Lipno, Lipno Valley Reservoir, Lipno I or the Lipno Dam is a waterworks built on the Vltava River in 1952–1959. With an area of 48.7 km2, it is the largest dam reservoir and the largest body of water in the Czech Republic (thanks to which it is also sometimes referred to as the Czech or South Bohemian Sea). The length of the swell is 42 km. The widest is the reservoir at Černá v Pošumaví, where it spills up to 5 km. On the right bank, it extends to the state border with Austria.
The history of the Lipno Dam began during the great floods of 1890. In response, engineer Daniel published a brochure in which he first mentioned the establishment of smaller dams along the Vltava River to contain the floods that had plagued cities for many years. The idea is further discussed by the Assembly of the Kingdom of Bohemia, and in 1899 the Jan Jirsík Building Council proposed the construction of several dams. This project was also discussed, but farmers were not willing to sell their land.
Further floods in 1920 encouraged the construction, and in 1930 concrete projects were created for the construction of a new dam in Lipno. However, it was not possible to buy land for flooding and the war came. After the Second World War, the expulsion of the Germans and the nationalization of the Loučovice paper mills, there was a shift. The project of its current form was created, including a hydroelectric power plant.
Construction of the dam began in 1952 and lasted until 1958. It was unique in its scope and the use of new technologies. The landscape had to be adapted for flooding. From the beginning of the construction, various shafts were excavated, rocks were broken for sealing screens and the gravity block of the dam. 1670 hectares of forests and 86 hectares of other areas were cut down, including scattered greenery and various shrubs. 300,000 m2 of wood was obtained. Municipalities, settlements, roads and railways were also flooded (in detail in the section of defunct settlements and buildings).
Between 1953 and 1956, a 3.6 km long waste tunnel was dug. It transfers water from the hydroelectric power plant to the Lipno II buffer dam. In October 1956, Prague's Energovod began assembling a 100-kilovolt substation, and work began to move underground. In the middle of January 1957, the excavation of a rock in the underground was started and the assembly of a turbine generator was started on the Vyšší Brod "balancer". On June 26, 1958, the last block of the dam was concreted and leveled to road level. 14,000 m2 of concrete and 1,000 m2 of steel reinforcement were used, approximately 300 tonnes of machinery. On September 1 of the same year, the builders handed over the construction to the fitters of Elektrostroj Brno for the construction of the power plant. After half a month, these works were completed.
In February 1958, the dam was filled. It thus became the fourth stage of the Vltava Cascade in time series after Vraný, Štěchovice and Slapy. On June 15, 1959, the water spun the turbines of a hydroelectric power plant for the first time. The 350-ton rotor set in motion and began to generate electricity.
Zenáhlík and Behemský case
In 1953, the staff of the Communist Secret Police of the StB discovered that an illegal "imperialist" radio station was in operation in the construction area of the Lipno Dam. He was accused by MUDr. Josef Zenáhlík and the engineer of the dam construction Antonín Behemský from the "anti-state group Zenáhlík" who opposed the new communist regime in the country since 1948. During the interrogation, conducted by the then usual methods of the StB, MUDr. Zenáhlík admitted that he cooperated with French intelligence. In a trial in 1954, Zenáhlík was sentenced to 14 years in prison and Behemenský to 2 years for "endangering state secrets". In 1968, however, the court files were re-examined by the Regional Court and the 1954 judgment was annulled in full.
On August 17, 1975 in the area of the Lipno dam reservoir doš