Slovenia is a country of high mountains and fast-flowing rivers - ideal for generating hydroelectricity. But environmentalists are protesting planned dams and questioning whether laws are being broken.
On a plunging mountain stream that flows into the Sava River, Rok Rozman - kayaker, adventurer, biologist and former Olympic rower - is out doing what he loves most: kayaking the wild rapids with his mates.
"You really enjoy being a part of it, and if there are tough rapids, you concentrate on the rapids," Rozman says. But Rozman is also a biologist. "I constantly look around for birds and fish - maybe that's why I sometimes hit rocks," says Rozman jovially before thrusting his kayak over what seems like an impossibly steep waterfall.
Mokrice dam one in chain of five
The waters of the Sava River at Mokrice close to Slovenia's border with Croatia are quieter than those where the kayaker gets his thrills.
And that's where a hydropower dam is planned, the last in a series of five being constructed on a stretch known as the lower Sava. Together, they should produce about 5 percent of Slovenia's electricity.
Just upstream from Mokrice at Brezice, where construction is nearing completion on another of the dams, Rozman and other Slovene environmentalists are determined to stop the dam - which they say threatens fish species.
The dam projects are being touted not only for their capacity to produce electricity, but also for their ability to reduce flooding.
"The public is most concerned for groundwater and flood safety,” says Andreja Slamersek, president of the Slovenian Native Fish Society. She says companies investing in and building the new hydropower stations are also putting money into convincing large segments of the public that the dams will help with flood mitigation.
Slamersek describes the dam building program as "a catastrophe" for the rivers.
Clean energy in conflict with conservation
Ulrich Eichelmann, the founder of Riverwatch - an international non-governmental organization campaigning for the protection of river habitats - fears impacts from the dams upon species that are already endangered.
"Fish need the cold-water, fast-flowing, gravel type of habitat," Eichelmann says. He says the dame will destroy "a very important spawning site for an endangered fish species called the Danube Roach."
Eichelmann does not share the dam construction company's view that it can protect the spawning grounds of endangered species. He says if the dam is built the fish "will be gone" because mitigation measures proposed by HESS cannot suitably replicate the fishes' natural environment.
Fish like the Danube Roach need cold, fast-flowing water to spawn - something dams typically take away
Good arguments for hydropower
DW was able to speak with Erwin Mayer, general secretary of the Austrian Small Hydropower Association, a lobbying group for Austria's many smaller hydropower producers.
Mayer says that as long as European and national laws like the Water Framework Directive are fulfilled, then new dams and hydropower plants will be able to be built.
This regulatory framework involves maintaining the stream's "good" status, and insuring the existing ecological status of the river is not downgraded. Provided this is done, Mayer says dams like Mokrice should go ahead.
Fish migration is the crucial thing, he says. "If you have these fish passes, then you should use renewable energy sources."
The plans for the Mokrice dam, published by HESS, include such fish passes.
Mayer also supports such dams because the power they produce is "decentralized, non-nuclear and CO2-free." He points out that this can be an important part of the transition to an climate-friendly electricity production system.
Questions over assessment
But according to Eichelmann, Slovenia's implementation of the legislation is flawed.
As member of the European Union, Slovenia must uphold EU legislation, including on water and the environment.
An environmental impact assessment, issued as required under Slovene law, initially recommended against the Mokrice dam, saying environmental protection could not be guaranteed.
But when HESS commissioned a second assessment from a different consultant, this gave the dam a clean bill of environmental health.
"Within a few weeks, without changing the project, the project got the green light saying everything can be mitigated," says Eichelmann, a veteran anti-dam campaigner.
The company constructing the Mokrice dam is known as HESS, a subsidiary of the HSE group (Holding Slovenske Elektra).
A number of calls to HSE seeking an interview with its CEO were not returned, and emails to the media department asking for answers to questions - including why two environmental impact assessments came to different conclusions on the dam - went unanswered.
On its homepage, HESS says of the Mokrice dam: "Measures will be taken to assure an optimal use of electricity while the current natural state will not be affected in any way."
Kayakers and tourists appreciate Slovenia's wild, free-flowing rivers, like here in the Sava River headwaters
Impact on tourism
People opposing the Mokrice dam, along with the many others in the planning pipeline for Slovenia, also point to potential negative economic effects.
According to Slovene government figures, tourism accounts for about 13 percent of gross domestic product - making it one of the country's most important industries.
If built, the Mokrice dam will supply less than 1 percent of Slovenia's annual electricity needs, according to figures published by HESS.
Kayaker and biologist Rozman thinks the country will be losing far more than it gains. He cites the wild rivers and fish biodiversity as attracting tourists from all over the world to his tiny mountainous country.
"The big question is why do all these people come to Slovenia - and the answer is because we have all these beautiful rivers, and the rivers don't have dams," says Rokman.