About Basin

Sava River is the third longest and the largest by discharge tributary of the Danube River. The length of the Sava River from its main source in western Slovenian mountains to its mouth to Danube in Belgrade is about 944 km. 
It runs through four countries (Slovenia, Croatia, Bosnia and Herzegovina, and Serbia), and connects three capitals of these four countries: Ljubljana in Slovenia, Zagreb in Croatia, and Belgrade in Serbia. The fourth capital – Sarajevo, in B&H, also belongs to the Sava River Basin.

The basin, with the area of 97,713 km2, covers considerable parts of Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro and a small part of the Albanian territory (Table 1). 


Table 1. Main figures on the Sava River Basin

Country Country share

Country share
 Slovenia  11,734.8  12.0
 Croatia  25,373.5  26.0
 Bosnia and Herzegovina  38,349.1  39.2
 Serbia  15,147.0  15.5
 Montenegro  6,929.8  7.1
 Albania  179.0  0.2
 Total  97,713.2  100.0

With its average discharge of about 1,564 m3/s, the Sava River represents the most important Danube tributary, contributing with almost 25% to the Danube's total discharge at their meeting point, in Belgrade. Therefore, sustainable management of the Sava River Basin has a considerable influence on the Danube River Basin area.

Sava River is very important for the Danube River Basin also for its outstanding biological and landscape diversity. It hosts the largest complex of alluvial wetlands in the Danube Basin (Posavina - Central Sava Basin) and large lowland forest complexes. The Sava River is a unique example of river with some of the floodplains still intact, thus supporting the flood alleviation and biodiversity.

Four Ramsar sites, namely Cerkniško jezero (Slovenia), Lonjsko Polje (Croatia), Bardača (B&H) and Obedska Bara (Serbia) have been designated in the Sava River Basin. It also includes a numerous Important Bird and Plant Areas, protected areas at the national level and Natura 2000 sites.

Concerning the navigation capacity, the Sava River is, nowadays, navigable for large vessels up to Slavonski Brod (km 377) and for small vessels up to Sisak (km 583).

The basic information on the main tributaries of the Sava River is given in Table 2. 

               Table 2. The 1st order tributaries of the Sava River
River name Confluence Basin Length Countries Share of basin
- (l-left r-right) [km²] [km] - [km²]
Ljubljanica r 1,860.0 41.0 SLO
Savinja l 1,849.0 93.9 SLO
Krka r 2,247.0 94.6 SLO
Sotla/Sutla l 584.3 88.6 SLO, CRO SLO - 450.8 km²; CRO - 133.5 km²
Krapina l 1,244.0 65.6 CRO
Kupa/Kolpa r 10,225.6 297.2 CRO, SLO CRO - 8,412.0 km²; SLO - 1,101.0 km²; B&H - 712.6 km²
Lonja l 4,286.1 82.8 CRO
Ilova l 1,815.7 100.3 CRO
Una r 9,828.9 214.6 B&H, CRO B&H - 8,142.9 km²; CRO - 1,686.0 km²
Vrbas r 6,273.8 249.7 B&H
Orljava l 1,615.7 99.5 CRO
Ukrina r 1,504.0 80.7 B&H
Bosna r 10,809.8 281.6 B&H
Tinja r 904.0 99.4 B&H
Drina r 20,319.9 346.0 B&H, MON, SER, ALB B&H - 7,118.9 km²; MON - 6,929.8 km²; SER - 6,092.2 km²; ALB - 179.0 km²
Bosut l 2,943.1 / CRO, SER CRO - 2,375.0 km²; SER - 568.1 km²
Kolubara r 3,638.4 86.6 SER