Ossiacher See, with around 10.8 km² and a maximum depth of 52.6 m, is Carinthia's third-largest lake. Passenger shipping with eight landing stages, lido facilities with bathing jetties, the gauge of the Hydrographic Service and around 36 km of pressure pipelines on the lake bed shape the underwater infrastructure. ScanSustain inspects the entire lake depth ROV-based — a multi-day deployment is typical. Actual deployments are subject to approval by the responsible local authorities, facility operators and shipping administrations.
These structure types can be inspected ROV-based at Ossiacher See — subject to approval from local authorities and operators:
Scheduled passenger shipping is operated by Nageler Schifffahrt. According to the operator, eight stations are served: Landskron, Annenheim, Sattendorf, Berghof, St. Urban, Bodensdorf, Ossiach and Steindorf (Steindorf not in the off-season). Berghof and Sattendorf were renewed in 2021 and 2023 respectively, and the Ossiach landing stage was refurbished in 2021. Inspection of berth edges.
At the four EU bathing sites Ossiach, Bodensdorf, Annenheim and Heiligengestade, bathing jetties provide access to the water; at the St. Andrä lido of the City of Villach both jetties were renewed. The Austrian Federal Forests (ÖBf), which own the lake, let lake-bed areas for jetties, buoys and boathouses. Findings capture of structural components.
Around 36 km of wastewater pressure pipelines of the Wasserverband Ossiacher See lie on the lake bed. They connect nine main pumping stations with the landfall shaft at the western end; the first pipelines went into operation in 1971, and a south-shore pipeline was added in 2015. The PE pipes are ballasted with weights and secured at bends via fixed points and cables.
Gauge “St. Andrä-See” of the Carinthian Hydrographic Service: staff gauge since 1896, pressure probe with remote data transmission since 1997.
Typical damage patterns at Ossiacher See:
Support piles: fungal attack, pile drift.
Seasonal growth layers.
In bays and the approach zones of landing stages. The main inflow, the Tiebel, carries suspended matter into the lake; settling basins were built at its mouth, and in 2009 sludge was suction-dredged from 11 ha of the lake bed.
Ossiacher See water is clear (visibility 2 to 4 m). ROV optics primary, sonar complementary.
For method selection in ROV deployments, the lake's depth profile is decisive: near-shore structures such as jetties, landing stages and lido facilities typically lie in the range of 1 to 10 m. The lake consists of two basins separated by a sill at around 10 m depth; the eastern basin is only around 11 m deep, and according to the Carinthian Institute for Lake Research the mean depth is 19.6 m.
52.6 m maximum depth. ROV systems cover the entire depth range.
Around 10.8 km² — Carinthia's third-largest lake.
The position of the thermocline varies with the season; area figures range from 10.6 to 10.8 km² depending on the source. For projects with accuracy requirements we recommend verifying these values in advance against a current hydrographic source — we do not take them as given unchecked when planning a deployment anyway.
For landing stages, gauge structures and jetty facilities at Ossiacher See, a geometric as-built survey can be useful alongside condition inspection — for example as a basis for rehabilitation planning or later monitoring. With Survey & Mapping, ScanSustain offers photogrammetric and multibeam-sonar-based capture that delivers depth profiles, site plans and 3D models in CAD/GIS-ready formats.
The lake is owned by the Austrian Federal Forests (ÖBf); they let lake-bed areas for jetties, buoys and boathouses, whose number and size are set by the competent provincial authorities. The water-rights authority is, in principle, the district administration — at Ossiacher See the Bezirkshauptmannschaften Feldkirchen (Ossiach, Steindorf am Ossiacher See) and Villach-Land (Treffen am Ossiacher See with Annenheim and Sattendorf) as well as the City of Villach. The shipping authority is the Office of the Carinthian Provincial Government (Department 7). The gauge is operated by the Carinthian Hydrographic Service.
Within 100 m of landing stages used by passenger shipping, bathing, swimming and recreational diving are prohibited; we coordinate work at landing stages with the shipping operator. In the European protected area “Tiebelmündung” (municipalities of Steindorf and Ossiach), navigation with vessels and floating bodies of any kind is prohibited; the district administration may grant exceptions in individual cases.
Around 10.8 km² surface area (Carinthian Institute for Lake Research), 52.6 m maximum depth.
Yes, in close coordination with the organisers. Outside it (May, October) it is logistically easier.
From the Burgkirchen base, about 3 hours' driving time. Multi-day deployments are typical.
Yes, as part of Survey & Mapping — currently as a pilot service, with photogrammetric and multibeam-sonar-based capture for depth profiles, site plans and 3D models in CAD/GIS-ready formats.
As a rule, yes. Under water law, the responsible bodies are, depending on the shore section, the Bezirkshauptmannschaften Feldkirchen and Villach-Land or the City of Villach; the shipping authority is the Office of the Carinthian Provincial Government. The affected municipalities of Ossiach, Steindorf am Ossiacher See, Treffen am Ossiacher See and Villach and, where applicable, facility operators are also involved. Additional restrictions apply in the European protected area Tiebelmündung. We clarify responsibility in advance together with the client.
Ossiacher See is considered a clear body of water with visibility of 2 to 4 m. This allows a primarily optical ROV inspection; sonar is used complementarily.
Describe your use case — within 1 to 3 working days you will receive a concrete initial assessment with method selection and an effort indication.
