Hydropower Scheme Threatens to Irrevocably Alter Iconic Neretva in Bosnia, Croatia

During a lifetime spent on the Neretva, Miroslav Dugandzic has watched its waters change.

“Fishing has been in my family for four generations,” he said, sitting in his living room in Komin, a village in Croatia near where the Neretva empties into the Adriatic after wending its way through southern Bosnia and Herzegovina.

Now in his eighties, Dugandzic learned his trade from his father and taught it to his son, Ante, who now runs the family business alongside him.

He fears, however, that his grandson will never get the chance: the tools and techniques Dugandzic inherited were made for a river that no longer exists.

“Some species are gone, they are extinct from this area, because the fish habitat changed a lot,” he said.

Home to one of Europe’s largest wintering grounds for birds, as well as fish and cave species found nowhere else on earth, the Neretva is not what it once was, its flow diminished by dams and tunnels built over the past 60 years. And as less freshwater reaches the delta around Komin, the further the seawater encroaches upstream, turning the river salty, changing its ecosystem and sterilising the soil.

Environmentalists say the river’s plight is about to get worse.

Contractors in Bosnia are putting the final touches to the Dabar hydropower plant, the first of three envisaged in the Neretva river basin under a project known as Upper Horizons.

Located in Bosnia’s predominantly Serb-populated Republika Srpska entity, the project’s impact will be felt over the ethnic boundary line in the mainly Bosniak and Croat Federation entity and in Croatia, where the river meets the sea. This makes mitigation efforts highly complex and politically fraught.

In 2021, a Croatian MP cited estimates that Upper Horizons would siphon off two billion cubic metres of water from the Neretva every year, roughly equivalent to 800,000 Olympic swimming pools.

“What we can foresee is less water ending up in the Neretva via its tributaries Buna, Bunica and Bregava,” said Pippa Gallop, Southeast Europe energy advisor at the environmental watchdog Bankwatch.

The sheer scale of the project means impact assessments are hard to make. Pressing ahead, said Gallop, means “gambling with something that is not really understood”.

Wetlands running dry

Farmland in the Neretva Delta, near the town of Opuzen. The delta is a major agricultural area, and would feel the impact of a further reduction of freshwater flow in the Neretva. Photo: Nick St.Oegger

Dugandzic took a piece of paper and drew a tool that looked like a cross between a trident and a rake, once used to catch eels.

“When people went to work in the fields they didn’t even need to bring food from home,” he recalled. “They would throw this in the river and catch four or five eels to put on the fire for lunch. Now all you get is plastic bags.”

Like the eel, many species have retreated or vanished.

Historical records are partial, but they point in the same direction.

For the past decade, reported commercial eel catches in Croatia, mostly from the Neretva estuary, haven’t topped one tonne a year, compared with around 45 tonnes in the 1970s. A 2021 paper also recorded the presence of eight marine species in the upper portion of the delta of the Neretva, more than 25 km from the river’s mouth.

On paper, the delta is well protected. It has been a Ramsar site since 1992, is part of the European Union’s Natura 2000 network, and hosts several national ornithological reserves. But none of that has stopped the hydropower construction across the border.

Upstream, in Bosnia, the river runs past Hutovo Blato, a nature park of lakes, swamps, wet meadows and riverine forests fed by dozens of springs. A Ramsar site since 2001, it covers more than 7,800 hectares and is one of Europe’s largest wintering grounds for birds migrating along the Adriatic flyway.

“For the people around and for the whole ecosystem it is very important because it is a reservoir of water,” said Irene Rozic, the park’s director. “When the Neretva is high, Hutovo Blato takes in all that water, avoiding floods downstream, and it does it in a completely natural way.”

Hutovo Blato, however, has already paid a price for the region’s hydropower.

“The damage has already been done, because of Lower Horizons,” said Rozic. “That’s when Hutovo Blato lost about 50 per cent of its water.”

Upper Horizons will only make things worse, with consequences felt well beyond the park’s borders.

The water that keeps Hutovo Blato alive comes from the mountains of eastern Herzegovina, where rain and snow collect during winter and drain through sinkholes in summer. The Zalomka river, for example, disappears into the ground in Nevesinjsko Polje and resurfaces kilometres away in the springs of the Bunica and Bregava, both tributaries of the Neretva.

Upper Horizons is designed to intercept this water before it goes underground.

Species found nowhere else on Earth

An inlet tunnel for the Upper Horizons project, in the Nevesinjsko karst polje. A reservoir would be created, flooding agricultural land in the surrounding areas. Photo: Nick St.Oegger

In May 2025, ichthyologist Matej Vucic made a discovery every biologist dreams about.

During fieldwork in Dabarsko Polje, he spotted a handful of juvenile Telestes dabar in a small pond, a fish nobody had seen for more than eight years. Some scientists had feared it was extinct.

“It was my first time seeing that species, and it was great to see it’s still out there,” Vucic told BIRN during a follow-up trip in the same area a year later.

As its name hints, Telestes dabar is an endemic species to the Dabarsko Polje, which means it’s only found there and nowhere else. On the same trip, Vucic found two other threatened endemic fish, Telestes metohiensis and Delminichthys ghetaldii.

The Bosnian karst poljes are the world’s main hotspot for cave species: no other place has such a rich underground life.

The reason is in its unique morphology. Poljes form in limestone, which water slowly dissolves into caves, sinkholes and hidden channels. It’s a morphology so typical of the Balkans that English borrowed the word from the original slavic to describe them.

“What we know is that all three species mostly live underground, but they need to come above ground for mating,” Vucic said. “If there is no natural cycle of flooding they wouldn’t be able to do that.”

Karstologist Ivo Lucic said the real extent of the damage cannot be known. “The caves that we can explore are just windows to the underground,” he told BIRN. “We can’t see the whole picture.”

Lucic explained that the environmental impact assessment is not up to standards. The karsologists say it relies on old data, not taking into account the decline in precipitation of the last decade. After Lucic pointed out the problem, BIRN consulted the document and noticed that it contains no mention of the Telestes dabar and several other endangered species.

“Karst is considered a poor area, people think that if we destroy it we don’t lose anything,” Lucic said. “They don’t understand that what lives underground is totally unique.”

Dabarsko, Fatnicko and Nevesinjsko Polje are candidate sites for the Emerald Network, the Council of Europe’s equivalent of Natura 2000 for non-EU countries. In 2022, the Bern Convention asked Bosnia to ban new hydropower plants in the Neretva basin’s candidate sites, including these three fields. At the national level, however, none of them is protected.

Nevesinkso polje is where the Nevesinje reservoir will be built to feed the Dabar plant. It is set to hold 61.8 million cubic metres of water and flood about nine square kilometres.

On May 25, 2026, the owners of plots located in that area were called to a meeting with representatives of the Office of the Attorney General of Republika Srpska and local authorities. According to Miljan Kovac, a journalist from the area and owner of one of the plots who attended the meeting, between 50 and 60 attended. They were offered about 3.5 euros per square metre.

“That is as much as was offered for the same plots 15 years ago,” Kovac told BIRN. “In the meantime, the price of everything has gone up.”

Much of the land is no longer farmed, Kovac admitted, but it is still used for grazing, and families have lived there for generations. The offer was refused.

Politics, bureaucracy

The Old Bridge of Mostar, a 16th Century Ottoman bridge spanning the Neretva River, in Mostar, Bosnia and Herzegovina. Photo: Nick St.Oegger

The bridge in Mostar, connecting the two halves of the city across the Neretva, is one of the most symbolic structures in Bosnia. Diving the 24 metres from it into the river has for centuries been a rite of passage for young men. Today, the tradition is kept alive by the Mostar Diving club.

On March 22, 2026, World Water Day, one of the club’s divers climbed over the bridge’s handrail and told the crowd: “I dedicate this jump to the Neretva, let our Neretva flow.”

The stunt was organised by Mostar-born Aida Kapetanovic of Foundation Atelier for Community Transformation, ACT, a Sarajevo-based environmental organisation, to raise awareness about the threat from Upper Horizon.

“The Neretva is a symbol of the city, together with its bridge,” Kapetanovic told BIRN. “If they destroy our Neretva, this tradition will die with the river.”

ACT has spent years trying to stop the project or at least mitigate its worst effects. “Our fear is that the springs of the Buna, Bunica and Bregava could completely dry up, especially in periods of drought,” Kapetanovic said.

While the plants are being built in Republika Srpska, Kapetanovic said that “a good part of the negative effects also falls on the territory of the Federation and all the way to Croatia”.

Working with the federal ministries for Environment and Tourism, and Agriculture, Water Management and Forestry, ACT helped draft an initiative that the Federation government adopted in June, requiring ministries to obtain all documentation and permits for Upper Horizons from Republika Srpska and to draw up measures to minimise the damage.

The Federation then asked the state-level government to create an inter-entity commission and to adopt a decision on improving cooperation on water resources. The motion failed to pass.

According to Bankwatch, Republika Srpska keeps renewing Dabar’s permits on the basis of a 2012 impact study, without public consultation, and has refused to disclose either the loan contract or the construction contract with the Chinese firm Gezhouba.

Complaints are pending under the Bern Convention and, since February 2026, under the Espoo convention on transboundary impacts, filed by Croatia.

For Kapetanovic, the institutional response is promising, albeit late.

Many people living along the areas that will be affected have not yet grasped what is at stake, she said.

“Until you see and live the impacts directly, it is hard to imagine that the water of a river could completely dry up.”

That’s not a reason to stop, Kapetanovic told BIRN.

“We have to at least minimise the impact this project can have on the environment and on the communities living on the Neretva.”

This article was produced with support from Internews’ Earth Journalism Network.