the 227.45 hm³ total capacity, that is 13.4%. At this level the reservoir is high.
Over the most recent week on record the fill level has fallen by 3.1 percentage points, and it is 14.5 points above its level on the same date a year earlier.
Across the readings we hold for CACU — 65 data points between October 26, 2025 and October 26, 2026 — the level has ranged from a low of 64.4% (February 20, 2026) to a high of 100.0% (April 10, 2026). On average the reservoir is fullest around September and at its lowest around February.
It is operated by ONS primarily for hydroelectric power. It lies within the PARANAIBA basin at 18.532°S, 51.149°W.
Key facts
- Current fill level
- 95.8% of useful capacity
- Water stored
- 30.4 hm³
- Total capacity
- 227.45 hm³
- Usable capacity
- 31.69 hm³
- 7-day change
- ▼ 3.1 pp
- Year-on-year
- ▲ 14.5 pp
- Primary use
- Hydroelectric power
- River
- CLARO
- River basin
- PARANAIBA
- Operator
- ONS
- Coordinates
- 18.532°S, 51.149°W
- Last updated
- October 26, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 26 Oct 2026 | 95.8% | 30.4 |
| 25 Oct 2026 | 99.0% | 31.4 |
| 24 Oct 2026 | 99.0% | 31.4 |
| 23 Oct 2026 | 95.8% | 30.4 |
| 22 Oct 2026 | 95.8% | 30.4 |
| 21 Oct 2026 | 94.8% | 30 |
| 20 Oct 2026 | 95.8% | 30.4 |
| 19 Oct 2026 | 99.0% | 31.4 |
| 18 Oct 2026 | 93.7% | 29.7 |
| 17 Oct 2026 | 90.1% | 28.5 |
| 16 Oct 2026 | 91.6% | 29 |
| 15 Oct 2026 | 97.9% | 31 |