On 19 June the Vistula River caught a break. The Provincial Administrative Court in Warsaw dismissed the appeal filed by the state-owned investor, Polish Waters (Wody Polskie), against the negative environmental decision for the Siarzewo dam.
For the Vistula’s defenders, it is a victory—but the legal battle is not entirely over.
The verdict
The hearing concluded with the court upholding the decision made by the General Directorate for Environmental Protection (GDOŚ) in January 2025 to revoke the project’s environmental permit.
Over eight years of legal battles
To understand the importance this ruling, it helps to look at the history of this project. The battle began in 2017, when the first environmental permit was issued. Since then, OTOP (BirdLife Poland) and other NGOs have been locked in a legal fight.
For seven years, they filed appeals. Finally, in January 2025, the GDOŚ accepted the NGOs’ arguments, reversing the original decision and refusing to approve the environmental permit.
Instead of accepting defeat, Polish Waters appealed to the Provincial Administrative Court. After 18 months of waiting, the court has now sided with nature. The Siarzewo dam was meant to be the first Polish structure of the controversial E40 waterway—a project that threatens to turn the last major free-flowing stretch of the Vistula into a stagnant reservoir.
The risks of the Siarzewo dam
Even as we celebrate this ruling, it is vital to remember why this project should not be built. Siarzewo dam is the most expensive planned hydrotechnical project in Polish history, with costs estimated at 10 billion PLN.
If constructed, it would:
- destroy the Vistula’s natural dynamics, turning a wild, dynamic river with sandbars and floodplains into a stagnant reservoir;
- wipe out critical habitats, devastating the homes of endangered species, including the little tern and the Atlantic salmon;
- threaten protected areas, causing irreversible damage to three Natura 2000 sites and disrupting the entire hydrological regime;
- waste public funds, spending billions on a project with no proven economic benefit, ignoring the shift toward sustainable rail transport and river restoration.
What happens next?
Is the dam dead in the water? Not yet.
Following the receipt of the written justification, Polish Waters still has the option to file an appeal with the Supreme Administrative Court. If they choose to do so, the legal process could continue for another two years.
‘This ruling is a relief for the Vistula, but we are under no illusions that the fight is won,’ says Save Polesia Campaign Coordinator Helen Byron. ‘Siarzewo dam is just one slice of the controversial E40 waterway — a megaproject that is being pushed through using salami tactics, one small piece at a time. It threatens both the Vistula and Polesia, Europe’s largest wetland wilderness. But we will keep fighting to protect Poland’s Queen of rivers.’
The Vistula is safe for now. But our vigilance continues.
Further information
- Read the Frequently asked questions about E40 waterway
- Read OTOP’s (BirdLife Poland) article in Polish “Decyzja GDOŚ ws. stopnia wodnego w Siarzewie”
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*Top image: the Vistula river. Photo credit: Marek Elas