The Soča River basin of Slovenia.

picture: Satellite view of the Soča River Basin, with fishable waters in Slovenia outlined.

Rivers and streams.

The Slovenian part of the Soča River Basin offers a rich variety of fishable rivers and streams, ranging from calm spring-fed creeks to wild alpine torrents and remote gorges—all surrounded by stunning natural scenery. The waters are well-managed and host healthy populations of native trout species.  

Soča River.
The Soča River is managed by three entities:

• From the Italian border to just below the Doblar Hydroelectric Plant, where the Vogršček joins, it is managed by RD Soča.
  
• From this point upstream to the bridge near Bovec, the river is under the care of RD Tolmin.
  
• The headwaters, upstream from that bridge, are managed by the ZZRS (Fisheries Research Institute of Slovenia).
  

The river is inhabited by rainbow trout, marble trout, Adriatic grayling and the occasional brown trout or hybrid. 

Vipava River.
The Vipava is the first major tributary of the Soča in Slovenia and is managed by two fishing families:

• From the Italian border to a small dam near Brje, it is managed by RD Renče.
  
• Upstream from the dam to the town of Vipava, management falls under RD Ajdovščina.
  

This river primarily holds marble trout, rainbow trout, hybrids and the occasional brown trout.

hubelj.
The Hubelj is a cold, spring-fed river that joins the Vipava in the town of Ajdovščina. It is managed by RD Ajdovščina. The river is known for holding marble trout, rainbow trout, hybrids and brown trout. Only a small part of the river is open for fishing from it's mouth up to the highway bridge south of Ajdovščina.

Idrijca.
The Idrijca is one of the most prominent tributaries of the Soča River and a well-known destination for fly fishers in Slovenia. The river is managed by two fishing families:

• The lower section, from the confluence with the Soča upstream to the wildlife boundary near Stopnik, is managed by RD Tolmin.
• The upper section, from that point to the swimming area bela, is managed by RD Idrija.

The Idrijca is renowned for its marble trout, rainbow trout , Adriatic grayling, and marble/brown trout hybrids. It even has a remaining brown trout population. Both RDs maintain well-regulated fishing regimes, and the river features a mix of deep pools, fast runs, and gorges—ideal conditions for salmonids.

Bača.
A tributary of the Idrijca, the Bača flows through a picturesque valley and offers great opportunities for targeting marble trout and rainbow trout. It is managed by RD Tolmin.

Kneža.
The Kneža stream is a small but productive tributary of the Bača, also under the care of RD Tolmin. It holds marble trout, hybrids, and is valued for its clear waters and quiet environment.

Koritnica (Bača tributary).
Not to be confused with the Koritnica near Bovec. This branch, flowing into Bača, is managed by RD Tolmin. The banks of the Koritnica are densely covered with trees, and its flow is fast. It holds marble trout and hybrids.

Trebuščica.
The Trebuščica is a tributary of the Idrijca and the valley through which it flows is narrow, but numerous small gravel banks allow passage along deep pools and past cascades and rapids. It is considered one of the most beautiful rivers in the RD Tolmin area. but the fish populations are low at the moment. a few marble trout and escaped rainbow trout can be found here. it's head waters are protected and not fishable.

Cerknica.
The Cerknica is a tributary of the Idrijca that flows through Cerkno. Its managed by RD Idrija, and home to brown trout, rainbow trout, hybrids and marble trout.

Kanomljica.
The Kanomljica is a tributary of the Idrijca. Its managed by RD Idrija, and home to brown trout, rainbow trout, hybrids and marble trout.

Tolminka.
The Tolminka has carved its path toward the Soča through a narrow valley, at times forming a wild gorge, which is most beautiful in the area of the famous Tolmin Gorges. After passing through the gorges, the Tolminka descends into the Tolmin basin. RD Tolmin manages the waters and it hold marble trout and rainbow trout.

Učja.
The Učja flows in from Italy and covers a 6.1-kilometer course before joining the Soča. It is a fast alpine river with very difficult access. To fish this river a guide how knows the river is is must. it holds marble trout and hybrids and is managed by RD Tolmin.

Reka Idrija.
Reka Idrija is a small stream on the border with Italy managed by RD Soča. you can find marble trout, rainbow trout, and some hybrids here.

Nadiža.
The Nadiža originates in Italy and, after an 11.9-kilometer course, it returns there as well. Up to Pod Sedlo, it is hidden in a narrow valley full of rapids and deep pools. Managed by RD Tolmin, this warmer, crystal-clear stream is popular with anglers and swimmers alike. Fish include rainbow trout, marble trout, hybrids, and occasionally grayling.

Bela.
the Bela is a tributary of the Nadiža. Its riverbed was almost entirely regulated in the 1930s and divided by variously sized barriers. Deep pools formed below these barriers, and gravel shallows above them but it has been restored a bit. you can find rainbow trout, marble trout, hybrids and the occasional grayling here. 

Koritnica.
The Koritnica near Bovec is managed by the ZZRS. The river runs through a dramatic alpine gorge and offers a remote fishing experience in a pristine setting. It is inhabited by marble trout, the occasional Adriatic grayling, and hybrids. it's head waters used to hold one of the 8 pure populations of marble trout that were found but due to a landslide this populations was extirpated. luckily the gens of this population are still kept in the hatchery's.

Lepena.
The Lepena lays in a beautiful valley and its head waters in a forest has stunning waterfalls.
the fish population in this river is low due to some otters and the fish that are found here are hard to spot due to the colour of the rocks and gravel in this river. the river holds marble trout and rainbow trout and its managed by the ZZRS   

Fishing Families.

In Slovenia, most rivers are managed by local Fishing Families (Ribiška družina), which are angling associations responsible for sustainable use, restocking, and rule enforcement. The only state-managed waters are overseen by ZZRS.
In the Soča Basin, the following fishing families are active:

• RD Ajdovščina.
• RD Idrija. (fly fishing only)
• RD Renče.
• RD Soča.
• RD Tolmin.  (fly fishing only)
• Plus ZZRS, which manages upper sections of the Soča and some research areas. (fly fishing only)

Regulations.

Fishing rules in Slovenia vary by managing organization. Before fishing, you must check the specific regulations and purchase a daily or seasonal permit for that stretch of water. Regulations typically define:

• Allowed species
  
• Fishing methods
  
• Bag limits
  
• Catch-and-release zones

Fishing seasons typically run from April to October, though some sections may have different seasonal restrictions. Always consult the official website of the managing RD or ZZRS before planning your trip.

Guides.

• Emerald Paradise Tours
• Fly Fishing Soča / Fishing‑Guides‑Slovenia
• Flyfishingodec
• Gušti Fly Fishing
• Lucky Luke
• Lustrik
• Rok Fly Fishing
• Slovenia Fly Fishing
• Slo Fly Fishing & Fly Tying
• Slo-fly
• Soča Fly
• Soča Trout
• SocaFishingGuide
• Urko Fishing Adventures