Upstream, construction crews were working on a hydro-power dam and plant that the regional Serb Republic government commissioned as part of a move away from fossil fuels, but that activists worry will affect the river's flow and ecosystem.
"Economically, the people live of rafting, but there is a threat that Neretva will be completely changed," Kusturica, from the Atelier for Community Transformation campaign group, said.
Shifts in the water level caused by the dam would disrupt wildlife and rafters - tourists and competitors in this month's European Rafting Championship alike - she added.
"Vegetation and the animal world - Adriatic brown trout, sculpin, marble trout - all of them are endangered."
Power trader and operator Energy Financing Team (EFT) first got the 120 million Bosnian marka ($65.8 million) concession to set up the 35 Megawatt plant in 2009, with China's Sinohydro [RIC:RIC:SINOH.UL] chosen to construct it.
EFT told Reuters it had taken steps to protect the environment throughout the project, which was due to be operational by the end of the year.
"All necessary preventive measures to stop negative impact have been applied at the Ulog dam construction site," it said in a statement.
"During the preparation phase for the realisation of the project, extensive research works have been conducted and all specifics of the terrain taken into account when project solutions were defined and works conducted."
The regional government's ministry for construction and ecology said the site of the plant has already been shifted once in response to geological risks in the area prone to landslides.
It added there had been no complaints made in response to environmental protection plans issued when the plant first got the go-ahead.
The region's energy ministry, which cleared the project, did not immediately respond to requests for comment.
The statements have not reassured the activists, and many people in the southern riverside town of Konjic who have built their lives and livelihoods around tourism.
Pippa Gallop of CEE Bankwatch, a network of environmental and human rights groups in central and eastern Europe, said the dam would block the upper Neretva "flooding almost five kilometres of this otherwise pristine ecosystem".
"With tourism we preserve the nature and can live well off it," Teufik Niksic, who organises rafting tours in Konjic, said.
Packing the river with rafters and holiday-makers would "earn more millions than those who want to block it and destroy its purity, colour and the life of endemic species."
Bosnia - which gets 40% of its electricity from hydro power and the rest from coal-fired plants - is one of the few nations in the region with enough capacity to export power.
(Reuters, June 26, 2024)