Foto: Vojta Herout, www.nafotime.cz
Lítožnice Landscape Park
The suburban landscape between Prague-Běchovice and Prague-Dubeč has become unrecognizable in recent years. To replace the previously straightened Říčanka riverbed, a naturally meandering shallow stream with waterlogged meadows and a number of ponds have been restored. Instead of three fish-breeding ponds in a state of disrepair, there is now one large Lítožnice pond with little islands, extensive litoral vegetation and pools, allowing for extensive fish farming. Walls for kingfishers, a sand dune, a wintering site, dead wood and dying trees in the pond floodplain form a refuge for many animal species. Thanks to these changes, the area manages water better in dry conditions as well as at times of high water inflows. It is also a nice place to go for walks and relax in nature.
The Adaptation Journey
The positive impact
Anti-drought measures and flood protection around the Lítožnice pond are combined with the support of biodiversity and the recreational potential of the suburban landscape. It is possible to retain water here through a water reservoir with an area of almost eleven hectares and fully revitalize the watercourse of the Říčanka river, which was previously straightened.
As Lukáš Řádek, the company's managing director, said: “the project is, among other things, the result of excellent synergies between the investor and the designers. During the demanding design process, there was a joint and positive improvement of ideas, which led to the ideal goal. The project thus perfectly fulfilled the potential of the area with many societal functions.”
How does it work?
First, the mud from the V Mejtě and Nový ponds was removed, as well as their dividing dikes and discharge facilities. In total, more than 48,000 m3 of material were exported from these two ponds. Islands for the future Lítožnice pond were created where there were valuable or mature trees on the dividing dikes. Some trees were left directly in the flood for spontaneous decomposition.
The Myslivecký pond was left intact the longest so that there was a body of water in the area to allow for the existing waterfowl and amphibians. Later, 20 m3 of material were removed from this pond. All material was used in the area for terrain modelling. New pools and sand dunes were created. The original historic dam was also restored, in several stages, and its missing part was completed in order to fill the entire large Lítožnice pond.
The whole floodplain of the stream served the revitalization of the Říčanka. The length of the new riverbed is three hundred meters longer than the original one. A system of larger and smaller pools, with a total area of almost six thousand square meters, was also created. The shore of one of the ponds was modified to create a vertical wall for kingfishers. The trees that had to be felled served as dead wood both for the stream and the pools. The original riverbed is now filled in; only one pool was left.
A wildflower meadows seed mixture was sown on the whole area of the floodplain. Now there are two fords made of boulders and two wooden bridges crossing the stream. The fords were formed in the watercourse only after the modifications had been completed and the flow of the stream had been normalized so that they are at the correct height.
The planting of an “orchard of the republic” is being prepared for some time in the future. The orchard will have the shape of the Czech Republic, and the trees will be placed here according to the locality in which they are most often grown.
The first mention of ponds in this location dates back to the 16th century. The appearance and number of ponds changed over time. Before the revitalization there were three ponds: Myslivecký made in 1953, Nový and V Mejtě made between 1969 and 1970. The Říčanka stream flowed between them and fed them. However, the ponds were in a state of despair due to neglected maintenance. The remnants of the water areas gradually disappeared, and the excess of sediments hindered the development of fauna and flora. The main dam, having served for several centuries, was in a surprisingly good condition. The side partitions built in the 60’s and 70’s were completely eroded and, in places, only a couple of feet wide.
In the vicinity of Lítožnice, the Říčanka stream lost its natural character long ago. The riverbed was already straight on maps from 1848. In the 1960’s, the whole stream was reinforced with wooden fences. In the past, this was considered a measure close to nature, but over the years, these measures are assessed differently.
Operation and maintenance
When it comes to the maintenance costs, it is important to include the maintenance and regular inspections of the Lítožnice pond, mowing of meadows, clearing and pruning of forests and the repairs of roads and equipment. The cost is now estimated at 300 thousand crowns a year.
There is now an agreement with a local farmer to mow the site twice a year for free and keep the hay.
Why was the measure chosen?
During the design process it was important to consider the high-voltage line, the planned construction of the city bypass and the relocation of road 511. Options were considered only for the pond – whether the stream would flow into it directly or whether there would be a smaller side stream feeding it. In the end, the first option was chosen so that the bypass ditch did not form a barrier around the pond.
Obstacles and challenges
Before the revitalization began, it was necessary to resolve property rights. The V Mejtě pond was originally managed by the Prague - Dubeč council, which also came up with the idea of the revitalization and approached the Capital City of Prague council. The Nový and Myslivecký ponds were owned by Xaverov, a company, which agreed to sell them - also due to the derelict condition of the ponds. After that, only a few smaller plots of land around the dikes remained to be sorted. These were owned by the Jeneč Farm, which was in liquidation at that time. These plots of land were eventually bought and the whole area was consolidated, and it was possible to start revitalizing it.
Nature protection was a big challenge and an obstacle at the same time. The location is a listed nature monument, and it was important to maintain continuous conditions for waterfowl and amphibians. It was, therefore, not possible to drain all three ponds at once; work had to be done in stages.
Archaeological research was another challenge. Extensive remains of a Germanic settlement from Roman times and the remains of the medieval abandoned village of Lítožnice were discovered during the extension of the pond floodplain and the extension of the dam. The extensive survey lasted until 2020. Visitors will be able to learn what archaeologists found here in the future thanks to an educational trail and a mobile app that will show them what the place looked like 2,000 years ago.
Operation and maintenance
Unexpected inconveniences were connected to the construction of a new concrete monk outlet structure. As it turned out later, the subcontractor did not have sufficient experience in the construction and when the pipeline was being covered with concrete; insufficiently anchored pipes floated up. The second attempt turned out better, but after the completion of the monk outlet structure and the dam, it turned out that the monk outlet structure and the outlet pipe were 45 centimetres higher than the projected placement. This created an inexhaustible area of approximately one and a half hectares. The monk outlet structure and the pipes were therefore demolished and rebuilt. In addition, during the demolition, it was found that the monk outlet structure was not connected to the foundations. It was only on the third attempt that it turned out as the project was designed.
It is still early yet to evaluate the operational experience; the site was opened only recently. However, the groundwater level is already rising, due to the floodplain getting wetter.
How much did it cost?
The cost of the project reached 54 million crowns.
The project was funded by the Capital City of Prague.
The investor does not quantify the return or savings for this type of investment. With appropriate maintenance, the service life is unlimited.
Revitalization of water elements Agriculture landscape Biodiversity Floods and torrential rainfall Lack of water and drought Landscape greenery