Foto: Vojta Herout
Pod Plachtami Park in Brno
What to do with rainwater in a housing estate? In Nový Lískovec in Brno an inspiring solution was implemented. Instead of draining, the water from the roofs of three blocks of flats flows into a lake that dominates the center of the Pod Plachtami Park. The project offers an unusual solution to the problem of overloaded sewerage during torrential rains. Combining a body of water with greenery of the park also lowers the temperature of the overheated housing estate.
The Adaptation Journey
The positive impact
Brno district of Nový Lískovec is located on a southern slope. The place is thus threatened by drought and heat. However, the park with a lake retains rainwater and has a great affect on the climate throughout the year. At the same time, it reduces the load on the sewer system, which is overloaded during torrential rains. The idea was also to create a home for aquatic organisms, insects and small vertebrates and birds.
How does it work?
The project is a pilot example of the use of rainwater in the area of Nový Lískovec - one of the most densely built-up parts of Brno in terms of population. The result is 32,000 square meters of green park area with a lake. The rainwater from the roofs of three neighboring blocks of flats flows into the lake. Trees and shrubs were planted in the northern part of the park and along the edges, in the southern part the original vegetation was supplemented with meadows with meadow flowers. Different environments provide a home for different animal and plant species. There is a nature trail with information boards in the whole park.
The park was created in an area surrounded by blocks of flats that was overgrown with trees. The area was originally intended for further development.
Operation and maintenance
The park is maintained by Brno district of Nový Lískovec. The annual cost of maintenance and management of the park does not exceed 300 000 CZK (12 000 EUR).
In the first year after the lake was built, invasive fish species such as the stone moroko and the Prussian carp multiplied in numbers and completely destroyed the plants. Predatory fish were introduced which solved the situation. In the fifth year of operation the sluice broke, the fish were caught and the lake emptied. After repairing the sluice and cleaning the bottom of the lake, it was refilled, the aquatic plants survived unharmed and the diversity quickly recovered.
Why was the measure chosen?
The project is a result of long-term planning and many discussions with citizens from 2005 to 2011. The intention was to build a water element in the urbanized area and solve the rainwater issues. Insufficient capacity of the rainwater sewer system limits further development of the city district. Increasing the capacity of the sewer, however, is extremely expensive. Therefore an ecological alternative was implemented, which in addition to lower costs brought a positive effect on the quality of housing.
Obstacles and challenges
The city district had to overcome technical obstacles. When planning, they had to meet the requirements of the operators of civil engineering infrastructure, especially Brno Water Supply and Sewerage Systems, which slightly increased the cost of the project. Negative reactions of some members of public were a surprise. Despite thorough discussions, the plan of building a water feature raised concerns about mosquitoes, odors, and child safety. None of the fears were confirmed. The water element has been working for 8 years, even in times of extreme drought and heat, no smell or dying animals occured.
How much did it cost?
The total cost for the construction of Pod Plachtami Park in Nový Lískovec in Brno reached 12 million CZK (470 thousand EUR), including the design work. Funding was provided by the Statutory City of Brno, Brno-Nový Lískovec district and the State Environmental Fund, which contributed approximately 17 % of the total amount.
The expected lifetime of the measure is assumed to be within 50 years.
Urban greenery Use of rainwater Shading Biodiversity Heat waves and thermal island Floods and torrential rainfall