Abstract in the river Hverfisfljót. Hverfisfljót is one of the largest glacial rivers in the area and it originates at Síðujökull, a glacial tongue at the southwest of Vatnajökull glacier. Hverfisfljót divides the district into two regions: Síða, on the west side of the river, and Fljótshverfi on the east side. The river has very strong currents in places, and its water is dark grey and tumultuous, but the flow can vary greatly depending on the season. In summer, the average flow is 50–150 m³/sec, but it drops to 5–30 m³/sec in the winter. There are occasional outburst floods in Hverfisfljót, in conjunction with outburst floods from Skaftá river, with floodwater originating in the Skaftárkatlar cauldrons in Vatnajökull glacier.