The river Skroblus flows in Alytus county, Varena district, the river Merkys left tributary. Length of the river 17 km, the basin area 67 km ². The source at Margionys village near Vilnius - Grodno railway. Flows to north through Varena forests. The Skroblus flows into the river Merkys 11 km from its mouth at Trasnikas village, 8 km southeast from Merkine town. Average gradient 199 cm/km. Average rated discharge at the mouth 0.44 m³/s.

All year.
Shalows, strainers, low footbridges.
WW 0 (1-).

6.8 Bridge. left Rudnia. The brook meanders through forests. In some places not high sandy outcrops. The current fast. The river widh 3-5 m. Strainers. To Dubininkas village Skroblus reserve. For visits permits is needed.
3.3 left Bersibarka.
2.2 Bridge. left Dubininkas. The river wider, strainers, low footbridges.
2.0 Bridge.
0.0 The Skroblus flows into the river Merkys. Before the mouth low, not navigable, bridge. left Trasnikas.