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TIETE
HighHydroelectric

PROMISSÃO

São Paulo · TIETE

Capacity

7,408 hm³

Coordinates

-21.297°N, 49.783°W

Operator

ONS

Current fill

97.5%
High

vs 7 days ago

-0.2%

losing

vs 1 year ago

+22.5%

year-over-year

7-day trend

stable

Catchment Weather

Past 30 days + 14-day forecast · Open-Meteo

Technical specifications

Total capacity7,408 hm³
Usable capacity2,127.3 hm³
Primary useHydroelectric
OperatorONS
RiverTIETÊ
ProvinceSão Paulo
River basinTIETE
Data source:ONS – Operador Nacional do Sistema Elétrico·Last reading: 2026-06-10

Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. -21.297, -49.783 · Open in Google Maps

About PROMISSÃO

As of June 10, 2026, PROMISSÃO is filled to 97.5% of its total capacity, holding roughly 2,074 hm³ of water out of a maximum 7,408 hm³. At this level the reservoir is high. Of that total, about 2,127 hm³ is usable (live) storage.

Over the most recent week on record the fill level has held broadly steady (-0.2 pts), and it is 22.5 points above its level on the same date a year earlier.

Across the readings we hold for PROMISSÃO — 52 data points between June 27, 2025 and June 10, 2026 — the level has ranged from a low of 40.6% (October 31, 2025) to a high of 98.5% (May 15, 2026). On average the reservoir is fullest around May and at its lowest around October.

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
97.5%
Water stored
2,074 hm³
Total capacity
7,408 hm³
Usable capacity
2,127 hm³
7-day change
▼ 0.2 pts
Year-on-year
▲ 22.5 pts
Primary use
Hydroelectric power
River
TIETÊ
River basin
TIETE
Operator
ONS
Coordinates
21.297°S, 49.783°W
Last updated
June 10, 2026

Recent readings

DateFill levelVolume (hm³)
10 Jun 202697.5%2,074
5 Jun 202697.8%2,080
29 May 202697.3%2,069
22 May 202698.3%2,090
15 May 202698.5%2,096
8 May 202698.0%2,085
1 May 202697.5%2,074
24 Apr 202697.5%2,074
17 Apr 202696.8%2,059
10 Apr 202696.0%2,043
3 Apr 202695.5%2,032
27 Mar 202695.0%2,022

Frequently asked questions

What is the current water level of PROMISSÃO?

As of June 10, 2026, PROMISSÃO is at 97.5% of its capacity, holding approximately 2,074 hm³ of water, according to ONS – Operador Nacional do Sistema Elétrico data.

Is PROMISSÃO reservoir full?

PROMISSÃO is essentially full, sitting at 97.5% of capacity as of June 10, 2026.

Is the water level at PROMISSÃO rising or falling?

The level at PROMISSÃO has been broadly stable over the latest week on record (-0.2 points).

How much water can PROMISSÃO hold?

PROMISSÃO has a total capacity of 7,408 hm³, of which about 2,127 hm³ is usable storage.

Where is PROMISSÃO reservoir located?

PROMISSÃO is located in São Paulo, Brazil, within the TIETE basin (coordinates 21.297°S, 49.783°W).

What is PROMISSÃO used for?

PROMISSÃO is used primarily for hydroelectric power, and is managed by ONS.

Nearby reservoirs

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