Numedalslågen

Numedalslågen is a river in Norway. It is considered to be the second longest river in Southern Norway. It is located in the Numedal valley which runs through the counties of Vestfold, Buskerud and Vestland. At 356 km long, it is of the longest rivers in Norway.

Location
Numedalslågen begins on the Hardangervidda plateau and it collects in the lake Nordmannslågen which flows into the lake Bjornefjorden before it flows into the main channel of the river. From the Bjornesfjorden, the main river stretches for over 250 km through the counties of Buskerud and Vestfold and then meeting the ocean at the Larviksfjorden at the town of Larvik. Numedalslågen is one of Norway's longest rivers, beginning in Eidfjord and then running through the municipalities Nore og Uvdal, Hol, Rollag, Flesberg, Kongsberg, and Larvik. These municipalities cooperate in the administration and use of resources connected to the river in various projects under the Green Valley (Grønn Dal) umbrella.

There are a number of hydroelectric plants in the higher range of Numedalslågen. Most of the power potential of the main river is developed, except the stretch between Hvittingfoss and Larvik and Godfarfossen in Dagali. Nore I kraftverk, the first power plant built in the Nore og Uvdal municipality in Buskerud county used Norefallene between Tunhovdfjorden and Rødberg. It was completed in 1928 and was designed by Norwegian architects Carl Buch and Lorentz Harboe Ree. The Nore II kraftverk uses the drop between Rødberg dam and the Norefjorden and was completed in 1947.

Numedalslågen is known for being a good location for salmon fishing, although a parasite known as Gyrodactylus salaris has recently been found in Numedalslågen that may pose a threat to its salmon stock. Among the other fish species of Numedalslågen are trout, eel, and pike.

Name
The river is named after the Numedal valley (Nauma). The first element is nauma was the original name of the river. The meaning of that old name is unknown. The last element is which means "water" or "river".