10 Largest Rivers in Iceland by Volume

Olfusa river, 423 m³/s

Thjorsa river, 370 m³/s

Kudafljot river, 250 m³/s

Jokulsa a Dal river, 205 m³/s (before the establishment of Karahnjukar hydroelectric dam)

Jokulsa a Fjollum river, 183 m³/s

Tungnaa river, 175 m³/s

Jokulsa í Fljotsdal river (Lagarfljot), 130 m³/s (before the establishment of Karahnjukar hydroelectric dam)

Skafta river, 122 m³/s

Skeidara river, 110 m³/s

Heradsvotn river, 108 m³/s

Sogid river, 108 m³/s