MapStream: An inventory of barriers in Sarantaporos sub-basin, Aoos river basin, Greece

Create an inventory of barriers in Sarantaporos sub-basin, develop criteria for dam removal and build a solid case for the removal of five barriers


The Sarantaporos River is a main tributary of Aoos/Vjosa, a transboundary river shared between Greece and Albania, which has been characterised as the longest and the last free-flowing river in Europe. The Sarantaporos catchment, part of the wider Aoos river basin, is a riverine biodiversity hotspot, boasting extensive and unfragmented riparian forests and hosting important fish species (such as the European eel and the West Balkan trout), large carnivores (including the Eurasian otter, brown bear, grey wolf and Balkan chamois) and invertebrates. At the same time, the catchment area is one of the most remote areas of Greece and ranks among the poorest EU regions. 

At a glance

Project typeBarrier identification and prioritisation
Project statusLive
Project websiteMedINA

Project context and opportunity

It is estimated that the streams feeding the Sarantaporos River contain many small, in some cases obsolete, barriers, but very limited data exists regarding their actual number and state. At the same time, the area faces significant threats from planned Small Hydropower Plants (30 SHPs are under different licensing stages in the Sarantaporos sub-basin), which, if constructed, will cause irreversible fragmentation to this important transboundary ecological corridor. MapStream will provide comprehensive knowledge on the location, characteristics and status of barriers in the Sarantaporos sub-basin producing the first detailed inventory of the entire hydrographic network at the catchment level in Greece and pilot a methodology for pre-demolition case-building in a Greek context, both lacking and of great significance. The project will also launch a public dialogue about the negative impacts of obsolete barriers and advocate for their removal while raising awareness against the creation of SHPs in the area. 

Project aims

MapStream comes to fill an important gap in Greek water management policy and practice: the lack of comprehensive data on small barriers and the absence of an enabling framework for removing obsolete structures. To achieve its aims, MapStream will: 

  • create a comprehensive GIS inventory of river barriers in the Sarantaporos catchment, including short descriptions, technical details, and pictures, 
  • develop a methodology for selecting barriers for removal, using criteria such as the current operational status, local conditions, ownership status, and flood risk, and 
  • sensitise and mobilise stakeholders at all levels to take action for their removal. 

By the end of the project, conditions will be in place for removing five barriers, and project outputs will be shared with national, regional, and local authorities.