CACU
Goiás · PARANAIBA
Capacity
227.45 hm³
Coordinates
-18.532°N, 51.149°W
Operator
ONS
Current fill
88.5%vs 7 days ago
-1.6%losing
vs 1 year ago
-6.2%year-over-year
7-day trend
↓falling
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, -51.149 · Open in Google Maps
About CACU
As of June 10, 2026, CACU is filled to 88.5% of its total capacity, holding roughly 28 hm³ of water out of a maximum 227 hm³. At this level the reservoir is high. Of that total, about 32 hm³ is usable (live) storage.
Over the most recent week on record the fill level has fallen by 1.6 percentage points, and it is 6.2 points below its level on the same date a year earlier.
Across the readings we hold for CACU — 52 data points between June 27, 2025 and June 10, 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 July and at its lowest around September.
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
- 88.5%
- Water stored
- 28 hm³
- Total capacity
- 227 hm³
- Usable capacity
- 32 hm³
- 7-day change
- ▼ 1.6 pts
- Year-on-year
- ▼ 6.2 pts
- Primary use
- Hydroelectric power
- River
- CLARO
- River basin
- PARANAIBA
- Operator
- ONS
- Coordinates
- 18.532°S, 51.149°W
- Last updated
- June 10, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 10 Jun 2026 | 88.5% | 28 |
| 5 Jun 2026 | 90.1% | 29 |
| 29 May 2026 | 84.4% | 27 |
| 22 May 2026 | 88.5% | 28 |
| 15 May 2026 | 93.2% | 30 |
| 8 May 2026 | 85.9% | 27 |
| 1 May 2026 | 85.9% | 27 |
| 24 Apr 2026 | 79.7% | 25 |
| 17 Apr 2026 | 84.4% | 27 |
| 10 Apr 2026 | 100.0% | 32 |
| 3 Apr 2026 | 88.0% | 28 |
| 27 Mar 2026 | 92.2% | 29 |
Frequently asked questions
What is the current water level of CACU?
As of June 10, 2026, CACU is at 88.5% of its capacity, holding approximately 28 hm³ of water, according to ONS – Operador Nacional do Sistema Elétrico data.
Is CACU reservoir full?
No. As of June 10, 2026, CACU is high at 88.5% of its capacity, so it is not full.
Is the water level at CACU rising or falling?
The level at CACU is falling — it dropped 1.6 percentage points over the latest week on record.
How much water can CACU hold?
CACU has a total capacity of 227 hm³, of which about 32 hm³ is usable storage.
Where is CACU reservoir located?
CACU is located in Goiás, Brazil, within the PARANAIBA basin (coordinates 18.532°S, 51.149°W).
What is CACU used for?
CACU is used primarily for hydroelectric power, and is managed by ONS.