The story of the visible and hidden water we share.
Explore the data
The same planet, mapped two ways — the rivers and lakes we see on the surface, and the aquifers hidden beneath. Switch between the two views, recolour by theme, and click any shape for its full story.
Surface: basin polygons from the TFDD Basin–Country dataset (Oregon State University). Underground: IGRAC/UNESCO Transboundary Aquifers of the World, 2025 edition. Pinch or ⌘-scroll to zoom.
Stories
Long-form visual journeys through the world's great shared basins and hidden aquifers — their legends, their history, their treaties, and what comes next.

Nineteen countries, four capitals, one river — and the densest web of water diplomacy on Earth.

A hidden sea beneath four countries — and one of the only aquifers on Earth with its own treaty.

Eleven countries, five thousand years of history, and a dam that redrew the politics of a continent.

Sixty million people downstream, a cascade of dams upstream — Asia's great test of sharing.

A lake that shrank by nine tenths, eight countries in its basin — and only four treaties between them.
A treaty signed in 1960 that survived three wars — the world's most-tested water agreement.
Fossil water that fell as rain when the Sahara was green, now shared by four desert nations.
← drag to browse · five stories at launch, more to come
The country lens
Pick a country and see every river basin it shares and every aquifer beneath its borders — straight from the TFDD register and the IGRAC 2025 map.
Cooperation, and its shadow
The same water that produces the world's densest record of cooperation produces a rising tally of conflict. Both are shown by decade: the diplomacy above, the disputes below.
Treaties signed · TFDD, 1820–2023
Water-conflict events · Pacific Institute, from 1900
The cooperation indicator
Every story in this atlas carries a cooperation status — a five-step composite built from three published, citable sources. It is a summary, not a verdict: conflict and cooperation often coexist on the same river.
High tension
Tension
Mixed
Cooperative
Strong cooperation
Water-related interactions between the countries, scored on the BAR intensity scale from the TFDD International Water Events Database.
Treaties, their scope, and river basin organizations — computed directly from the TFDD International Freshwater Treaties Database, 1820 to today. This leg also colours the map above.
Coverage by operational cooperation arrangements as reported under UN SDG indicator 6.5.2 — the only measure that also covers aquifers.
For most of the 426 shared aquifers, no cooperation assessment exists at all. That emptiness is one of this atlas's most important findings. Recent water-conflict incidents come from the Pacific Institute's Water Conflict Chronology — a running record of events where water was a trigger, weapon or casualty — shown inside stories as a separate "shadow record", a history rather than a verdict. Full method & data lineage →