Increasing the retention capacity and combating floods and drought in lowland forest ecosystems
About this good practice
Observations over the last 50 years indicate that the occurrence of extreme weather events such as droughts and heavy rainfall is increasing in Poland. In addition, past drainage irrigation in agriculture and forestry has led to a lowering of the ground and surface water table. As a result, numerous forest habitats are drying out in many areas. To meet the problems described, since the 1990s. State Forests have been implementing water retention investments. The measures taken have brought tangible benefits in the form of an increase in the water abundance of forest habitats, as well as the restoration of degraded wetland ecosystems.
As part of the project, the State Forests will use the funding obtained to implement small retention facilities in the Forest Districts in the Polish Lowlands, which will contribute to improving the water balance in small drainage basins, minimise the effects of drought in forest ecosystems and counteract flooding. One of the project's objectives is to support pro-environmental methods of water retention in forests. The project also pursued the indirect objectives of preserving the biodiversity of wetlands and renaturalising marshes and swamps
Who are the main stakeholders and beneficiaries of the practice? 175 forest districts in 17 Regional Directorates of State Forests
Resources needed
Financing: own funds of the State Forests and the Infrastructure and Environment Programme (European Union Cohesion Fund)
Evidence of success
- 3644 facilities, such as small reservoirs or water damming structures (thresholds, levees), fords, and culverts.
- 42 million m3 of water retained.
Potential for learning or transfer
Great opportunities for water retention have been created especially by the reconstruction of existing drainage systems in the direction of retarding runoff - correcting past mistakes resulting in excessive drainage. Measures that delay and reduce runoff, e.g. by damming up water in ditches, sub-basins in reservoirs, ponds and similar depressions from which water is drained by ditches, bring about an improvement in the water balance structure and an increase in biodiversity.
Among the numerous functions that the small water reservoirs and ditch damming built or renovated in the project can perform are:
- drought prevention
- flood control functions (retaining excess rainwater in forested areas, flattening flood waves in lower parts of the catchment area)
- restoration of natural water conditions in wetlands
- maintaining groundwater levels
- maintaining underground water in headwaters
- maintaining and creating sanctuaries for aquatic, wetland or periodically water-logged ecosystem