The river Plastaka flows in Moletai and Ukmerge districts, the river Siesartis right tributary. Length of the river 22 km, the basin area 105 km ². The source at Perkaliai village, 16 km northwest from Moletai town. Flows to southeast. Flows into the river Siesartis 17 km from its mouth at Antatilciai village. Average gradient 220 cm/km. Average rated discharge at the mouth 0.82 m³/s.

At high water level. Spring flood, or after heavy rains.
Rapids, shalows, strainers.
WW 1-/1 (2).

2.2 Zemaitkiemis - Valai road bridge. right Antatilciai. The river flows through small forest, width approx. 5 m. In the riverbed stones, buolders, small rapids, strainers, beavers dams.
1.0 The broken dam of former watermill. Width of the navigable rapid 1,5 m. Pedestrian bridge. right hillfort Antatilciai. The river is turning a large loop around the hillfort.
0.0 The Plastaka flows into the river Siesartis.