The river Musia flows in Vilnius county, Ukmerge district, the river Sventoji right tributary. Length of the river 31 km, the basin area 216 km ². The source at Balciai village, 11 km southeast from Raguva town. Flows to southeast. Flows into the river Sventoji 50 km from its mouth at Kadrenai village, 7 km north from Ukmerge town. The river channeled. Average gradient 98 cm/km. Max rated discharge at the mouth 5.70 m³/s, average 1.69 m³/s.

At higher water level. Spring, or after heavy rains.
Rapids, shalows, dam, strainers.
WW 0/1 (2).

4.2 Kurenai - Jasiuliskiai road bridge. The pond of Kadrenai. right Toliunai.
3.4 right Musele flows from the lake Kurenai. left Pijorai.
1.8 The dam of Kadrenai HPP. Height 5 m, area of the pond 93 ha. Portage better left. right Kadrenai. Downstream the dam the river descends to the river Sventoji valley. The banks steep, high. The riverbed average widh 10m. Smal rapid, length 300 m.
1.5 Small rapid.
1.0 On the site of former watermill small rapid. Average gradient to mouth 480 cm/km.
0.7 Pedestrian bridge. To next bridge rapid.
0.65 Ukmerge - Utena highway bridge. Downstream the river flows through forest. Can be a few strainers. Small rapids.
0.0 The Musia flows into the river Sventoji. At confluence right hillfort Zujai (Santo Kalnelis).