AKTOR delivers €10.3M flood protection project in Thriasio Plain

The project, titled “Regulation of the Agios Georgios (Giannoulas) Stream – Eastern Thriasio Plain Attica,” has a total budget of €10.3 million and has been handed over to the Ministry of Infrastructure and Transport.

The project covers the section of the stream between Chainage 1+835.60 and Chainage 9+335.00, in the area of the Mornos siphon. Its main objective is to improve the watercourse’s flow capacity, stabilise and define the streambed, and protect infrastructure located along its route.

The Agios Georgios stream, which extends for 7.5 kilometres, is the second-largest stream in the Thriasio Plain after the Sarantapotamos. Its drainage basin covers approximately 110 square kilometres, including the Mavri Ora and Refinery streams.

The stream originates on Mount Parnitha and, after entering its lowland channel in the area of the Mornos aqueduct siphon, runs east of Aspropyrgos. It is then diverted parallel to the railway line and, in the Refinery area, follows an alignment alongside the facilities before crossing the New Athens–Corinth National Road and reaching the sea.

The Interventions

Extensive technical interventions were carried out as part of the project, tailored to the area’s hydraulic, geotechnical and morphological conditions.

Among other works, the streambed was reinforced with gabion structures, while 15-metre-wide rectangular reinforced-concrete sections were constructed, along with four new bridges, designated G2, G3, G5 and G6.

The project also included the construction of a bypass around Bridge G6 using 12 culverts, as well as a flow-splitting structure designed to safely convey the design flood discharge.

The works additionally involved cleaning and reshaping the streambed, sediment retention measures, road construction works and the creation of eight access zones to facilitate maintenance of the watercourse.

At selected locations, bored pile walls and retaining structures were constructed to protect adjacent structures and ensure slope stability. Landscaping interventions were also carried out to restore vegetation and integrate the project into the surrounding environment.

Protecting Critical Infrastructure

Particular emphasis was placed on sections where the stream intersects with road and rail networks, bridges and utility networks, given that the Thriasio Plain is one of Attica’s most important areas for industrial, logistics and residential development.

Strengthening flood protection is particularly important in an area where residential properties, agricultural and grassland areas, industrial facilities, and critical transport and energy infrastructure coexist.

For the AKTOR Group, completion of the project forms part of its broader infrastructure portfolio, with an emphasis on projects that enhance infrastructure resilience and protect communities and assets from the impacts of increasingly severe weather events.