Idrijca

Idrijca is a river in western Slovenia. It is a left tributary of the Soča (Isonzo) and plays a significant role in the hydrology and landscape of the Idrija region. The river's name is closely linked to the town of Idrija, which lies in its valley and has historically depended on the Idrijca for water supply and power.

Geography and course

The Idrijca originates in the western Slovenian hills and flows generally southwest through the Idrija Basin. It passes through or near several settlements, including the town of Idrija, and continues toward the Soča, where it joins the river near the settlement of Most na Suchi. The river and its valley feature a combination of forested slopes, karstic terrains, and shallow gorges, reflecting the varied geology of western Slovenia.

Hydrology and ecology

The Idrijca has cold, clear waters that support a range of freshwater species, including brown trout and marble trout in its upper and mid-reaches. The river hosts typical Alpine to sub-Alpine riverine ecosystems, with diverse invertebrates and riparian habitats along its length. Water quality is monitored as part of broader regional water-management programs.

Human activity and heritage

The Idrijca valley is part of a historically important mining region. The nearby Idrija mercury mine, a UNESCO World Heritage Site, reflects the area's industrial heritage and its long interaction with the river. In addition to mining, the river supports small-scale hydropower, local agriculture, and recreational activities such as fishing and hiking in the surrounding countryside.