History

Vranov lake is the jewel of the Podyjí protected landscape area

The Vranov dam was built because the river Dyje often caused floods in the past and destroyed everything in its path. The only solution to this situation was the construction of a dam, whose concrete walls would hold backhundreds of millions of cubic meters of water, using the water to produce electricity in a hydroelectric dam.

The first concept of Vranov dam came before the First World War. During the holidays in 1903 the son of a builder from Vranov called Schmidt, who was an architecture student at technical college in Switzerland, presented, together with his fellow students, a project for the construction of a dam near Vranov nad Dyjí.

The project to use water power by building a dam was discussed by the company Podyjské závody (Thayawerke) in 1912. At the time, there was not yet money in Austria-Hungary for such a large project in Moravia. After the formation of the Czechoslovak Republic in 1918, in agreement with Podyjské závody the state and the Moravian Silesian country became the investor in the dam with the contribution of joint-stock company West Moravian Power Station.

In 1929 three joint-stock companies were authorized to construct the Vranov Dam: Českomoravská construction company in Prague, Lanna in Prague and Pittel und Brausewetter in Brno. The project, which was completed with the new knowledge gained in the construction of large dams abroad during the construction of a dam, was developed by the Provincial Office in Brno.

In March 1930 construction of a dam (on the river Dyje) in Vranov nad Dyjí (the largest water structure in the former Czechoslovakia), began together with the New Bítov, two bridges and engineering structures in the New Bítov under the direction of the chief land building adviser Ing. Karel Navratil. The work, where 2 500 people worked during the construction, was completed in three years and six months and the reservoir began to fill with water in the autumn of 1933. It began to operate in 1934.

The volume of water in the dam is about 150 million m3. The reservoir also receives water from the Želetavka, which flows into the Dyje near Bítov castle. Dam reservoir extends as far as 1.5 km below the Podhradí nad Dyjí. The total length of the lake is 30km, maximum depth (46 m) is directly against the wall and under the first bridge at Bítov reaches about 30 meters. The surface of the lake has an area of 763 ha and is situated at a height of 351 m above sea level.

Brilliant construction – the wall of the Vranov Dam was built as a gravitation wall in cast concrete. The width at the base of the dam is 27 m, the crest narrows to 6m. The length of the crest is 290 m, the height above the base is 54 m. The radius of curvature of the wall is 500m. The wall was divided into three parts by two reinforced blocks of 27 m. High water overflows the bridged left and middle part via the crest spillway.
On the left bank the cascades were set up to bring overflowing water from the crest in the left wing to the stilling pool below the dam.
Crest spillways are 122 meters long and have a capacity of 580 m3/sec. In the left side there are four blow-off pipes with a diameter of 1600 mm, which can emit water at the speed of 170 m3/sec. In the right side of the dam three pipes with a diameter of 2600 mm are located, bringing water to the plant built at the wall footing. Three Francois turbines are located in the power station, each of 5.44 MW with capacity of 15 m3/sec. For control, vertical shafts and three passage tunnels were built in the dam.

In 2002, the Dyje basin was hit by a flood, of an almost unprecedented nature and described as a 500 year flood. Among other things, the passage of the floods caused damage to the surfaces of concrete structures of the dam in the downstream face and weir crest, stone veneer and side retaining walls of the spillway cascade. The retaining walls of the spilling pool and waste outlet of the power plant were damaged. Both the building and technical parts of the engine room of the bottom outlet were also damaged.

This damage, together with the decision of a state enterprise to ensure maximum protection of people and their property provided the impetus to start repairs immediately to keep this edifice in good condition and to ensure its safe operation. Repairs, consisting primarily of the refurbishment of concrete structures started in September 2003. The first phase of repairs, costing 7.6 million Czech crowns, was completed in August 2004. The second phase of repairs entails work on a much larger engineering intensity and financial scale. This phase of work costing approx. 44 million Czech crowns, should be completed by the end of 2005 according to the contract with the contractor. The final phase of repairs to which the project documentation is being currently completed, and completion of all construction works is scheduled for autumn 2006.

Boat trips - History

The oldest operator of boat trips was the Nautical Club. Ladislav Prchal and his ship "Lada" operated the trips from 1935. In 1947 the entrepreneurs united themselves to create The Podyjské Spa and Shipping Group. They had a fleet of 8 ships, of which the most beautiful ship was the paddle steamer "Mír" which was solemnly “baptised“ on 14^th August 1949.

The boat "Morava" was one of the steamers too, imported from Vienna under the name Starnberg during the war in 1939. She was launched on the water of the dam on 11th August 1946 and was one of the fastest and most beautiful Vranov boats. She was scrapped in 1965. The boat named "J. Máša", later renamed "Brno", was scrapped too. Another vessel was the fast steamer "Praha", passenger vessels "Hvězda", "Znojmo", Hungarian hydrobuses "Dunaj", "Dyje", "Vranov" and "Košice".

The longest-serving boat was "Moskva" which, after the launching ceremony on the 20th June in 1981 served to 1992. Today, renamed "Moravia", you can see her in the dock Na Františku in Prague, where she is the most successful boat of Prague's Vltava fleet.

Boat trips - Present

Boat trips came into operation again in June 2006. In the off-season months only pre-booked sightseeing cruises are held, during the high season months there are regular boat trips. More at www.lodnidopravavranov.cz.

Vranov Dam today

The Pedestrian Bridge (Swiss Bay Bridge) is also a dominant architectural feature of the Vranov beach, built in 1992-1993, linking the beach with the dam.

Today, Vranov Dam is not only an important reservoir of drinking water, but it is used as a centre of recreation and tourism. The lake is surrounded by woods, beaches and cottages. It abounds with extraordinary natural scenery, especially deeply incised meanders, rock walls, bizarre rock formations. The hilly landscape is covered by autochthonous broad-leaved stands, especially oak, oak-hornbeam, beech, conifers - pines, spruce and larch. This area is characterized by an extraordinary diversity of plant and animal species. Climatic conditions are very favourable in the summer, when the air temperature exceeds 30°C and the water temperature ranges from 20 to 25 ° C. The water in the lake is clean for the whole season, without cyanobacteria. The picturesque nature of Vranov dam – The Moravian Adriatic, (as this area is called), attracts thousands of visitors for recreation from home and abroad.