The river Baltoji Ancia flowing in Lazdijai district, the river Nemunas left tributary. Length of the river 60 km, the catchment area 791 km ². Source 4 km W. from Seirijai at the highway to Lazdijai. Flowing to S. through the lakes Vernijas, Ancia. From Kapciamiestis town flowing to SE. The river flows into the river Nemunas 466 km from its mouth, above Simoniskes. Riverbed width of the upper section 8-12 m, 15-20 m lower section. Average depth from 0.8 to 1.5 m. Average gradient 94 cm / km. Average width of valley 300-500 m, slope height to Guroniai village 10-15 m, 15-20 m below. Runoff controls the lakes. Spring flood ranges in height approx. 1 m. Current speed from 0.3 to 0.5 m / s. Rated discharge at the mouth: max. 20 m³ / s, avg. 5 m³ / s, min. 1.7 m³ / s.

All year.
Shallows, rapids, strainers, dam.
WW 0. From Baltoji Ancia HPP dam 1+.

39.6 Veisiejai. The bridge over the lake Ancia isthmus.
36.2 right hillfort Meciunai.
31.2 The Baltoji Ancia flows out from south end of the lake Ancia. right Jiezdas. About half a kilometer the Ancia flowing between the reeds. To Kapciamiestis town some shallows. Many footbridge. Average gradient to Petrakiai 75 cm / km.
30.1 The Ancia 100 m passes through the small lake overgrown by reeds.
29.2 left Dumbliauskai. left the lake Ragazis.
26.4 Bridge. Kapciamiestis.
25.7 Bridge. Kapciamiestis.
24.4 right Nieda. 30 m downstream the bridge. Kapciamiestis. The river slowly winds through forests.
21.8 left Pertakiai. Average gradient to the river Neviede 71 cm / km.
17.8 right Menciskes.
15.6 Small bridge. left Menciskes.
14.5 right Menciskes.
11.8 left Neviede. Begins the Baltoji Ancia pond. The pond looks like a wide river, at the banks pine forests.
8.7 right Maceviciai.
4.4  Baltoji Ancia HPP dam. Dam height 12 m, the pond area 250 hectares. right Baltoji Ancia. Average gradient to the mouth 97 cm / km. To the mouth small rapids, at the banks forests. Paddling downstream required border guards permit.
0.1 Wooden bridge. right Sventojanskas.
0.0 The Baltoji Ancia flows into the river Nemunas. Here goes Lithuania - Belarus border.