Abstract in the river Núpsvötn
Westernmost at Skeiðarársandur, Núpsvötn lakes are to be found. They are nourished by the rock stream Núpsá and the glacier river Súla. Súla flows down from the edge of Skeiðarárjökull glacier, at the corner of Eystrafjall mountain. The rivers merge into one river-bed some way above the bridge over Núpsvötn. When the main road was laid in 1974 both of the rivers were hindered with levees. In the first part of the 20th century, Súla-debacles from the lagoon Grænalón were massive, around 5-10 thousand m³/sec, and when Grænalón emptied the water level lowered about 150-200 m. These days it will only lower about 20 m and the quantity of water will peak at approx. 2000 m³/sec.