This river - a tributary of the right bank of the Neris. Another lake, Samanis is flowing out of the lake is in Ignalina district. Length of river - 250 km, the average annual runoff at the mouth - 55.1 m3/s, the average slope of - 0.51 m/km. Deepest river location - 1-2 m, in different sections is even deeper - up to 2.5-3 m, and shallow - 0.5-0.7 m with rifts rapids. In summer, the river bed is heavily overgrown with aquatic plants, but it can detect and clean it stretches. Šventoji has many tributaries - the largest tributary is Širvinta. In Zarasai district river flows through the area ​​40 km , most of which Gražutės Regional Park, Regional Park and Sartai southern part. Šventoji is one of richest of fishes rivers in Lithuania. In Šventoji resides fish species typical for rivers: the upper reaches - mainly roach, perch, pike, redeyes, middle reaches - chub, pike, roach, caught graylings, usor, to a lesser extent trout, perch, who will get the lower reaches. Catches can occur between asp, cods, eels and even a beard.