Nea-Nidelvvassdraget is a watercourse in the municipalities of Tydal, Selbu, and Trondheim in Trøndelag county, Norway. The total area of the watershed is 3100 km2 and it runs for about 160 km 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 2581 GWh. Development of the area had already begun in 1890 with the development of the Øvre Leirfoss power station. Important rivers in the Nea-Nidelvvassdraget watercourse are the Nidelva, Nea, Rotla, Lødølja, and Tya. Amongst the biggest lakes are Sylsjön, Nesjøen, Stugusjøen, Finnkoisjøen, and Selbusjøen.