Sog (Icelandic pronunciation: ​[ˈsɔːx]; more commonly Sogið [ˈsɔijɪθ]) is a river in Iceland. It runs from the lake Þingvallavatn for 21.9 kilometres (13.6 mi) to its confluence with the river Hvítá, forming the river Ölfusá which then runs for another 25 km into the Atlantic Ocean. Its average discharge is 110 m3/s (3,900 cu ft/s). There are three hydroelectric power stations on the river: Ljósafossstöð [ˈljouːsaˌfɔssˌstœːθ] (15 MW), Írafossstöð [ˈiːraˌfɔssˌstœːθ] (48 MW) and Steingrímsstöð [ˈsteiːnˌkrimsˌstœːθ] (27 MW). The river runs through two lakes, Úlfljótsvatn and . * v * t * e