Nidelva in Trondheim, view upstream
|Municipalities||Trondheim and Klæbu|
|- location||Klæbu, Norway|
|- elevation||157 metres (515 ft)|
|0 metres (0 ft)|
|Length||30 km (19 mi)|
|Basin size||3,118 km2 (1,204 sq mi)|
|- average||94 m3/s (3,300 cu ft/s)|
Nidelva is a river in Trøndelag county, Norway. The 30-kilometre (19 mi) long river travels through the municipalities of Trondheim and Klæbu. The name translates to the "River Nid" since the suffix elva or elven is the Norwegian word for "river".
The Nidelva starts at the Hyttfossen waterfall which rises from Bjørsjøen, a small lake located just below Selbusjøen, the largest lake in the southern part of Trøndelag County. The Nidelva runs north through Klæbu, then to Tiller, and then through the city of Trondheim before reaching Trondheimsfjord by the island of Brattøra near Trondheim Central Station. The Nidelva is at its deepest at the Trongfossen, a deep ravine in the village of Klæbu. There are six hydro-electric power stations along the river. The Nidelva forms the last part of the Nea-Nidelvvassdraget watershed. The Nea River is a tributary which empties into Selbusjøen, which in turn flows into the Nidelva.
The popular Norwegian waltz, Nidelven Stille og Vakker du er ("Nidelven quiet and beautiful you are"), was written by composer Oskar Hoddø (1916–1943). According to tradition, Hoddø wrote the waltz about the Nidelva River one night in late April 1940 while he was standing at Gamle Bybro in Trondheim.
- "Gamle bybro" (in Norwegian). Trondheim Havn.
- Olsen Haugen, Morten, ed. (2017-11-13). "Nidelva – Trøndelag". Store norske leksikon (in Norwegian). Kunnskapsforlaget. Retrieved 2018-03-12.
- Rosvold, Knut A., ed. (2010-10-17). "Neavassdraget". Store norske leksikon (in Norwegian). Kunnskapsforlaget. Retrieved 2018-03-12.
- Hoddø, Oskar (2002-11-01). "Nidelven stille og vakker du er". Trønderlag of America. Archived from the original on 2011-07-17.
- Øksendal, Asbjørn (1969). Lurøy-affæren - Operasjon Oleander: Gestapo i Trondheim og Leksvik-affæren 1942-44 (in Norwegian). Norge: Nordenfjelske forlag. ISBN 9788270050239.
- Media related to Nidelva, Trøndelag at Wikimedia Commons