The river Siause flows in Siauliai county, Siauliai and Kelme districts, the river Dubysa left tributary. Length of the river 31 km, the basin area 152 km ². Flows out from the lake Rekyva. Flows to southwest. The Siause flows into the river Dubysa 104 km from its mouth, 10 km northeast from Kelme town. Average gradient 152 cm/km. Average rated discharge at the mouth 0.64 m³/s. In upper section the river channeled an damed in 2 places.

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

8.4 left Trinke.
8.2 bridge. left Gedvilaiciai. left Elbarai. Average rated discharge approx. 0.4 m³/s. Average gradient to the mouth 210 cm/km. Approaching the mouth the gradient and speed of the current gradually increases. In the riverbed small rapids, shalows, strainers.
6.8 right the brook S-2. right Gailaiciai.
4.7 left Durupis. The river discharge, garadient and speed of the current increases. In the riverbed small rapids, shalows, strainers, in some places boulders. The valley deep, the banks steep.
3.5 right Gembutiske.
0.0 The Siause flows into the river Dubysa. We recommend take out at the Kelme - Tytuvenai road bridge. (A 1.5 km downstream the river Dubysa).