Wetland Restoration in Persina, Bulgaria
Wetlands are efficient measures to improve and regulate water quality and stream flow characteristics. This particular project in Persina, Bulgaria aimed to enable water flow into former wetlands, provide options for controlled flooding, optimized trapping of nutrient elements, and restoration of biodiversity and fish populations
The project was initiated by the Ministry of the Environment and Water of Bulgaria, which was a success factor for the implementation. The high river flow of the lower Danube makes it challenging to assess the relative impact of the NWRM due to the scale.
It is however proven that the project has played a significant role in re-connecting former wetlands, with 80% of the water regime having been restored.
The measure also impacts the overall water quality through nutrient reduction and capture (Nitrate, Phosphorous) and by capturing organic pollutants.
Improved self-purification and nutrient capture capacity of the river system contributes to mitigating the impacts of untreated urban wastewater (responding to UWWT Directive requirements) and directly contributes to the implementation of the Birds and Habitats Directives.
Regarding ecological status, the project showed positive impacts on morphological parameters (connectivity) as well as an expected positive impact on Biological Quality Elements – fish fauna. It contributes to the conservation objectives of water-dependent protected areas.
It is expected to take 10 to 15 years for the restored wetlands to reach the desired ecosystem value. The river runoff decreased by 1 to 10%, which contributes to controlling runoff, but no published data or estimation exists on peak flow rate reduction: taking into account the total runoff of the Danube River in peak flow, the overall impact on flood reduction for the Danube is limited, although nevertheless contributes an incremental improvement.
Other benefits also resulted from the application of the measure. Biodiversity has improved, with the number of birds of 22 species increasing and fish species increasing from 2 to 10 within two months of the first test flooding of Belene Island. Moreover, the wetland sites offer a chance for future tourism development in the region, new employment opportunities and economic benefits due to fishery and biomass production.
As an example, the project supported initiatives such as manufacturing charcoal briquettes from reeds harvested from the restored wetlands. Improved farming techniques and the development of organic certified crops created the potential for increased value of agricultural products and revenue for farmers.
Finally, the Danube wetland restoration introduced a new idea that wetlands are not a necessary ‘evil’, also making the landscape attractive in addition to being functional. The first follow-up project, ‘Kaikusha’, has been approved under the EU LIFE+ programme and will help develop feasibility studies to restore the Kaikusha Marshes in the Danube River basin.