Numedalslågen

Numedalslågen is a river in southeastern Norway that flows through the counties of Vestfold, Telemark, and Viken. It is one of Norway's longest rivers.

Numedalslågen runs for over 250 kilometers (160 miles) through the counties of Vestfold, Telemark, and Viken, beginning on the Hardangervidda plateau and ending at Larvik in Vestfold. Numedalslågen is one of the longest rivers in Norway. The river flows through Larvik, Lardal, Kongsberg, Flesberg, Rollag, and Nore og Uvdal. These municipalities work together in the administration and use of river resources in various projects under the Green Valley (Grønn Dal) umbrella.

In the higher range of Numedalslågen, there are a number of hydroelectric plants. Except for the stretch between Hvittingfoss and Larvik and Godfarfossen in Dagali, the majority of the main river's power potential has been developed.

The first power plant built in the Nore municipality in Viken, Nore I kraftverk, used Norefallene between Tunhovdfjorden and Rødberg. It was designed by Norwegian architects Carl Buch and Lorentz Harboe Ree and completed in 1928. The Nore II kraftverk, which was completed in 1947, uses the drop between Rødberg dam and Norefjord.

Numedalslågen is well-known for its salmon fishing, but a parasite known as Gyrodactylus salaris has recently been discovered in the area, potentially endangering the salmon stock. Other fish species found in Numedalslågen include trout, eel, and pike.

Length: 250 km (160 mi)