(Pregel’ or Pregol’), a river in Kaliningrad Oblast, RSFSR.
The Pregolia River is 187 km long and drains an area of 15,500 sq km. It is formed by the confluence of the Angrapa and Pissa rivers, and it empties into the Vistula Lagoon of the Baltic Sea. The Pregolia is fed primarily by snow. High water is in spring, in March and April, and low water is in summer and fall. The mean flow rate is 90 cu m per sec. The river is linked with the Neman River by the Deima River, a canal, and the Matrosovka arm of the Neman. The river is also linked with the city of Baltiisk by the Kaliningrad Drainage Canal. The Pregolia is navigable from the city of Cherniakhovsk. The city of Kaliningrad is at its mouth.