The project will remove two obsolete concrete dams in the Skjerva River to restore fish migration, natural sediment transport, and ecological connectivity in the Vigga-Randsfjorden catchment.
The Skjerva River is a tributary of the Vigga River in the Randsfjorden catchment, located in Gran municipality, Innlandet county, Norway. The river flows through a mixed landscape of forest, agricultural land and floodplain areas, and has high ecological potential as a spawning and nursery river for brown trout and lake trout (Salmo trutta lacustris). Skjerva is directly connected to Lake Randsfjorden, one of the largest lakes in southern Norway, and plays an important role in the regional freshwater ecosystem.
Despite generally good natural conditions, two old concrete dam structures remain in the river. These were originally built for water supply and industrial purposes but have been out of operation for several decades. Today, they act as artificial barriers that disrupt longitudinal connectivity and natural river processes in an otherwise largely intact river system.
| Project status | Live |
|---|---|
| Project type | Dam removal |
| Country | Norway |
| River | Skjerva (tributary to Vigga, Randsfjorden catchment) |
| Removal timeline | 2026 |
| Km to be opened | 7.9 km |
| Focal species | Brown trout, Lake trout |
| Organisation | Dokkadeltaet National Wetland Centre (DNV) |
| Website | dokkadeltaet.no |
Although the Skjerva River is formally classified as having good ecological status, this assessment does not fully reflect on-the-ground conditions. The two obsolete dams are not registered in national water management databases, meaning their impact on fish migration and sediment transport has not been considered in the official status classification.
This creates a clear opportunity for ecological improvement. By removing infrastructure that no longer serves any societal function, the project can significantly enhance river connectivity and ecosystem function without trade-offs related to water supply, hydropower, flood control or cultural heritage. The project represents a cost-effective and low-conflict restoration opportunity, targeting a key pressure in the river system and contributing directly to improved ecological integrity at both local and catchment scale.
The main goal of the project is to restore longitudinal connectivity and natural river processes in the Skjerva River through the complete removal of two obsolete concrete dams. By eliminating these barriers, the project aims to re-establish free upstream and downstream migration for fish and other aquatic organisms and to restore natural sediment transport dynamics.
Removal of the dams is expected to open approximately 7.9 km of river upstream (including tributaries) and 5 km downstream, resulting in nearly 13 km of connected river habitat. This will significantly improve access to spawning and rearing areas for brown trout and lake trout, enhance benthic habitats, and support healthier population dynamics.
Additional expected outcomes include improved hydromorphological conditions, renewed supply of spawning gravel to downstream reaches, and increased ecological resilience of the river system. Social benefits include improved recreational fishing opportunities, strengthened local engagement with river restoration, and increased awareness of the benefits of removing obsolete river infrastructure.
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