Nidelva (Agder)
General data
- Name: Nidelva (Agder)
- Water system: North Sea
- Water type: River
- Source: Nisserelva, Fyreselva
- Progression: Skagerrak -> North Sea -> Atlantic Ocean -> Planet Earth
- Climates: Temperate
- Continents: Europe
- Countries: Norway
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 HaugsjƄsund in Nissedal municipality in southern Telemark county.
The river flows south into the Skagerrak at the city of Arendal.