Lagarfljót / Lögurinn

Lagarfljót is a glacial river flowing through the Fljótsdalshérað region in East Iceland. The river is approximately 140 km long, stretching from the sources of Jökulsá in Fljótsdal to its mouth in Héraðsflói. For centuries, it has been one of the most prominent natural features of the area and has played an important role in shaping both the landscape and local settlement.

Within Lagarfljót lies the lake Lögurinn, which is about 35 km long. Its depth reaches up to 112 meters, making it the second lowest point in Iceland. According to Icelandic folklore, the mysterious Lagarfljót Worm is believed to inhabit the lake, and stories of the creature have been part of the cultural heritage of East Iceland for generations.

The towns of Egilsstaðir and Fellabær are located along the banks of Lagarfljót. The river therefore holds both natural and social significance and has influenced settlement patterns and livelihoods in the region.

As a result of the Kárahnjúkar Hydropower Project, water from the river Jökulsá á Brú has been diverted into Fljótsdalur. This has affected both the flow and the color of Lagarfljót, drawing the attention of local residents and researchers alike.

In deep, biologically active lakes such as Lagarfljót, plant material that accumulates and decomposes on the lakebed can produce marsh gas. When released, this gas may rise to the surface in dark, curved plumes. Such natural phenomena, together with submerged rock ridges that cause unusual wave patterns, are believed to help explain the legends and sightings associated with the Lagarfljót Worm.

Lagarfljót is the third largest lake in Iceland by surface area; only Þingvallavatn and Þórisvatn are larger.

Source: See here
Image: Jón Ingi