Croatia Launches Espoo Convention Procedure Over Gornji Horizonti Hydropower Project in Bosnia and Herzegovina

The Ministry of Environmental Protection and Green Transition has formally initiated proceedings under the Espoo Convention concerning the Gornji Horizonti hydropower subsystem in Republika Srpska, Bosnia and Herzegovina. The large-scale energy project предусматриes the construction of three hydropower plants.

Environment Minister Marija Vučković confirmed that the official procedure was launched in November through the Secretariat of the Espoo Convention, formally known as the UNECE Convention on Environmental Impact Assessment in a Transboundary Context. Both Croatia and Bosnia and Herzegovina are signatories to the convention.

According to Vučković, the ministry issued a written opinion arguing that the project’s development has not complied with provisions related to the participation of potentially affected states in projects with possible cross-border environmental impacts. While Croatia does not have the authority to block such infrastructure investments, it is entitled to be adequately consulted and to receive comprehensive responses to its inquiries.

Longstanding Environmental Concerns

Vučković emphasized that energy infrastructure development in the Trebišnjica river basin has, for decades, produced visible adverse effects in the Neretva river valley. She noted that numerous expert questions raised by Croatian authorities over the past 15 years — ranging from the HPP Dabar project to subsequent initiatives — remain unresolved.

“In the spirit of good-neighborly relations, Croatia will continue to insist on clear and substantiated answers,” the minister stated.

The Prefect of Dubrovnik-Neretva County, Blaž Pezo, warned that the Gornji Horizonti project poses a risk to the natural freshwater flow of the Neretva River. He underscored that Croatia is actively pursuing all available mechanisms to challenge aspects of the project that could negatively affect its territory.

Ministry of Environmental Protection and Green Transition

Parallel Investment to Combat Salinity in Lower Neretva

The issue was discussed in Opuzen during a visit by Vučković and Pezo to the site of a EUR 85.5 million environmental protection project in the Donja Neretva region. The initiative aims to safeguard land and water resources from salinization in the lower Neretva area.

The first phase foresees the construction of a barrier on the Neretva River to prevent seawater intrusion, with works valued at approximately EUR 30 million and an implementation timeline of four years. The second phase includes the development of a freshwater reservoir upstream of the barrier, intended to flush salt from agricultural soils and secure reliable irrigation supplies.

Structure of the Gornji Horizonti Subsystem

The Gornji Horizonti hydropower subsystem involves diverting water from the Gatačko (Gacko) and Nevesinjsko (Nevesinje) plains through the Dabarsko (Dabar) and Fatničko (Fatnica) plains into Bilećko (Bileća) Lake.

The project encompasses three hydropower plants — Dabar, Bileća and Nevesinje — and is being developed by Elektroprivreda Republike Srpske. Construction of the Dabar hydropower plant is currently underway.