Dams are not new. For millennia, humans have found ways to contain water in tanks and reservoirs in an effort to increase water supplies during dry periods.

A few things have changed in the past one hundred years or so, though. The magnitude of the dams we can build has increased, as has construction speed and, it would seem, our ambition to build more, larger dams.

The map below shows how dams developed between 1811 and 2011. Some dams were in place well before 1811 and are already on the map. Pale dams have no year recorded in the database and are shown for reference. Use the checkboxes to choose which dams to view.

Fisheries ||
Flood control ||
Hydroelectricity ||
Irrigation ||
Navigation ||
Other ||
Recreation ||
Water supply ||
No Data ||
No Year

Totals by Dam Type


The Global Reservoir and Dam (GRanD) Database is a project of the Global Water System Project. It contains records for 6862 dams and reservoirs (reservoirs not pictured here). Of those records, 408 have no year.

Who built this?