The river Pyvesa flows in Birzai, Kupiskis, Panevezys and Pasvalys districts, the river Musa right tributary. Length of the river 95 km, the basin area 500 km ². The source at Skiltuvai village, 10 km northwest from Pandelis town. Flows to southeast, in Pasvalys district turns to northwest. Flows into the river Musa 17 km from its confluence with the Nemunelis river 5 km to northeast from Pasvalys town. The riverbed to Pruseliai village (50 km to the mouth) channeled. Average gradient 65 cm/km. In upper section to the mouth of the brook Vijunite bottom silty, downstream sandy. In some places boulders in the riverbed. Rated discharge at Zadeikiai village (12 km to mouth): max 86.3 m³/s, average 2.80 m³/s, min in summer 0.10 m³/s, min in winter 0.030 m³/s. In spring the river drains 59%, in summer 5%, in autumn 13%, in winter 23% of the total annual volume of water. Spring flood lasts 20-30 days. The water rises 1-2 m, sometimes up to 2.5 m; water level height increases towards the mouth, and at the mouth of the affluent river Musa, is 3 m.

At higher water level. Spring, or after heavy rains.
Small rapids, shalows, strainers, water plants in summer.
WW 0 (1).

33.4 Kirklinai - Smilgiai road bridge. Moliunai. The river flows through meadows, width approx. 10 m. Current calm. At the banks trees and bushes. Average gradient to the brook Dvesiene 45 cm/km.
31.5 left Dalickai.
28.5 left Gudas. left Gustadalis.
27.0 Bridge. left Rinkunai.
24.1 Pumpenai - Daujenai road bridge. left Rinkunai. right Vizoriai.
22.2 left Dvesiene. Average gradient to the brook Orija 71 cm/km. The river flows throug forest. The current a bit accelerated. Can be strainers.
18.6 right Truliskis.17.1 right Uzusienis.
16.6 right Orija. left Zadeikeliai. The river flows through meadows. At the banks trees and bushes. The current accelerated, the river widening, to the mouth a few small rapids, shalows. Average gradient to the mouth 90 cm/km.
14.8 Bridge. right Pasile.
14.1 right Geivitoniai.
12.3 Pasvalys - Vabalininkas road bridge. Zadeikiai.
10.7 right Karautis. right Staciunai.
8.7 Bridge. right Kurkliskiai.
7.8 right Vingrys. left Siksneliskiai.
5.6 Pasvalys - Kiemeliai road bridge. right Kiemeliai. left Diliauskai.
3.9 right Krincinas.
3.6 Railway bridge.
3.3 Bridge. right Adampolis.
2.8 right Vidubala. Vilnius - Ryga highway bridge. right Papyvesiai. The current calms.
0.0 The Pyvesa flows into the river Musa.