Sutla

The Sutla (Croatian: [sûtla]) or Sotla (Slovene: [ˈsóːtla]) is a river flowing through Slovenia and Croatia, mostly forming their border. It is a tributary to the Sava, itself a tributary to the Danube. It is 89 kilometres (55 mi) long and has a watershed area of 584 square kilometres (225 sq mi).^[2]

Sotla / Sutla
Sutla River in Zelenjak, between Klanjec and Kumrovec
Location
Countries	Slovenia Croatia
Physical characteristics
Source
• elevation	580 m (1,900 ft) [1]
Mouth
• location	Sava
• coordinates	45°51′52″N 15°41′01″E
• elevation	135 m (443 ft) [1]
Length	88.6 km (55.1 mi)[2]
Basin size	584.3 km2 (225.6 sq mi)[2]
Basin features
Progression	Sava→ Danube→ Black Sea

Overview

The Sutla flows through the following municipalities:

• in Slovenia: Rogatec, Rogaška Slatina, Podčetrtek, Bistrica ob Sotli, Brežice
• in Croatia: Đurmanec, Hum na Sutli, Desinić, Zagorska Sela, Klanjec, Kraljevec na Sutli, Brdovec

The hydrological parameters of the Sutla are regularly monitored in Croatia at Zelenjak.^[3]

The division of the Sutla/Sotla basin area between Croatia and Slovenia is inconsistent in sources; Croatian sources claim either 343 km² (132 sq mi)^[4] or 455 km² (176 sq mi),^[5] while Slovenian sources claim either 477 km² (184 sq mi)^[6] or 451 km² (174 sq mi).^[1]

Kozje Park (Slovene: Kozjanski park), established in 1981 as Trebče Memorial Park (Spominski park Trebče), is located in Slovenian territory west of the Sotla. It covers 206 km² (80 sq mi) of the landscape of the Kozje Hills (Kozjansko hribovje), including wetlands along the Sotla. It is the habitat of over 120 bird species and of about 950 higher plant species.^[7]

The earliest known mention of Sutla was in 1028, as Zontla. The name is pre-Slavic in origin and comes from *Sǫtъla. The root *Sont-/*Sant- does not have a known meaning.^[8]