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Maribor, Slovenia

Size or capacity

Installed discharge: 550 m3/s, power output: 60 MW, nominal power of generators: 3 x 26 MVA

Investor / Client


Time period


Description of Facility and Services

The Mariborski otok HPP is the last HPP located in the Drava River section extending from Dravograd to Maribor. It is exploiting the Drava River natural head of 14.20 m from the approximately 15.5 km upstream located Fala power plant. It is a run-off-river power plant of buttress type. Even though the Mariborski otok HPP does not represent a direct reference of IBE, its construction is inseparably connected with the Company foundation.

The Mariborski otok HPP construction began in far 1942, during the Second World War. After the War, only 30% of construction works were concluded while the design documents were destroyed or lost. It was a heavy and demanding task that the constructors had to face – to build a big hydro power structure that has never been built before in the late Yugoslavia, especially not with their own potential. New design documents for a new type of hydro power plant that was barely or hardly at all examined in the expert technical literature, had to be developed.

The Drava River with its up to 1600 m3/s discharge represented a great problem. In 1946, the construction was jeopardized two times while on July 9, 1946, one third of the Mariborski otok was washed away. In the years between 1947 and 1950, Mariborski otok was protected by a wave wall which has been preserved till nowadays, protecting successfully the remaining part of the island. The constructors faced big problems also during installation of the 3rd and of the 4th gate, taking place in 1948. Their enormous efforts were repaid with the first 24 MW aggregate start of operation on September 5, 1948. The Mariborski otok Hydro Power Plant was the first HPP of such capacity constructed after the Second World War. From all the hydro power plants on the then Yugoslavia territory only one scheme was bigger, i.e. the Tito HPP (62 MW) by Split. On September 19, 1953 the second aggregate was put in operation and in 1960, the start-up of the third one took place.

The Mariborski otok HPP construction was not important only from the point of view of electricity supply but above all from the point of view of experiences gained more than ever by our working collectives qualifying themselves for further hydro power plants construction projects implementation. During the Mariborski otok HPP construction, design engineers qualified for design of the biggest hydro power plants, especially for design of the other HPPs on the Drava River. From the former design engineering group working on the Mariborski otok Hydro Power Plant, in 1949 a new design engineering company of Hidroelektroprojekt, later on renamed to Elektroprojekt was founded. It paved the way to the ex- Inženirski biro Elektroprojekt and finally to the nowadays IBE.

IBE d.d., Hajdrihova ulica 4, SI-1001 Ljubljana, Slovenia
Telephone: +386 1 4776 100
Fax: +386 1 2510 527

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