The project will remove the remains of two obsolete mill dams on the Glāžupe River, restoring free fish migration, improving hydromorphological quality and reconnecting two Natura 2000 areas.
The Glāžupe is a right-bank tributary of the Salaca River, located in the Limbaži and Valmiera municipalities of the Republic of Latvia, with a length of approximately 19 km. It originates at the western edge of the Lielais Bog near the Estonian border.
The Glāžupe, like most other tributaries of the Salaca River, Latvia’s national salmon river, is suitable for the reproduction of anadromous species, mainly sea trout (Salmo trutta) and European river lamprey (Lampetra fluviatilis). The suitability of the river for these species is confirmed by the determination of the favourable reference value for protected fish species, based on habitat suitability modelling, within the LIFE project “Optimising the Governance and Management of the Natura 2000 Protected Areas Network in Latvia” (LatViaNature). Juvenile brown trout and lamprey larvae have also been found in the river.
| Project status | Live |
|---|---|
| Project type | Dam removal: demolition |
| Country | Latvia |
| River | Glāžupe |
| Km to be opened | 30 km |
| Removal timeline | February 2027 |
| Focal species | Sea trout, European river lamprey |
| Organisation | Dabas Izcilības Institūts (NINEX) |
| Website | Coming soon |
Fish migration and spawning in the river is impeded by two watermill dams, one located approximately 1.4 km from the mouth of the river and the other approximately 4.4 km from the mouth. The remains of both dams are obsolete, abandoned and partially collapsed, yet still impassable for migratory fish. They disrupt connectivity between the two Natura 2000 areas – Salaca Valley (LV0302200) and Northern Swamps (LV0000130) – and reduce the hydromorphological quality of the currently flooded river sections. Removing these barriers will address fragmentation in one of Latvia’s most important salmon rivers and support ecological recovery.
Both dams are included in the “TOP 70” Latvian fish migration barriers database. In addition to opening up approximately 30 km of rivers to fish migration in the Glāžupe and its tributaries and increasing the natural reproductive success of brown trout and river lamprey, several further benefits are expected.
Very few dams have been removed in Latvia so far and there are no established examples demonstrating the positive effects of dam removal. Since taimen and river lamprey colonise new habitats relatively quickly, it is likely that positive changes following the removal of these dams will encourage similar measures on other Latvian rivers in the near future.
Connectivity between the Natura 2000 areas Salaca Valley (LV0302200) and Northern Swamps (LV0000130) will be restored. The hydromorphological quality of the currently flooded parts of the river will improve, and with high probability the ecological status will shift from poor to good.
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