In the past, the village of Dubenec often suffered from sudden floods. The local council decided to solve this problem by taking comprehensive land-improvement measures. Large plots of land were divided by infiltration strips and biocorridors. Polders and ponds were built. These changes to the terrain effectively direct rainwater, ensuring it is retained in the landscape, where it can naturally soak into the ground or evaporate. A new system for measuring the level of rainwater and groundwater sends residents emergency text messages in the event of a flood threat.
The project also made this area greener. A cider factory and a fruit-drying facility were built in the village – to process the harvest from recently planted trees. These products are sold in a shop specialising in local goods, and the proceeds partly cover the costs of caring for the trees. The area has also become a popular place for walks.
Positive impact
The local authorities introduced this project as a response to the long-standing problem of flash flooding. This measure not only protects against floods but also makes it possible to retain water in the landscape.
Since the project was implemented, the risk of floods has significantly decreased. Air humidity has improved, and local springs no longer dry up. The municipality is already working on continuing the project.
How does it work?
The first step was resolving land claims. After that the municipality carried out land consolidation, which made it possible to divide the large fields into infiltration strips and biocorridors, which were then planted with fruit trees. The land consolidation process began in 2009, but because of administrative difficulties the first changes to the terrain took place only in 2017. The project covers various sections of the Dubenec municipality’s territory with a total area of 1,213 hectares.
The adaptation consists of building anti-erosion ditches, supplemented by functional greenery and biocorridors. The latter, in particular, facilitate the movement of wild animals in the agricultural landscape. The infiltration ditches were supplemented with small dams to retain, absorb or evaporate water, which slow its runoff. Wide field margins were set aside on previously inaccessible areas, along which people can now walk.
The municipality built two reservoirs (a tank/pond) to collect rainwater. The first is semi-dry and is a wetland. It fills with drainage and rainwater arriving through green ditches along the slopes. The second has a constant inflow from a local spring. Both reservoirs are readily visited by animals and birds. The polders can hold about 5,000 m³ of water. During rain, lagoons form first, and only after they overflow does the water safely drain into the local stream. When the rain ends, the lagoons remain full – the water stays in this area.
The municipality planted 1,200 trees in the area, mostly apple and pear trees (900 of them), as well as oaks. A municipal cider factory and drying facility were built to process the harvest. Almost 30 tonnes of apples are processed here every year. The produce is sold in the municipal shop together with other regional goods, and the proceeds partly cover the costs of caring for the trees.
A system of rain- and water-level sensors connected to a central computer was installed in the rural area. In the event of a flood threat, the system automatically sends out text warnings.
The starting situation
Dubenec is a village in a valley. After the fields were merged into large plots, erosion processes intensified significantly. In 1965–1980, large-scale land drainage and levelling of watercourses were carried out here to divert excess water. Despite this, the village continued to suffer from flash floods and the associated erosion of the topsoil.
Maintenance
The municipality gained about seven hectares of new grassland with more than 1,200 trees and 400 shrubs. The project budget provides for the costs of maintaining some areas for two years after the works are completed. The rest the municipality took on immediately after construction. Care of the meadows is carried out by municipal workers using their own equipment. This costs about 140,000 Czech crowns a year. Contractors’ services, in particular pruning and transplanting trees, cost about another 90,000 crowns a year.
Why was this particular measure chosen?
Because of the limited amount of land suitable for consolidation, it was not possible to develop several options.
The main challenge was the heterogeneity of the soils: from permeable limestone and sandstone to heavy clay. The system of interconnected dams partly depends on how well the water is absorbed into the soil and evaporates.
Challenges and obstacles
The main difficulties were the construction works themselves and the negotiations with agricultural enterprises. The works required careful planning to minimise inconvenience for the farmers, who temporarily gave up plots where excavated soil was stored.
There were natural obstacles too. In particular, during sowing and planting there was a severe drought, and all available municipal equipment, including fire engines, had to be used for watering.
Operation
About a year and a half later, the number of rodents on the infiltration strips and in the biocorridors increased sharply, which led to damage to the vegetation. Therefore, municipal workers placed artificial nesting boxes for birds of prey on the trees, and installed T-shaped structures for birds to rest throughout the area. The following year, eagle-owls, buzzards and owls began to nest here.
At the same time, the excessive use of industrial fertilisers, herbicides and other chemicals on neighbouring fields still has a negative effect on the restored land.
How much did it cost?
The costs, amounting to 7 million Czech crowns, were covered from European and national subsidy funds.