Foto: Vojta Herout, www.vojtaherout.com
Rakováček Park in Rokycany
Czech winner of the Urban areas 2020 category
The flow of the Rakovský brook (Crayfish brook), named after an extraordinarily large population of protected stone crayfish, is no longer restricted by the artificially straightened riverbed. Now the stream lives its own life and zigzags through the newly created park. There are wooden trays and a rope bridge over the stream so that you can move freely from the left side of the shore to the right. There are also through-flow little pools on the creek. The lowered parts of the wide composite riverbed prevent the negative effects of flooding. The surrounding plants were carefully selected and form grassy and flowery meadows. Native species of trees, shrubs and herbs were also plated in the park. The landscaped and revitalized surroundings of the stream in the middle of the built-up area offer space for pleasant leisure time on hot days, also thanks to playground equipment for children.
The Adaptation Journey
The positive impact
The landscape-based revitalization of the approximately half-kilometre section of the Rakovský brook was aimed primarily at natural flood prevention, and at the same time building a new park for the town of Rokycany, where the local community could take refuge on hot summer days.
Rokycany emphasized the care of stone crayfish and adapted the shape of the stream to suit the crayfish’s needs and to support the overall biodiversity.
How does it work?
The original 520 meters of artificially straightened stream were replaced by meanders with ponds. Thanks to this, the length of the section of the brook was slightly extended to 538 meters. However, the biggest change that defined the composition of the park was the change in the riverbed. The town council replaced the simple riverbed with a so-called wide compound riverbed. This consists of a lowered part of the riverbed, through which the water flows at normal flow, and berm - an elevated part of the riverbed, through which water can flow during flood flows. The transition between the bottom part of the riverbed and the berm is very gradual. The wight of the berm sometimes reaches up to 40 meters.
In order to create a wide compound riverbed, the city had to arrange large terrain modelling on 3 hectares of the park. During the construction, 16,487 cubic meters of low-quality soil were dug and landfilled, the town council then had imported topsoil spread and grass sown on 22,305 square meters, which corresponds to the area of more than 3 football fields. The construction also included a specialized rescue transmission of crayfish by a professionally qualified person and during the transfer from the half-kilometre section of the river they counted about 1,500 stone crayfish.
The stream is lined with carefully selected stones to suit the local crayfish. The lowered parts of the wide compound trough, the berms, are planted firmly and with deep-rooting plants so that the water does not wash them away. The upper part of the loose riverbed is covered with flowery meadows. The town council planted more than 70 trees and 100 shrubs in the park.
The designers also wanted to achieve the least of paved areas possible – the top of main park path is made of packed gravel, other paths are created on a drainage base and sown with a grass mixture tolerant to trampling.
There are also places that allow to cross the watercourse, such as wooden platforms and a rope bridge, connecting the left and right banks of the park.
At one of the main entrances to the park, a dry terrain model of the stream bed was created with a flow-through pool, which serves as a sandpit. The non-flooding parts of the park are equipped with other objects for relaxation and playing. And winter fun was also considered. In the southern part of the park there is a slope for sledding and bobsledding.
Šťáhlavská by Rakováček Park was created on the previously almost unused land owned by the town of Rokycany between the Šťáhlavská, Sokolská and Božena Němcová streets. There was a man-made, artificially straightened riverbed of the Rakovský brook with concrete banks passing through the land.
Operation and maintenance
The costs of operation and maintenance must include the cost of continuous care for greenery and trees which is about 100 thousand CZK per year for this area. Mowing the grass costs about 200 thousand CZK (3785 EUR) a year. Once every three to five years, it is necessary to paint the furniture, which will cost approximately 70 thousand CZK (2650 EUR). Other maintenance is estimated at approximately 50 thousand CZK (1892 EUR) per year.
Why was the measure chosen?
The original idea was to landscape a longer section of the Rakovský brook. In the end, however, the project was modified due to the grant conditions.
Obstacles and challenges
During the construction, there were two changes to the original project.
The first change was caused by a highly protected kingfishers living in the area. In part of the stream, therefore, a change was made in the fortification of the riverbed to avoid covering the nesting burrows.
The second change was caused by the different conditions in the quality and quantity of topsoil that was found on the construction site. During the preparation of the project, the council found out that part of the collected soil cannot be used for landscaping. It was therefore necessary to import new soil and take the barren topsoil to a landfill.
How much did it cost?
The total cost reached CZK 17,245,202.58 (652.646 EUR).
The grant from the Operational Program Environment was almost 14 million czech crowns (529.831 EUR). The rest of the budget was covered by the municipal budget of Rokycany.
Revitalization of water elements Zieleń miejska Povodně a přívalové srážky