The project carries out a detailed inventory and evaluation of all types of barriers in the Lom River, laying the groundwork for future dam removals to restore connectivity along the river.
Stretching 93 kilometres through northwestern Bulgaria, the Lom River is one of the country’s last largely untouched waterways. A tributary of the majestic Danube, it boasts near-pristine morphology and an exceptional ecological status. Its catchment area provides a refuge for rare and endangered species, making it a critical haven for biodiversity.
Among its waters thrive fish of high conservation value, including the Danubian longbarbel gudgeon (Romanogobio uranoscopus), Kessler’s gudgeon (Romanogobio kesslerii), Balkan loach (Cobitis elongata), Balkan golden loach (Sabanejewia balcanica), and stone loach (Barbatula barbatula), as well as a threatened mussel and crayfish.
The river’s middle and lower stretches are protected under national laws and the EU’s Natura 2000 network, safeguarding this ecological treasure for future generations.
| Project status | Completed |
|---|---|
| Project type | Barrier identification and prioritisation |
| Country | Bulgaria |
| River | Lom River |
| Focal species | Danubian longbarbel gudgeon (Romanogobio uranoscopus), Kessler's gudgeon (Romanogobio kesslerii), Balkan loach (Cobitis elongata), Balkan golden loach (Sabanejewia balcanica), stone loach (Barbatula barbatula), as well as a threatened mussel and crayfish. |
| Organisation | WWF Bulgaria |
The Lom River basin is heavily fragmented by numerous barriers, yet no public information exists regarding their number, ownership, status, or use. Barriers near the confluence appear abandoned in satellite images, with signs of deterioration accelerating over the past decade. These crumbling structures not only obstruct the natural flow of fish migration but also scatter the river with concrete debris, posing safety hazards and increasing flood risks by directing strong currents towards protective dykes.
Removing these deteriorating obstacles will restore the river’s connection to the Danube, reopening vital pathways for migratory fish and revitalising the biodiversity of both the Lom and the vast Danube basin.
A preliminary review of the short stretch of the Lom River near its mouth by the town of Lom, supported by satellite imagery, has identified numerous barriers in varying states of decay. These deteriorating structures block migratory fish pathways and increase flood risks for nearby villages, presenting urgent environmental and safety concerns.
This project aims to comprehensively assess the Lom River’s barriers and their impacts on both the river and the broader Danube basin. The key actions include:
By prioritising barriers for removal through a balance of ecological, social, and economic considerations, the project seeks to revitalise the Lom River and lay the groundwork for its collaborative, long-term stewardship.
The project aimed to assess the ecological, social, and technical feasibility of removing obsolete river barriers along the Lom River in northwestern Bulgaria.
Through comprehensive mapping and field assessments, 42 artificial barriers were identified, all located within protected Natura 2000 sites or other conservation areas. The structures vary in condition – from nearly destroyed to significant obstacles to fish migration. Two key sections with a high density of barriers were prioritised for detailed investigation: between Zamfir and Momin Brod and near Falkovets (Yanovets).
An ichthyological survey confirmed the presence of 22 fish species, including seven species of European conservation importance. However, two major barriers were found to critically fragment habitats and restrict migration, leading to depleted fish populations upstream. Stepwise removal, beginning from the river mouth, was identified as the most effective restoration strategy to reconnect the Lom with the Danube.
The socio-economic analysis revealed severe depopulation, weak local economies, and low dependence on the river barriers, most of which are abandoned and non-functional. Local communities expressed neutral or supportive attitudes towards barrier removal, indicating no significant social or economic risks.
A hydro-technical pre-feasibility study of two degraded weirs demonstrated that their removal is technically feasible, low-cost, and associated with minimal environmental impact. The expected long-term effect is the restoration of river flow, reduced habitat fragmentation, and improved hydromorphological conditions.
Overall, the project concludes that removing obsolete barriers along the Lom River is technically viable, socially acceptable, and ecologically necessary. It establishes a strong scientific and social foundation for future river restoration efforts, contributing to biodiversity recovery and improved resilience of the Danube basin.
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