Adjustment of the Blanice riverbed became water management construction of the year

On Friday 20 March 2015, a representative of the company HOCHTIEF CZ accepted from the Minister of Agriculture Ing. Marian Jurečka and the Minister of Environment Mgr. Richard Brabec Water Management Construction Award 2014. The project officially called “Enhancing the capacity of Blanice riverbed by nature-friendly methods in urban area of the town of Vlašim” won the prestigious award in the category “Constructions with investment cost over CZK 50 million”. The competition is annually announced by the Water Management Association of the Czech Republic and announcement of the winners takes place on the occasion of the World Water Day.

The winning project introduced in the Czech Republic a unique urban area remediation, which after more than fifty years has significantly changed look of Blanice´s riverbed and its surroundings. Constructors from the company HOCHTIEF CZ implemented a total of 24 buildings. The main part of the work included change of riverbed´s structuring by excavation of excess soil from the banks. Increase of capacity of the river was achieved by excavation, which in combination with the newly built flood control measures has significantly increased protection of surroundings of the river against floods. Protection of part of the territory and buildings against one-hundred-year flood is now ensured by stone flood protection walls with a thirty-centimetre freeboard. Flood resistance has been already verified during implementation of the project when in summer 2013 extremely strong flood went through the construction. It turned out that the already implemented modifications at the Blanice River were able to mitigate effects of the flood and damages to the project were not serious. Further work was carried out on adjustment and construction of weirs that were equipped with fish passes that enable migration of fish and other animals. By creation of riverbank holes and floodplain areas for flooding spills planted with bank vegetation a natural appearance of the river and its immediate surroundings was further supported.  

An interesting part of the delivery of the company HOCHTIEF CZ was installation of a new footbridge directly in the centre of Vlašim. The original footbridge formed a connection between Palackého square and Žižkovo square in the town centre and was the main access road to the House of Children and Youth. Due to its elevation above the water level the footbridge had been several times a year flooded until it was pulled down by the flood.

The new footbridge is located approximately in place of the original footbridge. The main bearing elements of the footbridge are two arches that simultaneously create railing of the footbridge. The footbridge is anchored in the anchor holes on both sides of the Blanice River. Its location is adapted to the reconstructed bridgehead at Stará radnice and gets over Blanice´s riverbed slightly askew. The lower edge of the structure is designed 0.5 m above the 100-year water level, for which all flood control measures that are part of this project are designed.  

The total cost of the project amounted to CZK 83.2 million, of which CZK 67.4 million were paid from subsidies from the Operational Programme Environment and from the state budget.