Open water-data platform · 10 countries
Reservoir water levels, worldwide
Live storage and fill levels for 1,990 reservoirs, drawn from official hydrological sources across 10 countries — checked daily.
10
Countries tracked
1,990
Reservoirs tracked
51.0%
Global average fill
179
At critically low levels
1,362 km³
Combined capacity
Updated Jun 12, 2026 · 1,803 reservoirs reporting
Reservoirs.EARTH tracks how full the world’s reservoirs are. We collect official storage readings from national hydrological agencies and turn them into clear, comparable fill levels, multi-year trends and seasonal context — so anyone can see, at a glance, whether a dam is filling up or drying out. Every figure links back to its source, and we check for new official readings every day.
Countries covered
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MITECO official data
Spain
Average fill
82.4%
401 reservoirs
SNIRH official data
Portugal
Average fill
85.0%
51 reservoirs
USGS NWIS data
United States
Average fill
65.9%
481 reservoirs
ONS official data
Brazil
Average fill
43.7%
102 reservoirs
CWC official data
India
Average fill
34.7%
304 reservoirs
DWS official data
South Africa
Average fill
98.0%
218 reservoirs
IRSA official data
Pakistan
Average fill
50.8%
3 reservoirs
BOM official data
Australia
Average fill
58.2%
281 reservoirs
XM data · energy (GWh)
Colombia
Average fill
73.7%
24 reservoirs
NVE data · energy (TWh)
Norway
Average fill
51.7%
5 price areas
Right now around the world
Sizeable reservoirs with a reading in the last 30 days.
Lowest levels
Closest to empty
Reservoir Transparency Index
How openly does your country publish its water data?
We scored 194 countries on the openness of their reservoir reporting. See the rankings, grades and methodology.
Built on official data
Every reading comes from a national hydrological authority — never estimated or crowd-sourced.
From The Reservoir
All articles →Jun 10, 2026 · 7
The perfect score: what it would take for a country to reach 100/100 on the RTI
No country scores 100 on the Reservoir Transparency Index — Norway leads at 89.3. A perfect score isn't about having the most water; it's seven concrete things, and every one of them is already done by some country today.
Jun 2, 2026 · 5
Introducing the Reservoir Transparency Index: H1 2026
The inaugural, semi-annual ranking of how openly countries publish their reservoir storage data. The H1 2026 edition evaluated 194 countries — and the median one scores F.
Jun 1, 2026 · 5
Strategic withholding: when reservoir data becomes a diplomatic weapon
Egypt hides Aswan storage from public view. Ethiopia keeps GERD opaque. Kyrgyzstan actively pulled Toktogul data in 2025. The pattern is consistent: upstream-downstream tension produces deliberate opacity.
Frequently asked questions
How often is the data updated?
We check every official source daily, but each agency publishes at its own pace — some daily (e.g. the USGS and Australia’s BOM), others weekly (e.g. India’s CWC and South Africa’s DWS). The exact date of the latest reading is shown on every reservoir page.
Where does the data come from?
National hydrological and energy agencies: USGS (United States), MITECO and embalses.net (Spain), ONS (Brazil), CWC (India), DWS (South Africa), IRSA (Pakistan), the Bureau of Meteorology (Australia), SNIRH (Portugal), XM (Colombia) and NVE (Norway).
What does the fill level percentage mean?
It is the share of a reservoir’s total capacity currently in storage. 100% means full; below about 20% is considered critically low.
Which countries are covered?
Spain, Portugal, the United States, Brazil, India, South Africa, Pakistan, Australia, Colombia and Norway — with more being added over time.
Is reservoirs.earth free to use?
Yes. It is an open platform and every figure links back to its official source. You can also embed our Reservoir Transparency Index widgets.