How much water is in river Danube?

The Danube River is the second-longest river in Europe, after the Volga. It flows through ten countries, from Germany to Romania, and finally empties into the Black Sea. The average discharge of the Danube River is 6,500 cubic meters per second (m3/s). This means that, on average, 6,500 cubic meters of water flow through the Danube River each second. The total volume of water in the Danube River is approximately 180 billion cubic meters.