Nea-Nidelvvassdraget is a watercourse in the municipalities of Tydal, Selbu, and Trondheim in Trøndelag county, Norway. The total area of the watershed is 3,100 square kilometres (1,200 sq mi) and it runs for about 160 kilometres (99 mi) from the source in the Sylan mountains to its mouth in Trondheimsfjorden. Trondheim Energiverk has fourteen power stations along the water course which are highly regulated, with a total production (in 2004) of 2,581 gigawatt-hours (9,290 TJ). Development of the area had already begun in 1890 with the development of the power station.