The river Armona flowing in Jonava and Ukmerge districts, the river Sventoji right  tributary. Length 33 km, the catchment area 229 km ². Source near Tarakai village, 7 km southwest from Siesikai town. Flowing through Siesikai town and the lake Armona  to southeast. Flows into Sventoji 31 km from its mouth. Average gradient 139 cm / km. To Ukmerge - Kedainiai road the river valley blurred , banks low; below the valley width 30-80 m, the depth 5-8 m. Average discharge at the mouth 1.42 m³ / s, max. 27.5 m³ / s. In upper section of the river often dries out in the summer.

At high water level. Spring flood, or after heavy rains.
Shallows, rapids, strainers, dam.
WW 1+ (2-).

6.2  Kaunas - Ukmerge highway bridge. right Laibiskiai. The river runs through the meadows, on the banks overgrown with rare trees. Riverbed width 5 m.
4.5 Begins Dovydiskiai pond.
3.9  Dovydiskiai dam. Portage. left Dovydiskiai. The river begins to descend to the river Sventoji. The gradient is gradually increasing, banks climbing and compresses the river. The river flows through the meadows, on the banks overgrown with trees. In riverbed big stones, rapids, strainers. The riverbed width 6-8 m.
2.1 The river flows into the forest. The river gradient large, in riverbed large rocks, shoals, rapids, strainers (not very much), the current strong. The banks are steep.
1.5 right Pavarklas.
1.3 right tributary. Just before the mouth  the river flowing out of the forest,  the current calm.
0.0 The Armona flows into the river Sventoji.