Many Moons Back
The Soča River has been worshiped since ancient times. The name of its deity was Esontij. Aesontius. Discoveries, most of them from the Bronze Age, prove that the worship and offering to water deities were very important for the people living along rivers, including along the Soča. The oldest recorded name of the river, in Latin as Sontius or Isontius, dates to the 6th century.
On the Journey
Of all the rivers in Slovenia, the Soča has the shortest path to the sea, measuring 138* kilometres.
It gathers its waters in the heart of the Triglav National Park, in the mountains above Zadnja Trenta, before its first spring branch, the Potok (Creek), sparkles on the surface at an altitude of about 1300 metres on the Zapotok mountain pasture. The stream bravely runs through short troughs and smallish waterfalls, before disappearing into the often-dry stream called Suhi Potok (Dry Creek). Much more known and visited is the “official” source, emerging from the hole, the cave at 1000 metres ASL, immediately rushing through rapids and cascades toward the valley, where soon merging with the waters of the Potok. And so begins a journey one might wish to witness, like a fly on the ceiling of a room, where fascinating things are taking place.
The Soča river, Daughter of the Heights**
Besides its unique colour, the Soča is also known for its significant fluctuation in water volume, which rises considerably during snowmelt and heavy rains. What is the origin of its colour is a frequent and expected question, yet a simple and clear explanation is hard to find. It results from several factors, none of the explanation missing the involvement of the dissolved limestone and light reflection. Emerald, turquoise, green-blue, … The river’s captivating colour is both a magnet and a hallmark, drawing to the region the increasing numbers of domestic and foreign tourists, in search of different experiences, bringing with various challenges.
Its steep stream gradient, the cause of its lively temperament, and large amounts of rock, sand and very fine sediment traveling with it, allowed the Soča to carve picturesque troughs into rocky barriers. The easiest to admire are those is in the village Soča, at the border of the Triglav National Park near Kršovec, under the Napoleon Bridge in Kobarid, and beneath the bridge in Kanal, also a place of the traditional high-dives event happening there each August.
The Rich Biodiversity of the Soča Valley
The fast-flowing and frothy river is both cold and rich in oxygen. The former two are valued by those with paddles, the latter by fish. The queen of the upper and middle current of the Soča and some of its tributaries, is the endemic marble trout (Salmo (trutta) marmoratus), which can grow over a metre and as such weigh (over) twenty kilograms. Both, the marble trout and the Adriatic grayling (Thymallus aeliani), another autochthon species, have faced hard times due to war impacts, habitat loss, and the introduction of the invasive foreign species such as the brown (Salmo trutta fario) and the rainbow trout (Oncorhynchus mykiss), as well as the Danube type of the European grayling (Thymallus thymallus). However, experts successfully restored the autochthon fish population by introducing into the rivers the genetically pure fish, raised in hatcheries, and altogether is well appreciated by fly-fishermen who come to the Soča Valley from near and afar.
Following the locally born historian Simon Rutar, fishing in the Tolmin region began in early 14th century, while the bronze fishing hooks discovered in the burial sites of the Iron-Age-Sveta-Lucija, the small town nowadays known as Most na Soči, are even older. Interestingly, the same town is also the birth place of Marjan Fratnik, the author of the F-fly, the dry fly, as famous among fly-fishermen, as is the extreme section Katarakt among kayakers.
The world along the river is also rich in birdlife. To name just a few: the “diver” white-throated dipper (Cinclus cinclus), the dazzling pair, the Common kingfisher (Alcedo atthis) and the European bee-eater (Merops apiaster), and the exotic Greater flamingo (Phoenicopterus roseus) — which white, grey, or fiery red, depending on their diet — stride through the brackish wetlands at the river’s mouth near Tržič (Monfalcone). Attentive observers may also recognise the presence of larger animal friends of the river, leaving their tracks in the sand near the water, or in the moist ground of riparian forests. They come there to drink, hunt, or simply explore. Most often they are red (Cervus elaphus) and roe deer (Capreolus capreolus), but it’s not unusual to spot a chamois (Rupicapra rupicapra), wild boar (Sus scrofa), fox (Vulpes vulpes), or an otter (Lutra lutra). The flora is equally fascinating, especially the one growing on wide gravel bars, which in its own way “tells” how far upstream the Adriatic Sea “reaches”.
The River, a Source of Energy
The Soča’s natural course ends at the reservoir at Most na Soči, where it is joined with yet another bigger tributary, Idrijca, following the Koritnica, Boka, Učja, and Tolminka rivers which have already contributed their waters upstream. From its source to here, since 1976, the Soča and its tributaries are protected with a special legislation to preserve the biological characteristics of the water and the surrounding natural environment. Beyond this point and to the river’s mouth, there are seven hydroelectric dams, the first being built in Sagrado, Italy, in 1905. On Slovenian side, there are altogether five big and twenty-two smaller hydro powerplants, including those on tributaries.
In exchange for energy, the Soča flows altered. The system of the company Soške elektrarne produces 12.5% renewable energy in Slovenia. But Nature, it handles the situations its way. With river free flow being disrupted, one of the most mysterious fish species, the eel (Anguilla) has disappeared from these waters.
The Soča river, Isonzo
After winding between Sveta Gora (681 m ASL) and Sabotin (609 m ASL), passing under the world’s largest stone arch near Solkan, the Soča emerges from its final gorge and soon crosses the state border into a fertile plain, irrigated also by its waters. On the way across the Friulian plain, it is joined first by the Vipava (Vipacco) and later, near Turriaco, by the largest Venetian river, the Torre.
In the past, the Isonzo, as it is called on the path through Italy, flowed into the Gulf of Trieste in a wide delta, now “replaced” by orderly canals. The main one reaches the Adriatic Sea at Sdobba, within the Isonzo River Mouth Regional Nature Reserve (Riserva Naturale Regionale della Foce dell’Isonzo), a haven for birds, where already over 300 species have been recorded.
Here, coniferous and beech trees of the Trenta region give way to rustling reeds, and the crisp mountain air exchanges for thick and warm coastal one. The view is wider, unmistakably revealing the red-and-white chimney in Monfalcone, fishing boats in the canals, and cargo ships close and far on the see. Gone are the limestone mountain walls and green Alpine landscapes, but on a clear day, one can clearly see them, the whole range of white mountains, boasting there on the northern horizon. A perfect view for resting on the shore, inevitably adorned by the song of wildlife choirs.
May you remain splendid and graceful in your natural beauty** for many years to come. Soča.
Marjeta Albinini, Tolmin
Comments:
*Data on the length of the Soča River varies, ranging from 137 to 139 kilometres.
** Simon Gregorčič, To the river Soča (Soči)
Več:
Povž M., Jesenšek D., Berrebi P., Crivelli A. J. Soška postrv, Salmo trutta marmoratus, Cuvier 1817, v porečju Soče v Sloveniji. Tour du Valat: 1996
Rozman R. Soča od izvira do morja: veslaški vodnik. Kamna Gorica: Leeway Collective, 2024
Skoberne P. Sto naravnih znamenitosti Slovenije. Ljubljana: Prešernova družba, 1989
Tolminski muzej. Naplavine obsoške zgodovine: vodnik po stalni razstavi Tolminskega muzeja. Tolmin: Tolminski muzej. 2011
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