Foto: Vojta Herout, www.vojtaherout.com
Rainfall Management Na Bahně
Rainwater from family houses and public areas around the Bratice village square no longer flows into the sewerage, but into the lake, which used to be an unused fire tank in a state of disrepair with an impenetrable muddy environment. Thanks to the conversion of the tank into a natural lake, the ability to retain water has significantly increased. The new rainwater sewage and ponds were complemented by wooden footbridges with piers, thanks to which it is possible to get closer to the water and cross the wet parts of the park. The water from the pond is also used to irrigate local plants. There is also water playground equipment, where not only children can have fun. There are also decently lit benches, which make the village square a pleasant place to stay not only during the day, but also at night.
The Adaptation Journey
The positive impact
Na Bahně (The Bog). This is how people in Bratčice call area which, thanks to its location, had the ambition to be the village square. Instead of that, until recently, it was a dismal muddy space with an ordinary fire tank. It was in a state of disrepair due to sediments and age, the water in it stank in the summer, and the trees in its vicinity began to be dangerous due to lack of care.
Instead of just repairing the fire tank, the locals decided to transform the whole area so that it really began to serve as a pleasant centre of the village inviting to meetings, walks and relaxing. Everything was aimed at revitalizing the village square with respect for people and nature and so that it was not necessary to drain the area. On the contrary, they began to manage water even more sparingly.
The newly modified two-hectare area Na Bahně now makes it possible to retain rainwater so that it can be used for irrigation and significantly improve the microclimate in the entire area.
How does it work?
Water was a key element in the revitalization of the area. The village turned the water reservoir into a lake with a depth of 90-120 centimetres, removed 400 tons of sediment to a depth of 3 meters, strengthened the banks and repaired the discharge facility. Thanks to the established measures, the lake will retain up to 90 % more water. In addition, the new rainwater drainage system directs rainwater from the surrounding houses through a small pre-treatment lake and thus seeps it locally. Rainwater is collected from an area of approximately 2.5 hectares.
The village also treated the local trees. It was the combination of water and trees that made it possible to create a unique path above the water, which consists of a meter and a half wide wooden walkways and wooden benches. The village used 120 cubic meters of oak and acacia wood for wooden equipment. The village council planted 39 trees, 250 shrubs and 6,000 perennials on a one-hectare lawn.
Part of the water from the pond is pumped into a collection tank with a capacity of 45 cubic meters and distributed for irrigation of new the newly planted trees, shrubs, perennials and lawns using 110 nozzles. The pump consumes a minimum amount of energy, so the system is extremely cost effective. Bratčice irrigate the village square twice a day - 9 cubic meters of water in the morning and 9 cubic meters of water in the evening.
Na Bahně now serves both for relaxing in the shade of trees and for various leisure activities. Here you will find playgound equipment right on the surface of the lake. The water playground with Archimedes screw or a set of water courses will also entertain families with small children. The area can also be used for cultural and sporting events. The village regularly organizes competitions of volunteer firefighters here.
Na Bahně space before the reconstruction represented the past, when the goal was not for the place to meet the requirements for relaxation and meeting. The tank was reinforced with concrete blocks and surrounded by unmaintained trees. The water in the tank full of sediments was smelly in the summer, and the rainwater from the surroundings drained too quickly into the Lejtna stream. There were no benches or playgrounds, the community was not attracted to the natural centre of the village.
Operation and maintenance
Maintenance costs are estimated at 30 thousand crowns. The electricity used to operate the pump plus work costs about 2,000 czech crowns a year.
Why was the measure chosen?
The council did not consider any other options.
Obstacles and challenges
The budget for wooden elements was incorrectly priced at 8500 crowns for 1 cubic meter of wood, including connecting material and work, which the contractor and the council found out about only after signing the contract.
Operation and maintenance
The landscaping created a recreational area for the community, which is used for cultural and sporting events. It also included a new fire station with the necessary facilities, which are used for training and competitions in fire sports.
How much did it cost?
The project cost about 10 million crowns (380,872 EUR), which the municipality of Bratčice invested from its own budget.
The lifetime of the measure is estimated to be around 40 years.
Revitalization of water elements Family and apartment houses Urban greenery Use of rainwater Heat waves and thermal island