Ombla hydropower plant, Croatia
An underground hydropower plant is planned to be built in a natural habitat of global significance. The project’s assessments have been plagued by oddities and cannot be considered complete. In May 2013, following increasing pressure from civil society groups, the EBRD pulled out of the project for which it had approved a EUR 123 million loan.
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A protest action by Zelena Akcija against the Ombla power plant. Image by Zelena Akcija.
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Background
The Croatian electricity company HEP plans to build a 68 MW underground hydropower plant at a site which has been designated for protection as part of the EU’s Natura 2000 network of important natural areas.
The legality of the project is disputed as the Environmental Impact Assessment dates from 1999, contrary to Croatian legal requirements. The EBRD has approved a EUR 123 million loan for the project (November 2011) in spite of this, but withdrew from the project in May 2013. (See their response (pdf) to an open letter from civil society groups.)
With the loan, the project has lost most of its financing (the total costs are estimated with EUR 152,4 million) and thus its chances of going ahead are drastically reduced. Civil society groups led by Zelena akcija are calling on the Croatian government not to go ahead with the project.

It is obvious that the construction of a large underground dam will have serious impacts on the whole karst water system, which includes various channels whose exact routes and their links to one another are not well understood.
More details in an 2011 open letter from civil society groups to the EBRD
Impact on protected areas
The Ombla hydropower plant would be built in the vicinity of the Vilina Cave, near the spring of the Ombla river – a natural site of special significance:
- Underground karst rock formations that are associated to the spring contain a water system that runs for many kilometres through relatively soft and porous limestone rock.
- The area is home to a unique subterranean fauna: five species of protected bats; the fascinating proteus anguinus (sometimes known as the ‘human fish’ because of its flesh-coloured appearance) and several kinds of aquatic cave snails.
The importance of the area has also been recognised internationally:
- The spring and the karst rock formations will be a Natura 2000 site when Croatia joins the EU in 2013.
- Croatia’s underground fauna and the threats to it have already been covered by the BBC in its Newsnight programme.
HEP claims that the Vilina Cave itself will not be flooded. But it is obvious that the construction of a large underground dam will have serious impacts on the whole karst water system, which includes various channels whose exact routes and their links to one another are not well understood.
Illegal Environmental Impact Assessment
The project’s Environmental Impact Assessment dates from 1999, making it illegal under Croatian law. A Natura 2000 impact assessment has not yet been carried out.
Nonetheless, HEP, the Croatian government and the EBRD have rushed to get the project approved. (That a Natura 2000 biodiversity assessment is carried out is now a condition under the loan agreement.)
In response to this inexplicable hurry to approve the project before it meets EBRD standards, Zelena akcija has submitted an official complaint to the EBRD (pdf).
Farcical project assessment
The technical assessment of the project by the EBRD has been quite bizarre: French consultants Tractebel were hired by the EBRD to examine the project and wrote a rather critical report saying that the project was technically risky and financially and economically unfeasible:
Undertaking the project in full, as designed at present, carries a high risk of the project not achieving its objectives. (p.9-10)
The project fails to recover both investment outlays and recurrent costs, in fact yielding a considerable cost in commercial terms… the project could only be implemented if it was heavily subsidized by the government. (p.122-123)
The report furthermore stated that the project would only make a marginal contribution to the project’s declared aim of stabilising Dubrovnik’s electricity and water supply:
As the tourist season in Dubrovnik coincides with the dry season, the impact of Ombla on the development of tourism in terms of alleviating the water shortage and power deficit in summer time can be considered as peripheral. (p.127)
When the report was leaked to Croatian media and NGOs, HEP and the EBRD responded that it was only a draft (in spite of it being labelled “final”), that once the consultant had better understood the project the issues were solved.
People following the case have not been convinced by these claims.
Latest news
Activists help put the brakes on Balkan hydro projects
Bankwatch in the media | 27 August, 2015Balkan governments are under mounting pressure to curb the construction of hydropower plants (HPPs) in national parks and wildlife areas, where hundreds of projects are planned or underway. Environmental campaigners have already scored successes in halting new HPPs. In late July, Croatia’s environment ministry rejected Hrvatska Elektroprivreda’s impact study for its 68-MW Ombla HPP near historic Dubrovnik, Courts in Republika Srpska (RS) have twice this year backed activists’ claims that environmental assessments on proposed plants in the Sutjeska National Park were flawed.
Read moreGuest post: Croatia and the Energy Union: the European Commission’s unwarranted obsession with gas
Blog entry | 20 August, 2015Building the Energy Union, the European Commission pretends that all is well for renewables in Croatia and unnecessarily fixates on diversifying gas supply instead of managing demand.
Read more[Campaign update] Ombla hydropower plant nature impact assessment rejected
Blog entry | 10 August, 2015The Croatian Ministry of Environment and Nature Protection has refused Hrvatska Elektroprovreda (HEP)’s nature impact assessment for the Ombla hydropower project near Dubrovnik.
Read moreRelated publications
Official complaint to EBRD: Ombla hydropower project, Croatia
Official document | 17 November, 2011 | Download PDFMore information on the project is available here.
Questionable transition impact of the Ombla and Boskov Most hydropower plants
Advocacy letter | 4 November, 2011 | Download PDFThe EBRD has a specific mandate to promote transition to a market economy and to ensure environmental sustainability in all its operations. Additionally to the unacceptable environmental impacts of the hydropower plant projects Ombla (Croatia) and Boskov Most (Macedonia), both projects do not comply with the EBRD’s mission. We believe the bank should not support them.
Open letter requesting EBRD to withdraw from the Ombla hydroelectric plant project
Advocacy letter | 26 October, 2011 | Download PDFThe Ombla hydropower plant is planned to be built in a cave in Croatia that is part of a proposed Natura 2000 site, but the environmental, economic and social impacts have only insufficiently been assessed by the project promoters. More than 30 Croatian and international civil society organisations therefore urged the EBRD to not approve a loan for the project.