Reservoir Structures – Dams – Reservoir Commission

(Large) dams are defined as barrier structures that exceed a certain size/height (namely, a structural height of > 15 metre and/or impound a water volume of more than V > 500,000 cubic metre). Artificial reservoirs that store water "above ground level" as well as flood retention basins are also classified as dams. If barrier structures merely impound flowing watercourses (such as weirs or run-of-river hydropower plants), they are not considered dams.

On the Safety of Reservoir Structures

Austria’s reservoir structures make an important contribution to the generation of renewable energy from hydropower and to the storage of surplus energy from wind and photovoltaic installations (storage and pumped-storage power plants). In addition, they serve to provide flood protection (flood retention basins) and to supply water for technical snow production for winter tourism (snowmaking reservoirs). As disasters abroad have repeatedly demonstrated, the failure of a reservoir structure can have serious consequences for the public. Owing to their inherent hazard potential, reservoir structures must therefore meet very high requirements with regard to structural stability and operational safety.

The owners and operators of these, in most cases highly complex, engineering structures are obliged to carry out careful monitoring and maintenance as part of their own surveillance programme in order to ensure an appropriate level of safety.

In addition, the State carries out independent safety inspections as part of external supervision through particularly qualified bodies. On the one hand, use is made of the measuring and monitoring systems installed at the facilities. The operators are required to present the results in annual safety reports and submit them to the Water Authority of the respective federal province and to the Dam Safety Supervision Unit of Division I/4 – Water Management for Hydraulic Structures at the Federal Ministry of Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management. On the other hand, periodic, comprehensive on-site inspections are carried out by the Federal Minister within the framework of event-based water supervision, with the involvement of experts from the Austrian Reservoir Commission (the so-called “Subcommittee for Dam Safety Supervision”). The improvement and maintenance measures required during these inspections are intended to ensure that structural stability and operational safety are maintained over the long term and that the state of the art is complied with. The state of the art is defined, among other things, by guidelines and manuals prepared by the Reservoir Commission.

To ensure the long-term integrity of reservoir structures, not only a conservative design (incorporating safety margins) but also sensitive monitoring of the structure by trained personnel and representative measuring systems is required.

For the extremely unlikely event of damage to the structure or unexpected behaviour (such as extreme natural disasters or terrorism), additional emergency measures must be developed (emergency plan). Further details can be found in the "12 Thesen zur Sicherheit der großen Talsperren Österreichs" (12 theories on the safety of large dams in Austria).

Reservoir Commission

The Austrian Reservoir Commission (STBK) has been established at the Federal Ministry of Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management to provide expert assessments of reservoir structures and to assist the water authorities both within and outside water rights proceedings. The organisation and responsibilities of the Reservoir Commission are laid down in the Reservoir Commission Ordinance 1985.

The STBK consists of the Head of the Water Management Section (Chair: Section Head Monika Mörth), the Executive Secretary (Executive Secretary Mister Bernhard Weichlinger, Division I/4), and renowned experts in dam engineering and related disciplines. Membership of the STBK is an honorary appointment.

Legal bases for reservoirs

Essential public interest aspects of dam security assessment and monitoring are regulated by the Water Rights Act of 1959 (WRG1959) and the Ordinance on the Austrian Reservoir Commission 1985 (Staubeckenkommissionsverordnung 1985).

Requirements related to the internal monitoring of dams and reservoirs by the operator (dam officer), external monitoring by government agencies (national water authorities, Austrian Reservoir Commission – federal dam monitoring) and consultation of the Austrian Reservoir Commission are laid down in the following legally relevant provisions.

- Austrian Water Rights Act 1959

• Section 23a: regulates the requirements for dam officers
• Section 104 (3): specifies in which cases opinions must be requested from the Austrian Reservoir Commission
• Section 131 (1): regulates the periodical inspections to be carried out by the Austrian Reservoir Commission
• Section 134 (7): specifies, among other things, that the water authorities may, in the interest of public safety, prescribe the monitoring even of smaller dams by the Austrian Reservoir Commission and require the appointment of a dam officer.

In October 2023, the Federal Ministry of Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management published the Guideline for the Surveillance – Including On-site Inspections – of Reservoir Structures (in German only), as the significance and hazard potential of reservoir structures require the smooth cooperation of all parties responsible for their surveillance.

The guideline summarises the obligations of water rights holders and dam safety managers, the responsibilities of the dam safety supervisory authorities of the federal provinces in charge of water supervision, and the additional inspections carried out by the BMLUK with the involvement of the Austrian Reservoir Commission.

Dashboard for Large Reservoir Structures

Information on the characteristics of reservoir structures, data on electricity generation, and the historical development of Austria’s large reservoir structures can be viewed in aggregated form in the Large Reservoir Structures Dashboard.

Large Reservoir Structures Dashboard (in German only)