The river Kirsna flows in Lazdijai and Marijampole districts, the river Sesupe right tributary. Length of the river 44 km, the basin area 466 km ². The source at Palazdijai village, 4 km south from Lazdijai town. Flows to the northwest through the lakes Baltasis, Palazdijis, Rimietis. Flows into the river Sesupe 246 km from its mouth at Pasesupiai village. The river channeled, in summer in some places overgrown by water plants. Average gradient 86 cm / km. Average width of the riverbed 12 m. The bottom is sandy, silty locations only. On the banks many springs. Valley width downstream Lazdijai town 500 - 600 m. Average rated discharge at Nemunaiciai village (2.8 km to the mouth) 2.43 m³/s, at the mouth 2.80 m³/s.

All year.
Strainers, low footbridges, in summer water plants.
WW 0.

11.4 Kalvarija - Rudamina road bridge. right Ilgalauka. left Slabadele. The river channeled, width approx. 10 m. At the river meadows, the banks low, bare, in some places a few trees. Current calm. In summer in some places the river overgrown by water plants.
10.2 left Sliainiai.
9.2 left Mockavele.
8.6 left Senupe. Average gradient to the mouth 43 cm/km.
6.4 right the brook. right small forest.
6.0 dš.Jakimavičiai.
5.0 left Gasda.
4.7 Small bridge. left Tabarauskai. right Butanaviciai.
4.0 Small bridge.
3.5 Mikaliskiai.
2.9 Sestokai - Kalvarija road bridge. left Pakirsniai. right Ivantiskiai. At the banks rare trees and bushes.
1.7 right Zapalimai.
0.4 left Barauskai.
0.0 The Kirsna flows into the river Sesupe. right Barauskai.