Relief and hydrography

The mean elevation of the Sava River Basin is approx. 545 m a.s.l. varying between 2,864 m a.s.l. in Triglav, on the Julian Alps in Slovenia to approx. 70 m a.s.l. at the mouth of the Sava River in Belgrade, Serbia. High mountains, the Alps and the Dinarides, dominate in Slovenia, southern part of Croatia, Bosnia and Herzegovina, and in particularly rugged terrain in Montenegro and Northern Albania where average elevation is more than 2,000 meters a.s.l with occasional exceedance of 2,500 meters a.s.l (the peak of Bobotov Kuk, Durmitor). Considerable part of the basin area is covered by forests while the northern part in the Pannonian Plain is characterized by the fertile agriculture land. 

The Sava River is formed by the two mountainous streams: the Sava Dolinka (left) and the Sava Bohinjka (right). In the length of 945 km (together with its longer headwater, the Sava Dolinka River has lenght of 990 km), the Sava flows in a NW-SE direction through Slovenia, Croatia, Bosnia and Herzegovina and Serbia, in some part creating the border between Slovenia and Croatia, Croatia and Bosnia and Herzegovina, as well between Bosnia and Herzegovina and Serbia. 

The course of the Sava River can be divided in the 3 sections: 
  • Upper Sava, from the confluence of Sava Dolinka and Sava Bohinjka to the confluence of the river Rugvica (km 658, measured from the Sava River mouth), comprises mountainous and hilly relief; 
  • Middle Sava, from Rugvica and the confluence of the Drina River (km 178) is a lowland, alluvial section, characterized by wide floodplains, and mouths of the numerous tributaries; 
  • Lower Sava, downstream of the Drina River mouth is alluvial section with no significant tributaries. The most downstream part of the Sava River in length of 100 km is under the influence of the Danube River. 
Common feature of almost all right tributaries of the Sava River is their torrential behavior, particularly in their upper sections while left tributaries (except in Slovenia) which drain mostly flat areas and low hills of the Pannonian Plain are characterized with lower slopes and flow velocities, smaller and meandering streams.