Nidelva (Aust-Agder)

Nidelva (Aust-Agder)
Nidelva near Blakstad in Froland
Origin	Haugsjåsund, Telemark
Mouth	Arendal, Aust-Agder
Basin countries	Norway
Length	210 km (130 mi)
Basin area	4,000 km2 (1,500 sq mi)

This article is about the river in Aust-Agder, Norway. For the river which runs through Trondheim, see Nidelva.

Nidelva in Aust-Agder is the main river in the Arendal drainage basin. It is formed by the confluence of two rivers, Nisserelva and Fyreselv. The river flows into the Skagerak at Arendal. The total length of the system is 210 kilometres (130 mi), the watershed covers 4,000 square kilometres (1,500 sq mi). Sixteen hydro-electric power stations are built along the river, making this one of Norway's most controlled drainage systems.

Salmon can be found 22 kilometres (14 mi) up the river, where the Evenstad power station is located. At Rygene, the average waterflow is 110 cubic meters per second (m³/s), but the highest recorded was in the autumn of 1987, with 1200 m³/s.

References

• Energilink.no entry on Evenstad power station (Norwegian)
• Comparing upriver spawning migration of Atlantic salmon Salmo salar and sea trout Salmo trutta A.G Finstad, F. Økland, E.B. Thorstad, T.G. Heggberget, Journal of Fish Biology, 2005

Coordinates: 58°24′59″N 8°44′25″E / 58.4165°N 8.7403°E / 58.4165; 8.7403