Nidelva (Agder)

Nidelva
Nidelva near Blakstad in Froland
Location of the river Show map of Agder Nidelva (Agder) (Norway) Show map of Norway
Location
Country	Norway
Counties	Agder, Telemark
Municipalities	Grimstad, Arendal, Froland, Åmli, Nissedal
Physical characteristics
Source	Confluence of Nisserelva and Fyresdalsåna rivers
• location	Haugsjåsund, Nissedal, Telemark
• coordinates	58°56′26″N 8°30′04″E / 58.9406°N 08.5011°E / 58.9406; 08.5011
• elevation	160 metres (520 ft)
Mouth	Skaggerak
• location	Arendal, Agder
• coordinates	58°26′06″N 8°42′49″E / 58.4349°N 08.7137°E / 58.4349; 08.7137
• elevation	0 metres (0 ft)
Length	221.7 km (137.8 mi)
Basin size	4,011 km2 (1,549 sq mi)
Discharge
• location	Rykene, Arendal
• average	114.4 m3/s (4,040 cu ft/s)
Basin features
River system	Arendalvassdraget
Tributaries
• left	Karlsåna, Katteråsåna
• right	Blekevja, Gjøv, Sigridneskilen, Songeelva, Trevann, Rore
Waterbodies	Nelaug
Waterfalls	Kastefossen

Nidelva is the main river in the Arendal drainage basin in Agder county, Norway. The 221.7-kilometre (137.8 mi) long river begins at the confluence of two rivers: Nisserelva and Fyreselv. The confluence is located by the village of Haugsjåsund in Nissedal municipality in southern Telemark county. The river flows south into the Skagerrak at the city of Arendal. The watershed covers 4,011 square kilometres (1,549 sq mi) and has an average waterflow of 114.4 cubic metres per second (4,040 cu ft/s) at Rykene near the mouth. The highest waterflow ever recorded on the river was 1,200 cubic metres per second (42,000 cu ft/s) in the autumn of 1987.