More than 180 anti-flood measures are to be built during a project to strengthen flood defences in Slovenia’s Gradaščica river basin. The first phase of the project will ensure protection for nearly 18 000 inhabitants and 3 000 buildings on an area of around 6 km². The first phase of this two-phase project is funded by the EU. Stage A of phase 1 will significantly improve flood safety in the south west of the capital, Ljubljana, while stage B of phase 1 will focus on the municipality of Dobrova-Polhov Gradec.
- 01 January 2007
“Once all arrangements and measures have been implemented within stage 1A of the project, flood protection of south-western Ljubljana will be improved to the extent that, even in the event of floods such as occurred in 2010 and 2014, populated urban areas will not be flooded.”
Work in Ljubljana includes regulation of the Gradaščica and the Mali Graben and Horjulka creeks, flood protection in the districts of Kozarje and Kosovo Polje and establishment of a landfill at Gameljne for surplus material from the work.
In Dobrova-Polhov Gradec, the Gradaščica in Dolenja Vas and Šujica and the Božna and Mala Voda creeks – the confluence of which forms the source of the Gradaščica – in Polhov Gradec are being regulated. Also, preparations are being made for the second phase, the main element of which is the building of the Razori dry dam.
Regular flooding
Due to its location in a valley which retains water and causes it to flow in torrents during intense rainfall, Dobrova-Polhov Gradec is vulnerable to flooding. The potential for damage is exacerbated by dense urbanisation in south-western Ljubljana and poor drainage from the Mali Graben, into which excess water from the Gradaščica basin flows.
Specific actions in Ljubljana involve the construction of flood walls and embankments, installation of drainage systems and widening of the bed of the Mali Graben. In addition, a 1.6 km relief channel is being dug south of the Ljubljana ring road. It will flow into the Curnovec stream which empties into the Ljubljana marsh.
Stronger embankments
In Polhov Gradec, stretches of the Božna and Mala Voda are being deepened, and maintenance is being performed on the bed of the Božna. In addition, an embankment is being built, flood walls are being raised, a spillway is being lowered, and walls next to the riverbed are being restored.
At Dolenja Vas, embankments are being raised and extended. Measures undertaken in Šujica include strengthening and raising of riverbanks, widening of the riverbed, elevation of a road and construction of a bridge over the Krnica stream.
Ancillary works entail demolition of buildings, landscaping and relocation of transport and public utility infrastructure. Measures to protect cultural heritage and the environment are included, with special attention paid to preservation of floodplains, water quality and habitats in conservation areas and creation of fish sanctuaries.
Total investment and EU funding
Total investment for the project “Flood control of the Gradaščica river basin” is EUR 49 466 450 with the EU’s Cohesion Fund contributing EUR 42 046 482 through the “Implementation of the EU Cohesion Policy” Operational Programme for the 2014-2020 programming period. The investment falls under the priority “Supporting climate change adaptation measures to reduce the risk of flooding in areas with significant flood risks”.